Solved: Classify each species as either a Lewis acid or a

Calculate the concentration of H1 ions in a 0.62 M NaOH solution

Calculate the pH of each of the following solutions: (a) 0.0010 M HCl, (b) 0.76 M KOH.

Calculate the pH of each of the following solutions: (a) 2.8 3 1024 M Ba(OH)2, (b) 5.2 3 1024 M HNO3.

Calculate the hydrogen ion concentration in mol/L for solutions with the following pH values: (a) 2.42, (b) 11.21, (c) 6.96, (d) 15.00.

Calculate the hydrogen ion concentration in mol/L for each of the following solutions: (a) a solution whose pH is 5.20, (b) a solution whose pH is 16.00, (c) a solution whose hydroxide concentration is 3.7 3 1029 M.

Complete the following table for a solution: pH [H1] Solution is ,7 ,1.0 3 1027 M Neutral

Fill in the word acidic, basic, or neutral for the following solutions: (a) pOH . 7; solution is (b) pOH 5 7; solution is (c) pOH , 7; solution is

The pOH of a strong base solution is 1.88 at 25C. Calculate the concentration of the base (a) if the base is KOH and (b) if the base is Ba(OH)2.

Calculate the number of moles of KOH in 5.50 mL of a 0.360 M KOH solution. What is the pOH of the solution?

How much NaOH (in grams) is needed to prepare 546 mL of solution with a pH of 10.00?

A solution is made by dissolving 18.4 g of HCl in 662 mL of water. Calculate the pH of the solution. (Assume that the volume remains constant.)

Explain what is meant by the strength of an acid

Without referring to the text, write the formulas of four strong acids and four weak acids.

H2SO4 is a strong acid, but HSO4 2 is a weak acid. Account for the difference in strength of these two related species.

Which of the following diagrams best represents a strong acid, such as HCl, dissolved in water? Which represents a weak acid? Which represents a very weak acid? (The hydrated proton is shown as a hydronium ion. Water molecules are omitted for clarity.) (a) (b) (c) (d)

(1) Which of the following diagrams represents a solution of a weak diprotic acid? (2) Which diagrams represent chemically implausible situations? (The hydrated proton is shown as a hydronium ion. Water molecules are omitted for clarity.) (a) (b) (c) (d)

Classify each of the following species as a weak or strong acid: (a) HNO3, (b) HF, (c) H2SO4, (d) HSO4 2, (e) H2CO3, (f) HCO3 2, (g) HCl, (h) HCN, (i) HNO2.

Classify each of the following species as a weak or strong base: (a) LiOH, (b) CN2, (c) H2O, (d) ClO4 2, (e) NH2 2.

Which of the following statements is/are true for a 0.10 M solution of a weak acid HA? (a) The pH is 1.00. (b) [H1] @ [A2] (c) [H1] 5 [A2] (d) The pH is less than 1

Which of the following statements is/are true regarding a 1.0 M solution of a strong acid HA? (a) [A2] . [H1] (b) The pH is 0.00. (c) [H1] 5 1.0 M (d) [HA] 5 1.0 M

Predict the direction that predominates in this reaction: F2(aq) 1 H2O(l) HF(aq) 1 OH2(aq)

Predict whether the following reaction will proceed from left to right to any measurable extent: CH3COOH(aq) 1 Cl2(aq)

What does the ionization constant tell us about the strength of an acid?

List the factors on which the Ka of a weak acid depends.

Why do we normally not quote Ka values for strong acids such as HCl and HNO3? Why is it necessary to specify temperature when giving Ka values?

Which of the following solutions has the highest pH? (a) 0.40 M HCOOH, (b) 0.40 M HClO4, (c) 0.40 M CH3COOH.

The Ka for benzoic acid is 6.5 3 1025 . Calculate the pH of a 0.10 M benzoic acid solution.

A 0.0560-g quantity of acetic acid is dissolved in enough water to make 50.0 mL of solution. Calculate the concentrations of H1, CH3COO2, and CH3COOH at equilibrium. (Ka for acetic acid 5 1.8 3 1025 .)

The pH of an acid solution is 6.20. Calculate the Ka for the acid. The initial acid concentration is 0.010 M.

What is the original molarity of a solution of formic acid (HCOOH) whose pH is 3.26 at equilibrium?

Calculate the percent ionization of benzoic acid having the following concentrations: (a) 0.20 M, (b) 0.00020 M.

Calculate the percent ionization of hydrofluoric acid at the following concentrations: (a) 0.60 M, (b) 0.0046 M, (c) 0.00028 M. Comment on the trends.

A 0.040 M solution of a monoprotic acid is 14 percent ionized. Calculate the ionization constant of the acid.

(a) Calculate the percent ionization of a 0.20 M solution of the monoprotic acetylsalicylic acid (aspirin) for which Ka 5 3.0 3 1024 . (b) The pH of gastric juice in the stomach of a certain individual is 1.00. After a few aspirin tablets have been swallowed, the concentration of acetylsalicylic acid in the stomach is 0.20 M. Calculate the percent ionization of the acid under these conditions. What effect does the nonionized acid have on the membranes lining the stomach? (Hint: See the Chemistry in Action essay on p. 706.)

What are the concentrations of HSO4 2, SO4 22, and H1 in a 0.20 M KHSO4 solution?

Calculate the concentrations of H1, HCO3 2, and CO3 22 in a 0.025 M H2CO3 solution.

List four factors that affect the strength of an acid.

How does the strength of an oxoacid depend on the electronegativity and oxidation number of the central atom?

Predict the acid strengths of the following compounds: H2O, H2S, and H2Se.

Compare the strengths of the following pairs of acids: (a) H2SO4 and H2SeO4, (b) H3PO4 and H3AsO4.

Which of the following is the stronger acid: CH2ClCOOH or CHCl2COOH? Explain your choice.

Consider the following compounds: OOOH CH3OOOH phenol methanol Experimentally, phenol is found to be a stronger acid than methanol. Explain this difference in terms of the structures of the conjugate bases. (Hint: A more stable conjugate base favors ionization. Only one of the conjugate bases can be stabilized by resonance.)

Define salt hydrolysis. Categorize salts according to how they affect the pH of a solution.

Explain why small, highly charged metal ions are able to undergo hydrolysis

Al31 is not a Brnsted acid but Al(H2O)31 6 is. Explain

Specify which of the following salts will undergo hydrolysis: KF, NaNO3, NH4NO2, MgSO4, KCN, C6H5COONa, RbI, Na2CO3, CaCl2, HCOOK.

Predict the pH (. 7, , 7, or < 7) of aqueous solutions containing the following salts: (a) KBr, (b) Al(NO3)3, (c) BaCl2, (d) Bi(NO3)3.

Predict whether the following solutions are acidic, basic, or nearly neutral: (a) NaBr, (b) K2SO3, (c) NH4NO2, (d) Cr(NO3)3

A certain salt, MX (containing the M1 and X2 ions), is dissolved in water, and the pH of the resulting solution is 7.0. Can you say anything about the strengths of the acid and the base from which the salt is derived?

