Starting with either benzene or toluene, how would you synthesize the following

A solution is prepared by mixing 1.00 g ethanol (C2H5OH) with 100.0 g water to give a final volume of 101 mL. Calculate the molarity, mass percent, mole fraction, and molality of ethanol in this solution.

You are given two aqueous solutions with different ionic solutes (Solution A and Solution B). What if you are told that Solution A has a greater concentration than Solution B by mass percent, but Solution B has a greater concentration than Solution A in terms of molality? Is this possible? If not, explain why not. If it is possible, provide example solutes for A and B and justify your answer with calculations.

The electrolyte in automobile lead storage batteries is a 3.75 M sulfuric acid solution that has a density of 1.230 g/mL. Calculate the mass percent, molality, and normality of the sulfuric acid.

You and a friend are studying for a chemistry exam. What if your friend tells you, Since exothermic processes are favored and the sign of the enthalpy change tells us whether or not a process is endothermic or exothermic, the sign of DHsoln tells us whether or not a solution will form? How would you explain to your friend that this conclusion is not correct? What part, if any, of what your friend says is correct?

Decide whether liquid hexane (C6H14) or liquid methanol (CH3OH) is the more ap propriate solvent for the substances grease (C20H42) and potassium iodide (KI).

A certain soft drink is bottled so that a bottle at 258C contains CO2 gas at a pressure of 5.0 atm over the liquid. Assuming that the partial pressure of CO2 in the atmosphere is 4.0 3 1024 atm, calculate the equilibrium concentrations of CO2 in the soda both before and after the bottle is opened. The Henrys law constant for CO2 in aqueous solution is 3.1 3 1022 mol/L ? atm at 258C.

Calculate the expected vapor pressure at 258C for a solution prepared by dissolving 158.0 g common table sugar (sucrose, molar mass 5 342.3 g/mol) in 643.5 cm3 of water. At 258C, the density of water is 0.9971 g/cm3 and the vapor pressure is 23.76 torr.

Predict the vapor pressure of a solution prepared by mixing 35.0 g solid Na2SO4 (molar mass 5 142.05 g/mol) with 175 g water at 258C. The vapor pressure of pure water at 258C is 23.76 torr.

A solution is prepared by mixing 5.81 g acetone (C3H6O, molar mass 5 58.1 g/mol) and 11.9 g chloroform (HCCl3, molar mass 5 119.4 g/mol). At 358C, this solution has a total vapor pressure of 260. torr. Is this an ideal solution? The vapor pressures of pure acetone and pure chloroform at 358C are 345 and 293 torr, respectively

A solution was prepared by dissolving 18.00 g glucose in 150.0 g water. The resulting solution was found to have a boiling point of 100.348C. Calculate the molar mass of glucose. Glucose is a molecular solid that is present as individual molecules in solution

What mass of ethylene glycol (C2H6O2, molar mass 5 62.1 g/mol), the main component of antifreeze, must be added to 10.0 L water to produce a solution for use in a cars radiator that freezes at 210.08F (223.38C)? Assume the density of water is exactly 1 g/mL.

A chemist is trying to identify a human hormone that controls metabolism by determining its molar mass. A sample weighing 0.546 g was dissolved in 15.0 g benzene, and the freezing-point depression was determined to be 0.2408C. Calculate the molar mass of the hormone.

Consider the model of osmotic pressure as shown in Fig. 11.18. What if both sides contained a different pure solvent, each with a different vapor pressure? What would the system look like at equilibrium? Assume the different solvent molecules are able to pass through the membrane.

To determine the molar mass of a certain protein, 1.00 3 1023 g of it was dissolved in enough water to make 1.00 mL of solution. The osmotic pressure of this solution was found to be 1.12 torr at 25.08C. Calculate the molar mass of the protein.

What concentration of sodium chloride in water is needed to produce an aqueous solution isotonic with blood (P 5 7.70 atm at 258C)?

The observed osmotic pressure for a 0.10-M solution of Fe(NH4)2(SO4)2 at 258C is 10.8 atm. Compare the expected and experimental values for i.

The four most common ways to describe solution composition are mass percent, mole fraction, molarity, and molality. Define each of these solution composition terms. Why is molarity temperature-dependent, whereas the other three solution composition terms are temperature-independent?

Using KF as an example, write equations that refer to DHsoln and DHhyd. Lattice energy was defined in Chapter 8 as DH for the reaction K1(g) 1 F2(g) h KF(s). Show how you would utilize Hesss law to calculate DHsoln from DHhyd and DHLE for KF, where DHLE 5 lattice energy. DHsoln for KF, as for other soluble ionic compounds, is a relatively small number. How can this be since DHhyd and DHLE are relatively large negative numbers?