In a certain experiment a student finds that the pHs of 0.10 M solutions of three potassium salts KX, KY, and KZ are 7.0, 9.0, and 11.0, respectively. Arrange the acids HX, HY, and HZ in the order of increasing acid strength.

Calculate the pH of a 0.36 M CH3COONa solution.

Calculate the pH of a 0.42 M NH4Cl solution.

Predict the pH (. 7, , 7, < 7) of a NaHCO3 solution.

Predict whether a solution containing the salt K2HPO4 will be acidic, neutral, or basic.

Classify the following oxides as acidic, basic, amphoteric, or neutral: (a) CO2, (b) K2O, (c) CaO, (d) N2O5, (e) CO, (f) NO, (g) SnO2, (h) SO3, (i) Al2O3, (j) BaO.

Write equations for the reactions between (a) CO2 and NaOH(aq), (b) Na2O and HNO3(aq).

Explain why metal oxides tend to be basic if the oxidation number of the metal is low and acidic if the oxidation number of the metal is high. (Hint: Metallic compounds in which the oxidation numbers of the metals are low are more ionic than those in which the oxidation numbers of the metals are high.)

Arrange the oxides in each of the following groups in order of increasing basicity: (a) K2O, Al2O3, BaO, (b) CrO3, CrO, Cr2O3

Zn(OH)2 is an amphoteric hydroxide. Write balanced ionic equations to show its reaction with (a) HCl, (b) NaOH [the product is Zn(OH)4 22].

Consider the molecular views of an Al strip and \(\mathrm{Cu}^{2+}\) solution. Draw a similar sketch showing what happens to the atoms and ions after the Al strip is submerged in the solution for a few minutes.

What are the Lewis definitions of an acid and a base? In what way are they more general than the Brnsted definitions?

In terms of orbitals and electron arrangements, what must be present for a molecule or an ion to act as a Lewis acid (use H1 and BF3 as examples)? What must be present for a molecule or ion to act as a Lewis base (use OH2 and NH3 as examples)

Classify each of the following species as a Lewis acid or a Lewis base: (a) CO2, (b) H2O, (c) I2, (d) SO2, (e) NH3, (f) OH2, (g) H1, (h) BCl3.

Describe the following reaction in terms of the Lewis theory of acids and bases: AlCl3(s) 1 CI2(aq) AlCl2 4 (aq)

Which would be considered a stronger Lewis acid: (a) BF3 or BCl3, (b) Fe21 or Fe31? Explain.

All Brnsted acids are Lewis acids, but the reverse is not true. Give two examples of Lewis acids that are not Brnsted acids.

Determine the concentration of a NaNO2 solution that has a pH of 8.22

Determine the concentration of a NH4Cl solution that has a pH of 5.64.

The diagrams here show three weak acids HA (A 5 X, Y, or Z) in solution. (a) Arrange the acids in order of increasing Ka. (b) Arrange the conjugate bases in increasing order of Kb. (c) Calculate the percent ionization of each acid. (d) Which of the 0.1 M sodium salt solutions (NaX, NaY, or NaZ) has the lowest pH? (The hydrated proton is shown as a hydronium ion. Water molecules are omitted for clarity.) HX HY HZ

A typical reaction between an antacid and the hydrochloric acid in gastric juice is NaHCO3(s) 1 HCl(aq) NaCl(aq) 1 H2O(l) 1 CO2(g) Calculate the volume (in L) of CO2 generated from 0.350 g of NaHCO3 and excess gastric juice at 1.00 atm and 37.0C

To which of the following would the addition of an equal volume of 0.60 M NaOH lead to a solution having a lower pH? (a) water, (b) 0.30 M HCl, (c) 0.70 M KOH, (d) 0.40 M NaNO3.

The pH of a 0.0642 M solution of a monoprotic acid is 3.86. Is this a strong acid?

Like water, liquid ammonia undergoes autoionization: NH3 1 NH3 NH1 4 1 NH2 2 (a) Identify the Brnsted acids and Brnsted bases in this reaction. (b) What species correspond to H1 and OH2 and what is the condition for a neutral solution?

HA and HB are both weak acids although HB is the stronger of the two. Will it take a larger volume of a 0.10 M NaOH solution to neutralize 50.0 mL of 0.10 M HB than would be needed to neutralize 50.0 mL of 0.10 M HA?

A solution contains a weak monoprotic acid HA and its sodium salt NaA both at 0.1 M concentration. Show that [OH2] 5 Kw/Ka.

The three common chromium oxides are CrO, Cr2O3, and CrO3. If Cr2O3 is amphoteric, what can you say about the acid-base properties of CrO and CrO3?

Use the data in Table 15.3 to calculate the equilibrium constant for the following reaction: HCOOH(aq) 1 OH2(aq) HCOO2(aq) 1 H2O(l2

Use the data in Table 15.3 to calculate the equilibrium constant for the following reaction: CH3COOH(aq) 1 NO2 2 (aq) CH3COO2(aq) 1 HNO2(aq)

Most of the hydrides of Group 1A and Group 2A metals are ionic (the exceptions are BeH2 and MgH2, which are covalent compounds). (a) Describe the reaction between the hydride ion (H2) and water in terms of a Brnsted acid-base reaction. (b) The same reaction can also be classified as a redox reaction. Identify the oxidizing and reducing agents

Calculate the pH of a 0.20 M ammonium acetate (CH3COONH4) solution.

Novocaine, used as a local anesthetic by dentists, is a weak base (Kb 5 8.91 3 1026 ). What is the ratio of the concentration of the base to that of its acid in the blood plasma (pH 5 7.40) of a patient?

Which of the following is the stronger base: NF3 or NH3? (Hint: F is more electronegative than H.)

Which of the following is a stronger base: NH3 or PH3? (Hint: The NH bond is stronger than the PH bond.)

The ion product of D2O is 1.35 3 10215 at 25C. (a) Calculate pD where pD 5 2log [D1]. (b) For what values of pD will a solution be acidic in D2O? (c) Derive a relation between pD and pOD

Give an example of (a) a weak acid that contains oxygen atoms, (b) a weak acid that does not contain oxygen atoms, (c) a neutral molecule that acts as a Lewis acid, (d) a neutral molecule that acts as a Lewis base, (e) a weak acid that contains two ionizable H atoms, (f) a conjugate acid-base pair, both of which react with HCl to give carbon dioxide gas.

What is the pH of 250.0 mL of an aqueous solution containing 0.616 g of the strong acid trifluoromethane sulfonic acid (CF3SO3H)?

(a) Use VSEPR to predict the geometry of the hydronium ion, H3O1. (b) The O atom in H2O has two lone pairs and in principle can accept two H1 ions. Explain why the species H4O21 does not exist. What would be its geometry if it did exist?

HF is a weak acid, but its strength increases with concentration. Explain. (Hint: F2 reacts with HF to form HF2 2. The equilibrium constant for this reaction is 5.2 at 25C.)

When chlorine reacts with water, the resulting solution is weakly acidic and reacts with AgNO3 to give a white precipitate. Write balanced equations to represent these reactions. Explain why manufacturers of household bleaches add bases such as NaOH to their products to increase their effectiveness.

When the concentration of a strong acid is not substantially higher than 1.0 3 1027 M, the ionization of water must be taken into account in the calculation of the solutions pH. (a) Derive an expression for the pH of a strong acid solution, including the contribution to [H1] from H2O. (b) Calculate the pH of a 1.0 3 1027 M HCl solution.

Calculate the pH of a 2.00 M NH4CN solution

Calculate the concentrations of all species in a 0.100 M H3PO4 solution.

Identify the Lewis acid and Lewis base that lead to the formation of the following species: (a) AlCl2 4 , (b) Cd(CN)22 4 , (c) HCO2 3 , (d) H2SO4.

Very concentrated NaOH solutions should not be stored in Pyrex glassware. Why? (Hint: See Section 11.7.

In the vapor phase, acetic acid molecules associate to a certain extent to form dimers: 2CH3COOH(g) (CH3COOH)2(g) At 51C the pressure of a certain acetic acid vapor system is 0.0342 atm in a 360-mL flask. The vapor is condensed and neutralized with 13.8 mL of 0.0568 M NaOH. (a) Calculate the degree of dissociation () of the dimer under these conditions: (CH3COOH)2 2CH3COOH (Hint: See Problem 14.117 for general procedure.) (b) Calculate the equilibrium constant KP for the reaction in (a).

Calculate the concentrations of all the species in a 0.100 M Na2CO3 solution.

Henrys law constant for CO2 at 38C is 2.28 3 1023 mol/L ? atm. Calculate the pH of a solution of CO2 at 38C in equilibrium with the gas at a partial pressure of 3.20 atm.

Hydrocyanic acid (HCN) is a weak acid and a deadly poisonous compoundin the gaseous form (hydrogen cyanide) it is used in gas chambers. Why is it dangerous to treat sodium cyanide with acids (such as HCl) without proper ventilation?

How many grams of NaCN would you need to dissolve in enough water to make exactly 250 mL of solution with a pH of 10.00?

A solution of formic acid (HCOOH) has a pH of 2.53. How many grams of formic acid are there in 100.0 mL of the solution?

Calculate the pH of a 1-L solution containing 0.150 mole of CH3COOH and 0.100 mole of HCl.

A 1.87-g sample of Mg reacts with 80.0 mL of a HCl solution whose pH is 20.544. What is the pH of the solution after all the Mg has reacted? Assume constant volume

You are given two beakers, one containing an aqueous solution of strong acid (HA) and the other an aqueous solution of weak acid (HB) of the same concentration. Describe how you would compare the strengths of these two acids by (a) measuring the pH, (b) measuring electrical conductance, (c) studying the rate of hydrogen gas evolution when these solutions are reacted with an active metal such as Mg or Zn.

Use Le Chteliers principle to predict the effect of the following changes on the extent of hydrolysis of sodium nitrite (NaNO2) solution: (a) HCl is added, (b) NaOH is added, (c) NaCl is added, (d) the solution is diluted

Describe the hydration of SO2 as a Lewis acid-base reaction. (Hint: Refer to the discussion of the hydration of CO2 on p. 705.)

The disagreeable odor of fish is mainly due to organic compounds (RNH2) containing an amino group, NH2, where R is the rest of the molecule. Amines are bases just like ammonia. Explain why putting some lemon juice on fish can greatly reduce the odor

A solution of methylamine (CH3NH2) has a pH of 10.64. How many grams of methylamine are there in 100.0 mL of the solution?

A 0.400 M formic acid (HCOOH) solution freezes at 20.758C. Calculate the Ka of the acid at that temperature. (Hint: Assume that molarity is equal to molality. Carry your calculations to three significant figures and round off to two for Ka.)

Both the amide ion (NH2 2) and the nitride ion (N32) are stronger bases than the hydroxide ion and hence do not exist in aqueous solutions. (a) Write equations showing the reactions of these ions with water, and identify the Brnsted acid and base in each case. (b) Which of the two is the stronger base?

The atmospheric sulfur dioxide (SO2) concentration over a certain region is 0.12 ppm by volume. Calculate the pH of the rainwater due to this pollutant. Assume that the dissolution of SO2 does not affect its pressure.

Calcium hypochlorite [Ca(OCl)2] is used as a disinfectant for swimming pools. When dissolved in water it produces hypochlorous acid Ca(OCl)2(s) 1 2H2O(l) 2HClO(aq) 1 Ca(OH)2(s) which ionizes as follows: HClO(aq) H1(aq) 1 ClO2(aq) Ka 5 3.0 3 1028 As strong oxidizing agents, both HClO and ClO2 can kill bacteria by destroying their cellular components. However, too high a HClO concentration is irritating to the eyes of swimmers and too high a concentration of ClO2 will cause the ions to decompose in sunlight. The recommended pH for pool water is 7.8. Calculate the percent of these species present at this pH.

Explain the action of smelling salt, which is ammonium carbonate [(NH4)2CO3]. (Hint: The thin film of aqueous solution that lines the nasal passage is slightly basic.)

About half of the hydrochloric acid produced annually in the United States (3.0 billion pounds) is used in metal pickling. This process involves the removal of metal oxide layers from metal surfaces to prepare them for coating. (a) Write the overall and net ionic equations for the reaction between iron(III) oxide, which represents the rust layer over iron, and HCl. Identify the Brnsted acid and base. (b) Hydrochloric acid is also used to remove scale (which is mostly CaCO3) from water pipes (see p. 126). Hydrochloric acid reacts with calcium carbonate in two stages; the first stage forms the bicarbonate ion, which then reacts further to form carbon dioxide. Write equations for these two stages and for the overall reaction. (c) Hydrochloric acid is used to recover oil from the ground. It dissolves rocks (often CaCO3) so that the oil can flow more easily. In one process, a 15 percent (by mass) HCl solution is injected into an oil well to dissolve the rocks. If the density of the acid solution is 1.073 g/mL, what is the pH of the solution?

Which of the following does not represent a Lewis acid-base reaction? (a) H2O 1 H1 H3O1 (b) NH3 1 BF3 H3NBF3 (c) PF3 1 F2 PF5 (d) Al(OH)3 1 OH2 Al(OH)4 2

True or false? If false, explain why the statement is wrong. (a) All Lewis acids are Brnsted acids, (b) the conjugate base of an acid always carries a negative charge, (c) the percent ionization of a base increases with its concentration in solution, (d) a solution of barium fluoride is acidic

How many milliliters of a strong monoprotic acid solution at pH 5 4.12 must be added to 528 mL of the same acid solution at pH 5 5.76 to change its pH to 5.34? Assume that the volumes are additive.

Calculate the pH and percent ionization of a 0.80 M HNO2 solution.

Consider the two weak acids HX (molar mass 5 180 g/mol) and HY (molar mass 5 78.0 g/mol). If a solution of 16.9 g/L of HX has the same pH as one containing 9.05 g/L of HY, which is the stronger acid at these concentrations?