What does the axiom like dissolves like mean? There are four types of solute/solvent combinations: polar solutes in polar solvents, nonpolar solutes in polar solvents, and so on. For each type of solution, discuss the magnitude of DHsoln.

Structure, pressure, and temperature all have an effect on solubility. Discuss each of their effects. What is Henrys law? Why does Henrys law not work for HCl(g)? What do the terms hydrophobic and hydrophilic mean?

Define the terms in Raoults law. Figure 11.9 illustrates the net transfer of water molecules from pure water to an aqueous solution of a nonvolatile solute. Explain why eventually all of the water from the beaker of pure water will transfer to the aqueous solution. If the experiment illustrated in Fig. 11.9 was performed using a volatile solute, what would happen? How do you calculate the total vapor pressure when both the solute and solvent are volatile?

In terms of Raoults law, distinguish between an ideal liquidliquid solution and a nonideal liquidliquid solution. If a solution is ideal, what is true about DHsoln, DT for the solution formation, and the interactive forces within the pure solute and pure solvent as compared to the interactive forces within the solution? Give an example of an ideal solution. Answer the previous two questions for solutions that exhibit either negative or positive deviations from Raoults law.

Vapor-pressure lowering is a colligative property, as are freezing-point depression and boiling-point elevation. What is a colligative property? Why is the freezing point depressed for a solution as compared to the pure solvent? Why is the boiling point elevated for a solution as compared to the pure solvent? Explain how to calculate DT for a freezing-point depression problem or a boiling-point elevation problem. Of the solvents listed in Table 11.5, which would have the largest freezing-point depression for a 0.50 molal solution? Which would have the smallest boiling-point elevation for a 0.50 molal solution? A common application of freezing-point depression and boiling-point elevation experiments is to provide a means to calculate the molar mass of a nonvolatile solute. What data are needed to calculate the molar mass of a nonvolatile solute? Explain how you would manipulate these data to calculate the molar mass of the nonvolatile solute.

What is osmotic pressure? How is osmotic pressure calculated? Molarity units are used in the osmotic pressure equation. When does the molarity of a solution approximately equal the molality of the solution? Before refrigeration was common, many foods were preserved by salting them heavily, and many fruits were preserved by mixing them with a large amount of sugar (fruit preserves). How do salt and sugar act as preservatives? Two applications of osmotic pressure are dialysis and desalination. Explain these two processes.

Distinguish between a strong electrolyte, a weak electrolyte, and a nonelectrolyte. How can colligative properties be used to distinguish between them? What is the vant Hoff factor? Why is the observed freezingpoint depression for electrolyte solutions sometimes less than the calculated value? Is the discrepancy greater for concentrated or dilute solutions?

What is a colloidal dispersion? Give some examples of colloids. The Tyndall effect is often used to distinguish between a colloidal suspension and a true solution. Explain. The destruction of a colloid is done through a process called coagulation. What is coagulation?

Consider Fig. 11.9. According to the caption and picture, water seems to go from one beaker to another. a. Explain why this occurs. b. The explanation in the text uses terms such as vapor pressure and equilibrium. Explain what these have to do with the phenomenon. For example, what is coming to equilibrium? c. Does all the water end up in the second beaker? d. Is water evaporating from the beaker containing the solution? If so, is the rate of evaporation increasing, decreasing, or staying constant? Draw pictures to illustrate your explanations

Once again, consider Fig. 11.9. Suppose instead of having a nonvolatile solute in the solvent in one beaker, the two beakers contain different volatile liquids. That is, suppose one beaker contains liquid A (Pvap 5 50 torr) and the other beaker contains liquid B (Pvap 5 100 torr). Explain what happens as time passes. How is this similar to the first case (shown in the figure)? How is it different?

Assume that you place a freshwater plant into a saltwater solution and examine it under a microscope. What happens to the plant cells? What if you placed a saltwater plant in pure water? Explain. Draw pictures to illustrate your explanations.

How does DHsoln relate to deviations from Raoults law? Explain

You have read that adding a solute to a solvent can both increase the boiling point and decrease the freezing point. A friend of yours explains it to you like this: The solute and solvent can be like salt in water. The salt gets in the way of freezing in that it blocks the water molecules from joining together. The salt acts like a strong bond holding the water molecules together so that it is harder to boil. What do you say to your friend?