Hemoglobin (Hb) is a blood protein that is responsible for transporting oxygen. It can exist in the protonated form as HbH1. The binding of oxygen can be represented by the simplified equation HbH1 1 O2 HbO2 1 H1 (a) What form of hemoglobin is favored in the lungs where oxygen concentration is highest? (b) In body tissues, where the cells release carbon dioxide produced by metabolism, the blood is more acidic due to the formation of carbonic acid. What form of 7 hemoglobin is favored under this condition? (c) When a person hyperventilates, the concentration of CO2 in his or her blood decreases. How does this action affect the above equilibrium? Frequently a person who is hyperventilating is advised to breathe into a paper bag. Why does this action help the individual?

A 1.294-g sample of a metal carbonate (MCO3) is reacted with 500 mL of a 0.100 M HCl solution. The excess HCl acid is then neutralized by 32.80 mL of 0.588 M NaOH. Identify M

Prove the statement that when the concentration of a weak acid HA decreases by a factor of 10, its percent ionization increases by a factor of 110. State any assumptions.

Calculate the pH of a solution that is 1.00 M HCN and 1.00 M HF. Compare the concentration (in molarity) of the CN2 ion in this solution with that in a 1.00 M HCN solution. Comment on the difference.

Teeth enamel is hydroxyapatite [Ca3(PO4)3OH]. When it dissolves in water (a process called demineralization), it dissociates as follows: Ca5(PO4)3OH 5Ca21 1 3PO4 32 1 OH2 The reverse process, called remineralization, is the bodys natural defense against tooth decay. Acids produced from food remove the OH2 ions and thereby weaken the enamel layer. Most toothpastes contain a fluoride compound such as NaF or SnF2. What is the function of these compounds in preventing tooth decay?

Use the vant Hoff equation (see Problem 14.119) and the data in Appendix 3 to calculate the pH of water at its normal boiling point

At 28C and 0.982 atm, gaseous compound HA has a density of 1.16 g/L. A quantity of 2.03 g of this compound is dissolved in water and diluted to exactly 1 L. If the pH of the solution is 5.22 (due to the ionization of HA) at 25C, calculate the Ka of the acid.

A 10.0-g sample of white phosphorus was burned in an excess of oxygen. The product was dissolved in enough water to make 500 mL of solution. Calculate the pH of the solution at 25C

Calculate the pH of a 0.20 M NaHCO3 solution. (Hint: As an approximation, calculate hydrolysis and ionization separately first, followed by partial neutralization.)

(a) Shown here is a solution containing hydroxide ions and hydronium ions. What is the pH of the solution? (b) How many H3O1 ions would you need to draw for every OH2 ion if the pH of the solution is 5.0? The color codes are H3O1 (red) and OH2 (green). Water molecules and counter ions are omitted for clarity

In this chapter, HCl, HBr, and HI are all listed as strong acids because they are assumed to be ionized completely in water. If, however, we choose a solvent such as acetic acid that is a weaker Brnsted base than water, it is possible to rank the acids in increasing strength as HCl , HBr , HI. (a) Write equations showing proton transfer between the acids and CH3COOH. Describe how you would compare the strength of the acids in this solvent experimentally. (b) Draw a Lewis structure of the conjugate acid CH3COOH1 2

Use the data in Appendix 3 to calculate the Hrxn for the following reactions: (a) NaOH(aq) 1 HCl(aq) S NaCl(aq) 1 H2O(l) and (b) KOH(aq) 1 HNO3(aq) S KNO3(aq) 1 H2O(l). Comment on your results.

Malonic acid [CH2(COOH)2] is a diprotic acid. Compare its two Ka values with that of acetic acid (CH3COOH) (Ka ), and account for the differences in the three Ka values.

Look up the contents of a Tums tablet. How many tablets are needed to increase the pH of the gastric juice in a persons stomach from 1.2 to 1.5?

Phosphorous acid, H3PO3(aq), is a diprotic acid with Ka1 5 3 3 1022 . (a) After examining the Ka values in Table 15.5, estimate Ka2 for H3PO3(aq) and calculate the pH of a 0.10 M solution of Na2HPO3(aq). (b) The structure of H3PO3 is given in Figure 15.5. Explain why H3PO4(aq) is a triprotic acid, but H3PO3(aq) is only a diprotic acid.

Chicken egg shells are composed primarily of calcium carbonate, CaCO3. In a classic demonstration carried out in chemistry and biology classes, vinegar is used to remove the shell from an uncooked egg, revealing the semipermeable membrane that surrounds the egg keeping it intact. Refer to the Chemical Mystery on p. 774 to see a schematic diagram of a chicken egg. Estimate the minimum amount of vinegar required to remove the entire shell from the egg

Problem 1E What causes heartburn? What are some possible ways to alleviate heartburn?

Identify the conjugate base in the reaction shown here: a) HClO2 b) H2O c) H3O+ d) ClO2-

Problem 2E What are the general physical and chemical properties of acids? Of bases?

Which pair is a Brønsted–Lowry conjugate acid–base pair?

Problem 3E What is a carboxylic add? Give an example.

Consider the given acid ionization constants. Identify the strongest conjugate base. a) NO2-( aq ) b) CHO2-( aq ) c) ClO-( aq ) d) CN-( aq )

Problem 4E What is the Arrhenius definition of an acid? Of a base?

What is the OH - concentration in an aqueous solution at 25 °C in which [H3O+] = 1.9 x 10-9 M? a) 1.9 x 10-9 M b) 5.3 x 10-6 M c) 5.3 x 106 M d) 1.9 x 10-23 M

What is a hydronium ion? Does H+ exist in solution by itself?

An \(HNO_3 (aq)\) solution has a pH of 1.75. What is the molar concentration of the \(HNO_3 (aq)\) solution? a) 1.75 M b) \(5.6 \times 10^{-13} \ M\) c) 56 M d) 0.018 M

Problem 6E What is the Bronsted-Lowry definition of an acid? Of a base?

Why is there more than one definition of acid-base behavior? Which definition is the right one?

Find the pH of a 0.350 M aqueous benzoic acid solution. For benzoic acid, Ka = 6.5 x 10-5. a) 4.64 b) 4.19 c) 2.32 d) 11.68

Find the pH of a 0.155 M HClO2(aq) solution. For HClO2, Ka = 0.011. a) 0.92 b) 1.44 c) 1.39 d) 0.69

Problem 8E Describe amphoteric behavior and give an example.

Calculate the percent ionization of 1.45 M aqueous acetic acid solution. For acetic acid, Ka = 1.8 x 10-5. a) 0.35% b) 0.0018% c) 0.29% d) 0.0051%

Problem 9E What is a conjugate acid-base pair? Provide an example.

Consider two aqueous solutions of nitrous acid (HNO2). Solution A has a concentration of [HNO2] = 0.55 M and solution B has a concentration of [HNO2] = 1.25 M. Which statement about the two solutions is true? a) Solution A has the higher percent ionization and the higher pH. b) Solution B has the higher percent ionization and the higher pH. c) Solution A has the higher percent ionization and solution B has the higher pH. d) Solution B has the higher percent ionization and solution A has the higher pH.

Problem 10E Explain the difference between a strong acid and a weak acid and list one example of each.

Find the [OH-] in a 0.200 M solution of ethylamine (C2H5NH2). For ethylamine, Kb = 5.6 x 10-4. a) 11.52 M b) 2.48 M c) 0.033 M d) 0.011 M

What are diprotic and triprotic acids? List an example of each.

Which ion will form a basic solution when dissolved in water? a) Br- b) NO3- c) HSO4- d) SO32-

Problem 12E Define the acid ionization constant and explain its significance.

Write an equation for the autoionization of water and an expression for the ion product constant for water (Kw). What is the value of Kw at 25 oC?

Which compound will form an acidic solution when dissolved in water? a) NH4Cl b) NaCl c) KNO2 d) Ca(NO3)2

Find the pH of 0.175 M NaCN solution. For HCN, Ka = 4.9 x 10-10. a) 5.03 b) 11.28 c) 2.31 d) 8.97

What happens to the [OH-] of a solution when the [H3O+] is increased? Decreased?

What is the concentration of X2- in a 0.150 M solution of the diprotic acid H2X? For H2X, Ka1 = 4.5 x 10-6 and Ka2 = 1.2 x 10-11. a) 9.9 x 10-8 M b) 2.0 x 10-9 M c) 8.2 x 10-4 M d) 1.2 x 10-11 M

Problem 15E Define pH. What pH range is considered acidic? Basic? Neutral?

Which acid has the largest Ka : HClO2(aq), HBrO2(aq), or HIO2(aq)? a) HClO2(aq) b) HBrO2(aq) c) HIO2(aq) d) All three acids have the same Ka .

Problem 16E Define pOH. What pOH range is considered acidic? Basic? Neutral?

When calculating [H3O+] for weak acid solutions, we can often use the x is small approximation. Explain the nature of this approximation and why it is valid.

In most solutions containing a strong or weak acid, the autoionization of water can be neglected when calculating [H3O+]. Explain why this statement is valid.

Problem 19E What is the percent ionization of an acid? Explain what happens to the percent ionization of a weak acid as a function of the concentration of the weak acid solution.

In calculating [\(H_{3} O^+\)] for a mixture of a strong acid and weak acid, the weak acid can often be neglected. Explain why this statement is valid.

Write a generic equation showing how a weak base ionizes Water.

How can you determine if an anion will act as a weak base? Write a generic equation showing the reaction by which an anion, A-, acts as a weak base.

What is the relationship between the acid ionization constant for a weak acid \(\left(K_{\mathrm{a}}\right)\) and the base ionization constant for its conjugate base \(\left(K_{\mathrm{b}}\right)\)?

Problem 24E What kinds of cations act as weak acids? List some examples.

When calculating the \(\left[\mathrm{H}_{3} \mathrm{O}^{+}\right]\) for a polyprotic acid, the second ionization step can often be neglected. Explain why this statement is valid.

For a weak diprotic acid H2X, what is the relationship between [X2-] and Ka2 ? Under what conditions does this relationship exist?

Problem 27E For a binary acid. H — Y, which factors affect the relative ease with which the acid ionizes?

Which factors affect the relative acidity of an oxyacid?

Problem 29E What is the Lewis definition of an acid? Of a base?

Problem 30E What is a general characteristic of a Lewis acid? Of a Lewis base?

Problem 31E What is acid rain? What causes it and where is the problem the greatest?

Problem 32E What are the main detrimental effects of acid rain? What is being done to address the problem of acid rain?

Identify each substance as an acid or a base and write a chemical equation showing how it is an acid or a base according to the Arrhenius definition. a. HNO3(aq) b. NH4+(aq) c. KOH(aq) d. HC2H3O2(aq)

Identify each substance as an acid or a base and write a chemical equation showing how it is an acid or a base in aqueous solution according to the Arrhenius definition. a. NaOH(aq) b. H2SO4(aq) c. HBr(aq) d. Sr(OH)2(aq)

In each reaction, identify the Brønsted–Lowry acid, the Brønsted–Lowry base, the conjugate acid, and the conjugate base.

In each reaction, identify the Brønsted–Lowry acid, the Brønsted– Lowry base, the conjugate acid, and the conjugate base.

Write the formula for the conjugate base of each acid. a. HCl b. H2SO3 c. HCHO2 d. HF

Write the formula for the conjugate acid of each base. a. NH3 b. ClO4- c. HSO4- d. CO32-

Both H2O and H2PO4- are amphoteric. Write an equation to show how each substance can act as an acid and another equation to show how each can act as a base.

Both HCO3- and HS- are amphoteric. Write an equation to show how each substance can act as an acid and another equation to show how each can act as a base.

Classify each acid as strong or weak. If the acid is weak, write an expression for the acid ionization constant (Ka). a. HNO3 b. HCl c. HBr d. H2SO3

Classify each acid as strong or weak. If the acid is weak, write an expression for the acid ionization constant (Ka). a. HF b. HCHO2 c. H2SO4 d. H2CO3

The three diagrams represent three different solutions of the binary acid HA. Water molecules have been omitted for clarity and hydronium ions (H3O+) are represented by hydrogen ions (H+). Rank the acids in order of decreasing acid strength.

Rank the solutions in order of decreasing \(\left[\mathrm{H}_3 \mathrm{O}^{+}\right]\): \(0.10 \mathrm{M} \mathrm{HCl}; 0.10 \mathrm{M} \mathrm{HF} ; 0.10 \mathrm{M} \mathrm{HClO} ; 0.10 \mathrm{M} \mathrm{HC}_6 \mathrm{H}_5 \mathrm{O}\)

Pick the stronger base from each pair. a. F- or Cl- b. NO2- or NO3- c. F- or ClO

Pick the stronger base from each pair. a. ClO4- or ClO2- b. Cl- or H2O c. CN- or ClO

Calculate [OH-] in each aqueous solution at 25 oC, and classify the solution as acidic or basic. a. [H3O+] = 1.2 x 10-8 M b. [H3O+] = 8.5 x 10-5 M c. [H3O+] = 3.5 x 10-2 M

Calculate [H3O+] in each aqueous solution at 25 oC, and classify each solution as acidic or basic. a. [OH-] = 1.1 x 10-9 M b. [OH-] = 2.9 x 10-2 M c. [OH-] = 6.9 x 10-12 M

Calculate the pH and pOH of each solution. a. [H3O+] = 1.7 x 10-8 M b. [H3O+] = 1.0 x 10-7 M c. [H3O+] = 2.2 x 10-6 M

Calculate [H3O+] and [OH-] for each solution. a. pH = 8.55 b. pH = 11.23 c. pH = 2.87

Complete the table. (All solutions are at \(25\ ^{\circ}\mathrm{C}\).)

Complete the table. (All solutions are at 25 oC.)