You drop an ice cube (made from pure water) into a saltwater solution at 08C. Explain what happens and why

Using the phase diagram for water and Raoults law, explain why salt is spread on the roads in winter (even when it is below freezing)

You and your friend are each drinking cola from separate 2-L bottles. Both colas are equally carbonated. You are able to drink 1 L of cola, but your friend can drink only about half a liter. You each close the bottles and place them in the refrigerator. The next day when you each go to get the colas, whose will be more carbonated and why?

Is molality or molarity dependent on temperature? Explain your answer. Why is molality, and not molarity, used in the equations describing freezing-point depression and boilingpoint elevation?

Consider a beaker of salt water sitting open in a room. Over time, does the vapor pressure increase, decrease, or stay the same? Explain.

Rubbing alcohol contains 585 g isopropanol (C3H7OH) per liter (aqueous solution). Calculate the molarity.

What mass of sodium oxalate (Na2C2O4) is needed to prepare 0.250 L of a 0.100-M solution?

What volume of 0.25 M HCl solution must be diluted to prepare 1.00 L of 0.040 M HCl?

What volume of a 0.580-M solution of CaCl2 contains 1.28 g solute?

Calculate the sodium ion concentration when 70.0 mL of 3.0 M sodium carbonate is added to 30.0 mL of 1.0 M sodium bicarbonate.

Write equations showing the ions present after the following strong electrolytes are dissolved in water. a. HNO3 f. NH4Br b. Na2SO4 g. NH4NO3 c. Al(NO3)3 h. CuSO4 d. SrBr2 i. NaOH e. KClO4

Rationalize the temperature dependence of the solubility of a gas in water in terms of the kinetic molecular theory

The weak electrolyte NH3(g) does not obey Henrys law. Why? O2(g) obeys Henrys law in water but not in blood (an aqueous solution). Why?

The two beakers in the sealed container illustrated below contain pure water and an aqueous solution of a volatile solute. Water Aqueous solution If the solute is less volatile than water, explain what will happen to the volumes in the two containers as time passes

The following plot shows the vapor pressure of various solutions of components A and B at some temperature. 0 PA PB 1 Mole fraction B Vapor pressure (torr) Which of the following statements is false concerning solutions of A and B? a. The solutions exhibit negative deviations from Raoults law. b. DHsoln for the solutions should be exothermic. c. The intermolecular forces are stronger in solution than in either pure A or pure B. d. Pure liquid B is more volatile than pure liquid A. e. The solution with xB 5 0.6 will have a lower boiling point than either pure A or pure B

When pure methanol is mixed with water, the resulting solution feels warm. Would you expect this solution to be ideal? Explain

Detergent molecules can stabilize the emulsion of oil in water as well as remove dirt from soiled clothes. A typical detergent is sodium dodecylsulfate, or SDS, and it has a formula of CH3(CH2)10CH2SO4 2Na1. In aqueous solution, SDS suspends oil or dirt by forming small aggregates of detergent anions called micelles. Propose a structure for micelles.

For an acid or a base, when is the normality of a solution equal to the molarity of the solution and when are the two concentration units different?

In order for sodium chloride to dissolve in water, a small amount of energy must be added during solution formation. This is not energetically favorable. Why is NaCl so soluble in water?

Which of the following statements is(are) true? Correct the false statements. a. The vapor pressure of a solution is directly related to the mole fraction of solute. b. When a solute is added to water, the water in solution has a lower vapor pressure than that of pure ice at 08C. c. Colligative properties depend only on the identity of the solute and not on the number of solute particles present. d. When sugar is added to water, the boiling point of the solution increases above 1008C because sugar has a higher boiling point than water

Is the following statement true or false? Explain your answer. When determining the molar mass of a solute using boilingpoint or freezing-point data, camphor would be the best solvent choice of all of the solvents listed in Table 11.5

Explain the terms isotonic solution, crenation, and hemolysis. 28. What is ion pairing?

A solution of phosphoric acid was made by dissolving 10.0 g H3PO4 in 100.0 mL water. The resulting volume was 104 mL. Calculate the density, mole fraction, molarity, and molality of the solution. Assume water has a density of 1.00 g/cm3 .

An aqueous antifreeze solution is 40.0% ethylene glycol (C2H6O2) by mass. The density of the solution is 1.05 g/cm3 . Calculate the molality, molarity, and mole fraction of the ethylene glycol.

Common commercial acids and bases are aqueous solutions with the following properties: Density (g/cm3) Mass Percent of Solute Hydrochloric acid 1.19 38 Nitric acid 1.42 70. Sulfuric acid 1.84 95 Acetic acid 1.05 99 Ammonia 0.90 28 Calculate the molarity, molality, and mole fraction of each of the preceding reagents.