Like all equilibrium constants, the value of Kw depends on temperature. At body temperature (37 oC) , Kw = 2.4 * 10-14. What are the [H3O+] and pH of pure water at body temperature?

The value of Kw increases with increasing temperature. Is the autoionization of water endothermic or exothermic?

Calculate the pH of each acid solution. Explain how the resulting pH values demonstrate that the pH of an acid solution should carry as many digits to the right of the decimal place as the number of significant figures in the concentration of the solution. [H3O+] = 0.044 M [H3O+] = 0.045 M [H3O+] = 0.046 M

Determine the concentration of H3O+ to the correct number of significant figures in a solution with each pH. Describe how these calculations show the relationship between the number of digits to the right of the decimal place in pH and the number of significant figures in concentration. pH = 2.50 pH = 2.51 pH = 2.52

For each strong acid solution, determine [H3O+], [OH-], and pH. a. 0.25 M HCl b. 0.015 M HNO3 c. a solution that is 0.052 M in HBr and 0.020 M in HNO3 d. a solution that is 0.655% HNO3 by mass (assume a density of 1.01 g/mL for the solution)

Determine the pH of each solution. a. 0.048 M HI b. 0.0895 M HClO4 c. a solution that is 0.045 M in HClO4 and 0.048 M in HCl d. a solution that is 1.09% HCl by mass (assume a density of 1.01 g/mL for the solution)

Problem 59E What mass of HI should be present in 0.250 L of solution to obtain a solution with each pH value? a. pH = 1.25 b. pH = 1.75 c. pH = 2.85

What mass of HClO4 should be present in 0.500 L of solution to obtain a solution with each pH value? a. pH = 2.50 b. pH = 1.50 c. pH = 0.50

What is the pH of a solution in which 224 mL of HCl(g), measured at 27.2 oC and 1.02 atm, is dissolved in 1.5 L of aqueous solution?

Problem 62E What volume of a concentrated HCI solution, which is 36.0% HCI by mass and has a density of 1.179 g/mL, should be used to make 5.00 L of an HCI solution with a pH of 1.8?

Determine the [H3O+] and pH of a 0.100 M solution of benzoic acid.

Determine the [H3O+] and pH of a 0.200 M solution of formic acid.

Determine the pH of an HNO2 solution of each concentration. In which cases can you not make the simplifying assumption that x is small ?

Problem 66E Determine the pH of an HF solution of each concentration. In which cases can you not make the simplifying assumption that x is small? a. 0.250 M b. 0.0500 M c. 0.0250 M

If 15.0 mL of glacial acetic acid (pure HC2H3O2) is diluted to 1.50 L with water, what is the pH of the resulting solution? The density of glacial acetic acid is 1.05 g/mL.

Problem 68E Calculate the pH of a formic acid solution that contains 1.35% formic acid by mass. (Assume a density of 1.01 g/mL for the solution.)

A 0.185 M solution of a weak acid (HA) has a pH of 2.95. Calculate the acid ionization constant (Ka) for the acid.

A 0.115 M solution of a weak acid (HA) has a pH of 3.29. Calculate the acid ionization constant (Ka) for the acid.

Problem 71E Determine the percent ionization of a 0.125 M HCN solution.

Determine the percent ionization of a 0.225 M solution of benzoic acid.

Problem 73E Calculate the percent ionization of an acetic acid solution having the given concentration, a. 1.00 M b. 0.500 M c. 0.100 M d. 0.0500 M

Problem 74E Calculate the percent ionization of a formic acid solution having the given concentration. a. 1.00 M b. 0.500 M c. 0.100 M d. 0.0500 M

A 0.148 M solution of a monoprotic acid has a percent ionization of 1.55%. Determine the acid ionization constant (Ka) for the acid.

A 0.085 M solution of a monoprotic acid has a percent ionization of 0.59%. Determine the acid ionization constant (Ka) for the acid.

Problem 77E Find the pH and percent ionization of each HF solution. a. 0.250 M HF b. 0.100 M HF c. 0.050 M HF

Find the pH and percent ionization of a 0.100 M solution of a weak monoprotic acid having the given Ka values. a. Ka = 1.0 x 10-5 b. Ka = 1.0 x 10-3 c. Ka = 1.0 x 10-1

Find the pH of each mixture of acids. a. 0.115 M in HBr and 0.125 M in HCHO2 b. 0.150 M in HNO2 and 0.085 M in HNO3 c. 0.185 M in HCHO2 and 0.225 M in HC2H3O2 d. 0.050 M in acetic acid and 0.050 M in hydrocyanic acid

Find the pH of each mixture of acids. a. 0.075 M in HNO3 and 0.175 M in HC7H5O2 b. 0.020 M in HBr and 0.015 M in HClO4 c. 0.095 M in HF and 0.225 M in HC6H5O d. 0.100 M in formic acid and 0.050 M in hypochlorous acid

For each strong base solution, determine \(\left[\mathrm{OH}^-\right],\ \left[\mathrm{H}_3\mathrm{O}^+\right]\), pH, and pOH. a. 0.15 M NaOH b. \(1.5\times10^{-3}\mathrm{\ M}\mathrm{\ Ca}(\mathrm{OH})_2\) c. \(4.8\times10^{-4}\mathrm{\ M\ }\mathrm{Sr}(\mathrm{OH})_2\) d. \(8.7\times10^{-5}\mathrm{\ M\ }\mathrm{KOH}\)

For each strong base solution, determine [OH-], [H3O+], pH, and pOH. a. 8.77 x 10-3 M LiOH b. 0.0112 M Ba(OH)2 c. 1.9 x 10-4 M KOH d. 5.0 x 10-4 M Ca(OH)2

Determine the \(\mathrm{pH}\) of a solution that is 3.85% \(\mathrm{KOH}\) by mass. Assume that the solution has density of \(1.01 \mathrm{~g} / \mathrm{mL}\).

Problem 84E Determine the pH of a solution that is 1.55% NaOH by mass. Assume that the solution has density of 1.01 g/mL.

Problem 85E What volume of 0.855 M KOH solution is required to make 3.55 L of a solution with pH of 12.4?

Problem 86E What volume of a 15.0% by mass NaOH solution, which has a density of 1.116 g/mL, should be used to make 5.00 L of an NaOH solution with a pH of 10.8?

Write equations showing how each weak base ionizes water to form OH-. Also write the corresponding expression for Kb. a. NH3 b. HCO3- c. CH3NH2

Write equations showing how each weak base ionizes water to form OH-. Also write the corresponding expression for Kb. a. CO32- b. C6H5NH2 c. C2H5NH2

Determine the [OH-], pH, and pOH of a 0.15 M ammonia solution.

Determine the [OH-], pH, and pOH of a solution that is 0.125 M in CO32-.

Caffeine \(\left(\mathrm{C}_8\mathrm{H}_{10}\mathrm{N}_4\mathrm{O}_2\right)\) is a weak base with a \(\mathrm{p} K_{\mathrm{b}}\) of 10.4. Calculate the pH of a solution containing a caffeine concentration of 455 mg/L.

Amphetamine \(\left(\mathrm{C}_{9} \mathrm{H}_{13} \mathrm{N}\right)\) is a weak base with a \(\mathrm{p} K_{\mathrm{b}}\) of 4.2. Calculate the pH of a solution containing an amphetamine concentration of 225 mg/L.

Morphine is a weak base. A 0.150 M solution of morphine has a pH of 10.5. What is Kb for morphine?

A 0.135 M solution of a weak base has a pH of 11.23. Determine Kb for the base.

Determine if each anion acts as a weak base in solution. For those anions that are basic, write an equation that shows how the anion acts as a base. a. Br- b. ClO- c. CN- d. Cl-

Determine whether each anion is basic or neutral. For those anions that are basic, write an equation that shows how the anion acts as a base. a. C7H5O2- b. I- c. NO3- d. F-

Determine the [OH-] and pH of a solution that is 0.140 M in F-.

Determine the [OH-] and pH of a solution that is 0.250 M in HCO3-.

Determine whether each cation is acidic or pH-neutral. For those cations that are acidic, write an equation that shows how the cation acts as an acid. a. \(\mathrm{NH}_{4}^{+}\) b. \(\mathrm{Na}^{+}\) c. \(\mathrm{Co}^{3+}\) d. \(\mathrm{CH}_{2} \mathrm{NH}_{3}^{+}\)

Determine whether each cation is acidic or pH-neutral. For those cations that are acidic, write an equation that shows how the cation acts as an acid. a. Sr2+ b. Mn3+ c. C5H5NH+ d. Li+

Determine if each salt will form a solution that is acidic, basic, or pH-neutral. a. FeCl3 b. NaF c. CaBr2 d. NH4Br e. C6H5NH3NO2

Determine if each salt will form a solution that is acidic, basic, or pH-neutral. a. Al(NO3)3 b. C2H5NH3NO3 c. K2CO3 d. RbI e. NH4ClO

Arrange the solutions in order of increasing acidity. \(\mathrm{NaCl},\mathrm{\ NH}_4\mathrm{Cl},\mathrm{\ NaHCO}_3,\mathrm{\ NH}_4\mathrm{ClO}_2,\mathrm{\ NaOH}\)

Arrange the solutions in order of increasing basicity. CH3NH3Br, KOH, KBr, KCN, C5H5NHNO2

Determine the pH of each solution. a. 0.10 M NH4Cl b. 0.10 M NaC2H3O2 c. 0.10 M NaCl

Determine the pH of each solution. a. \(0.20 \mathrm{M} \ \mathrm{KCHO}_{2}\) b. \(0.20 \mathrm{M} \ \mathrm{CH}_{3} \mathrm{NH}_{3} \mathrm{I}\) c. 0.20 M KI

Problem 107E Calculate the concentration of all species in a 0.15 M KF solution.

Calculate the concentration of all species in a 0.225 M C6H5NH3Cl solution.

Write chemical equations and corresponding equilibrium expressions for each of the three ionization steps of phosphoric acid.

Problem 110E Write chemical equations and corresponding equilibrium expressions for each of the two ionization steps of carbonic acid.

Calculate the [H3O+] and pH of each polyprotic acid solution. a. 0.350 M H3PO4 b. 0.350 M H2C2O4

Calculate the [H3O+] and pH of each polyprotic acid solution. a. 0.125 M H2CO3 b. 0.125 M H3C6H5O7

Calculate the concentration of all species in a 0.500 M solution of H2SO3.

Calculate the concentration of all species in a 0.155 M solution of H2CO3.

Calculate the [H3O+] and pH of each H2SO4 solution. At approximately what concentration does the x is small approximation break down? a. 0.50 M b. 0.10 M c. 0.050 M

Consider a 0.10 M solution of a weak polyprotic acid (H2A) with the possible values of Ka1 and Ka2 given here. a. Ka1 = 1.0 x 10-4 ; Ka2 = 5.0 x 10-5 b. Ka1 = 1.0 x 10-4 ; Ka2 = 1.0 x 10-5 c. Ka1 = 1.0 x 10-4 ; Ka2 = 1.0 x 10-6

Based on their molecular structure, pick the stronger acid from each pair of binary acids. Explain your choice. a. HF and HCl b. H2O or HF c. H2Se or H2S

Based on molecular structure, arrange the binary compounds in order of increasing acid strength. Explain your choice. H2Te, HI, H2S, NaH

Based on their molecular structure, pick the stronger acid from each pair of oxyacids. Explain your choice. a. H2SO4 or H2SO3 b. HClO2 or HClO c. HClO or HBrO d. CCl3COOH or CH3COOH

Based on molecular structure, arrange the oxyacids in order of increasing acid strength. Explain your choice. \(\mathrm{HClO}_3, \mathrm{HIO}_3, \mathrm{HBrO}_3\)

Which is a stronger base, S2- or Se2-? Explain.

Which is a stronger base, PO43- or AsO43-? Explain.

Classify each species as either a Lewis acid or a Lewis base. a. Fe3+ b. BH3 c. NH3 d. F-

Classify each species as either a Lewis acid or a Lewis base. a. BeCl2 b. OH- c. B(OH)3 d. CN-

Identify the Lewis acid and Lewis base from among the reactants in each equation. (a) \(\mathrm{Fe}^{3+}(a q)+6 \mathrm{H}_2 \mathrm{O}(l) \rightleftharpoons \mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6{ }^{3+}(a q)\) (b) \(\mathrm{Zn}^{2+}(a q)+4 \mathrm{NH}_3(a q) \rightleftharpoons \mathrm{Zn}\left(\mathrm{NH}_3\right)_4{ }^{2+}(a q)\) (c) \(\left(\mathrm{CH}_3\right)_3 \mathrm{~N}(\mathrm{~g})+\mathrm{BF}_3(\mathrm{~g}) \rightleftharpoons\left(\mathrm{CH}_3\right)_3 \mathrm{NBF}_3(\mathrm{~s})\)

Identify the Lewis acid and Lewis base from among the reactants in each equation.

Based on these molecular views, determine whether each pictured acid is weak or strong.

Based on these molecular views, determine whether each pictured base is weak or strong.

The binding of oxygen by hemoglobin in the blood involves the equilibrium reaction: In this equation, Hb is hemoglobin. The pH of normal human blood is highly controlled within a range of 7.35 to 7.45. Given the above equilibrium, why is this important? What would happen to the oxygen-carrying capacity of hemoglobin if blood became too acidic (a dangerous condition known as acidosis)?

Carbon dioxide dissolves in water according to the equations: Carbon dioxide levels in the atmosphere have increased about 20% over the last century. Given that Earth’s oceans are exposed to atmospheric carbon dioxide, what effect might the increased CO2 have on the pH of the world’s oceans? What effect might this change have on the limestone structures ( primarily CaCO3) of coral reefs and marine shells?