In lab you need to prepare at least 100 mL of each of the following solutions. Explain how you would proceed using the given information. a. 2.0 m KCl in water (density of H2O 5 1.00 g/cm3 ) b. 15% NaOH by mass in water (d 5 1.00 g/cm3 ) c. 25% NaOH by mass in CH3OH (d 5 0.79 g/cm3 ) d. 0.10 mole fraction of C6H12O6 in water (d 5 1.00 g/cm3

A solution is prepared by mixing 25 mL pentane (C5H12, d 5 0.63 g/cm3 ) with 45 mL hexane (C6H14, d 5 0.66 g/cm3 ). Assuming that the volumes add on mixing, calculate the mass percent, mole fraction, molality, and molarity of the pentane.

A solution is prepared by mixing 50.0 mL toluene (C6H5CH3, d 5 0.867 g/cm3 ) with 125 mL benzene (C6H6, d 5 0.874 g/cm3 ). Assuming that the volumes add on mixing, calculate the mass percent, mole fraction, molality, and molarity of the toluene

A bottle of wine contains 12.5% ethanol by volume. The density of ethanol (C2H5OH) is 0.789 g/cm3 . Calculate the concentration of ethanol in wine in terms of mass percent and molality.

Calculate the molarity and mole fraction of acetone in a 1.00-m solution of acetone (CH3COCH3) in ethanol (C2H5OH). (Density of acetone 5 0.788 g/cm3 ; density of ethanol 5 0.789 g/cm3 .) Assume that the volumes of acetone and ethanol add

A 1.37-M solution of citric acid (H3C6H5O7) in water has a density of 1.10 g/cm3 . Calculate the mass percent, molality, mole fraction, and normality of the citric acid. Citric acid has three acidic protons.

Calculate the normality of each of the following solutions. a. 0.250 M HCl b. 0.105 M H2SO4 c. 5.3 3 1022 M H3PO4 d. 0.134 M NaOH e. 0.00521 M Ca(OH)2 What is the equivalent mass for each of the acids or bases listed above?

The lattice energy* of NaI is 2686 kJ/mol, and the enthalpy of hydration is 2694 kJ/mol. Calculate the enthalpy of solution per mole of solid NaI. Describe the process to which this enthalpy change applies

a. Use the following data to calculate the enthalpy of hydration for calcium chloride and calcium iodide. Lattice Energy DHsoln CaCl2(s) 22247 kJ/mol 246 kJ/mol CaI2(s) 22059 kJ/mol 2104 kJ/mol b. Based on your answers to part a, which ion, Cl2 or I2, is more strongly attracted to water?

Although Al(OH)3 is insoluble in water, NaOH is very soluble. Explain in terms of lattice energies

The high melting points of ionic solids indicate that a lot of energy must be supplied to separate the ions from one another. How is it possible that the ions can separate from one another when soluble ionic compounds are dissolved in water, often with essentially no temperature change?

Monobromination of toluene gives a mixture of three bromotoluene products. Draw and name them.

Propose a mechanism for the electrophilic fluorination of benzene with \(F-T E D A-B F_{4}\) Equation Transcription: Text Transcription: F-T E D A-B F_{4}

How many products might be formed on chlorination of o-xylene (o-dimethylbenzene), m-xylene, and p-xylene?

When benzene is treated with \(\mathrm{D}_{2} \mathrm{SO}_{4}\), deuterium slowly replaces all six hydrogens in the aromatic ring. Explain. Equation Transcription: Text Transcription: D_2SO_4

The Friedel–Crafts reaction of benzene with 2-chloro-3-methylbutane in the presence of \(\mathrm{AlCl}_{3}\) occurs with a carbocation rearrangement. What is the structure of the product? Equation Transcription: Text Transcription: AlCl_3

Which of the following alkyl halides would you expect to undergo Friedel– Crafts reaction with rearrangement and which without? Explain. (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Cl}\) (b) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}(\mathrm{Cl}) \mathrm{CH}_{3}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Cl}\) (d) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CCH}_{2} \mathrm{Cl}\) (e) Chlorocyclohexane Equation Transcription: Text Transcription: CH_3CH_2Cl CH_3CH_2CH(Cl)CH_3 CH_3CH_2CH_2Cl (CH_3)_3CCH_2Cl

What is the major monosubstitution product from the Friedel–Crafts reaction of benzene with 1-chloro-2-methylpropane in the presence of \(\mathrm{AlCl}_{3}\)? Equation Transcription: Text Transcription: AlCl_3

Identify the carboxylic acid chloride that might be used in a Friedel–Crafts acylation reaction to prepare each of the following acylbenzenes:

Predict the major product of the sulfonation of toluene.