People often take milk of magnesia to reduce the discomfort associated with acid stomach or heartburn. The recommended dose is 1 teaspoon, which contains \(4.00 \times 10^2 mg\) of \(Mg(OH)_2\). What volume of an HCl solution with a pH of 1.3 can be neutralized by one dose of milk of magnesia? If the stomach contains \(2.00 \times 10^2 mL\) of pH 1.3 solution, will all the acid be neutralized? If not, what fraction will be neutralized?

Lakes that have been acidified by acid rain can be neutralized by liming, the addition of limestone (CaCO3). How much limestone (in kg) is required to completely neutralize a 4.3 billion liter lake with a pH of 5.5?

Acid rain over the Great Lakes has a pH of about 4.5. Calculate the \(\left[\mathrm{H}_{3} \mathrm{O}^{+}\right]\) of this rain and compare that value to the \(\left[\mathrm{H}_{3} \mathrm{O}^{+}\right]\) of rain over the West Coast that has a pH of 5.4. How many times more concentrated is the acid in rain over the Great Lakes?

White wines tend to be more acidic than red wines. Find the [H3O+] in a Sauvignon Blanc with a pH of 3.23 and a Cabernet Sauvignon with a pH of 3.64. How many times more acidic is the Sauvignon Blanc?

The AIDS drug zalcitabine (also known as ddC) is a weak base with the structure shown here and a pKb of 9.8. What percentage of the base is protonated in an aqueous zalcitabine solution containing 565 mg/L?

Common aspirin is acetylsalicylic acid, which has the structure shown here and a pKa of 3.5. Calculate the pH of a solution in which one normal adult dose of aspirin ( 6.5 x 102 mg ) is dissolved in 8.0 ounces of water.

Determine the pH of each solution. a. 0.0100 M HClO4 b. 0.115 M HClO2 c. 0.045 M Sr(OH)2 d. 0.0852 M KCN e. 0.155 M NH4Cl

Determine the pH of each two-component solution. a. 0.0550 M in HI and 0.00850 M in HF b. 0.112 M in NaCl and 0.0953 M in KF c. 0.132 M in \(\mathrm{NH}_{4} \mathrm{Cl}\) and 0.150 M \(\mathrm{HNO}_{3}\) d. 0.0887 M in sodium benzoate and 0.225 M in potassium bromide e. 0.0450 M in HCl and 0.0225 M in \(\mathrm{HNO}_{3}\)

Determine the pH of each solution. a. 0.0650 M HNO3 b. 0.150 M HNO2 c. 0.0195 M KOH d. 0.245 M CH3NH3I e. 0.318 M KC6H5O

Determine the pH of each two-component solution. a. 0.050 M KOH and 0.015 M Ba(OH)2 b. 0.265 M NH4NO3 and 0.102 M HCN c. 0.075 M RbOH and 0.100 M NaHCO3 d. 0.088 M HClO4 and 0.022 M KOH e. 0.115 M NaClO and 0.0500 M KI

Problem 141E Write net ionic equations for the reactions that take place when aqueous solutions of the following substances are mixed: a. sodium cyanide and nitric acid b. ammonium chloride and sodium hydroxide c. sodium cyanide and ammonium bromide d. potassium hydrogen sulfate and lithium acetate e. sodium hypochlorite and ammonia

Morphine has the formula C17H19NO3. It is a base and accepts one proton per molecule. It is isolated from opium. A 0.682 g sample of opium is found to require 8.92 mL of a 0.0116 M solution of sulfuric acid for neutralization. Assuming that morphine is the only acid or base present in opium, calculate the percent morphine in the sample of opium.

The pH of a 1.00 M solution of urea, a weak organic base, is 7.050. Calculate the Ka of protonated urea.

Problem 144E A solution is prepared by dissolving 0.10 mol of acetic acid and 0.10 mol of ammonium chloride in enough water to make 1.0 L of solution. Find the concentration of ammonia in the solution.

Lactic acid is a weak acid found in milk. Its calcium salt is a source of calcium for growing animals. A saturated solution of this salt, which we can represent as Ca(Lact)2 has a [Ca2+] = 0.26 M and a pH = 8.40. Assuming the salt is completely dissociated, calculate the Ka of lactic acid.

A solution of 0.23 mol of the chloride salt of protonated quinine (QH+), a weak organic base, in 1.0 L of solution has pH = 4.58. Find the Kb of quinine (Q).

A student mistakenly calculates the pH of a 1.0 x 10-7 M HI solution to be 7.0. Explain why the student is incorrect and calculate the correct pH.

When 2.55 g of an unknown weak acid (HA) with a molar mass of 85.0 g/mol is dissolved in 250.0 g of water, the freezing point of the resulting solution is -0.257 oC. Calculate Ka for the unknown weak acid.

Calculate the pH of a solution that is 0.00115 M in HCl and 0.0100 M in HClO2.

To what volume should you dilute 1 L of a solution of a weak acid HA to reduce the [H+] to one-half of that in the original solution?

Basicity in the gas phase can be defined as the proton affinity of the base, for example, \(\mathrm{CH}_3\mathrm{NH}_2(\mathrm{g})+\mathrm{H}^+(\mathrm{g})\ \rightleftharpoons\mathrm{\ CH}_3\mathrm{NH}_3^+(\mathrm{g})\). In the gas phase, \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{N}\) is more basic than \(\mathrm{CH}_{3} \mathrm{NH}_{2}\) while in solution the reverse is true. Explain this observation.

HA, a weak acid, with Ka = 1.0 x 10-8, also forms the ion HA2-. The reaction is HA(aq) + A-(aq) ? HA2-(aq) and its K = 4.0. Calculate the [H+], [A-], and [HA2 -] in a 1.0 M solution of HA.

Calculate the pH of a solution prepared from 0.200 mol of NH4CN and enough water to make 1.00 L of solution.

To 1.0 L of a 0.30 M solution of HClO2 is added 0.20 mol of NaF. Calculate the [HClO2] at equilibrium.

A mixture of Na2CO3 and NaHCO3 has a mass of 82.2 g. It is dissolved in 1.00 L of water and the pH is found to be 9.95. Find the mass of NaHCO3 in the mixture.

A mixture of NaCN and NaHSO4 consists of a total of 0.60 mol. When the mixture is dissolved in 1.0 L of water and comes to equilibrium the pH is found to be 9.9. Find the amount of NaCN in the mixture.

Without doing any calculations, determine which solution in each pair is more acidic. a. 0.0100 M in HCl and 0.0100 M in KOH b. 0.0100 M in HF and 0.0100 M in KBr c. 0.0100 M in NH4Cl and 0.0100 M in CH3NH3Br d. 0.100 M in NaCN and 0.100 M in CaCl2

Without doing any calculations, determine which solution in each pair is more basic. a. 0.100 M in NaClO and 0.100 M in NaF b. 0.0100 M in KCl and 0.0100 M in KClO2 c. 0.0100 M in HNO3 and 0.0100 M in NaOH d. 0.0100 M in NH4Cl and 0.0100 M in HCN

Rank the acids in order of increasing acid strength. CH3COOH CH2ClCOOH CHCl2COOH CCl3COOH