Rank the compounds in each of the following groups in order of their reactivity to electrophilic substitution: (a) Nitrobenzene, phenol, toluene, benzene (b) Phenol, benzene, chlorobenzene, benzoic acid (c) Benzene, bromobenzene, benzaldehyde, aniline

Predict the major products of the following reactions: (a) Nitration of bromobenzene (b) Bromination of nitrobenzene (c) Chlorination of phenol (d) Bromination of aniline

se Figure 16-11 to explain why Friedel–Crafts alkylations often give polysubstitution but Friedel–Crafts acylations do not. Equation Transcription: Text Transcription: CH_3Cl AlCl_3 CH_3 H_3C CH_3 CH_3CCl AlCl_3 CCH_3

An electrostatic potential map of (trifluoromethyl)benzene, \(C_{6} H_{5} C F_{3}\), is shown. Would you expect (trifluoromethyl)benzene to be more reactive or less reactive than toluene toward electrophilic substitution? Explain. Equation Transcription: Text Transcription: C_{6} H_{5} C F_{3}

Acetanilide is less reactive than aniline toward electrophilic substitution. Explain. Equation Transcription: Text Transcription: CH_3

Draw resonance structures for the intermediates from the reaction of an electrophile at the ortho, meta, and para positions of nitrobenzene. Which intermediates are most stable?

What product would you expect from bromination of p-methylbenzoic acid?

At what position would you expect electrophilic substitution to occur in each of the following substances? Equation Transcription: Text Transcription: OCH_3 Br NH_2 Br Cl NO_2

Show the major product(s) from reaction of the following substances with (1) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Cl}, \mathrm{AlCl}_{3}\) and (2) \(\mathrm{HNO}_{3}, \mathrm{H}_{2} \mathrm{SO}_{4}\): Equation Transcription: Text Transcription: CH_3CH_2Cl, AlCl_3 HNO_3, H_2SO_4

The herbicide oxyfluorfen can be prepared by reaction between a phenol and an aryl fluoride. Propose a mechanism. Equation Transcription: Text Transcription: CF_3 CH_2CH_3 NO_2 CF_3 CH_2CH_3 NO_2

Treatment of p-bromotoluene with NaOH at \(300^{\circ} \mathrm{C}\) yields a mixture of two products, but treatment of m-bromotoluene with NaOH yields a mixture of three products. Explain. Equation Transcription: ? Text Transcription: 300°C

What aromatic products would you obtain from the \(\mathrm{KMnO}_{4}\) oxidation of the following substances? Equation Transcription: Text Transcription: KMnO_4 O_2N CH(CH_3)_2 H_3C Cl(CH_3)_3

Refer to Table 6-3 on page 170 for a quantitative idea of the stability of a benzyl radical. How much more stable (in kJ/mol) is the benzyl radical than a primary alkyl radical? How does a benzyl radical compare in stability to an allyl radical?

Styrene, the simplest alkenylbenzene, is prepared commercially for use in plastics manufacture by catalytic dehydrogenation of ethylbenzene. How might you prepare styrene from benzene using reactions you’ve studied?

How would you prepare diphenylmethane, \((\mathrm{Ph})_{2} \mathrm{CH}_{2}\), from benzene and an acid chloride? Equation Transcription: Text Transcription: (Ph)_2CH_2

“What is an immediate precursor of toluene?” Benzene, which could be methylated in a Friedel–Crafts reaction. Alternatively, “What is an immediate precursor of bromo benzene?” Benzene, which could be brominated. The retrosynthetic analysis has provided two valid routes from benzene to 4-bromo-2-nitrotoluene. Equation Transcription: Text Transcription: CH_3Cl AlCl_3 CH_3 Br_2 FeBr_3 CH_3 Br HNO_3 H_2SO_4 CH_3 Br NO_2 Br_2 FeBr_3 CH_3Cl AlCl_3

How might you synthesize the following substances from benzene? (a) m-Chloronitrobenzene (b) m-Chloroethylbenzene (c) 4-Chloro-1-nitro-2-propylbenzene (d) 3-Bromo-2-methylbenzenesulfonic acid

In planning a synthesis, it’s as important to know what not to do as to know what to do. As written, the following reaction schemes have flaws in them. What is wrong with each? Equation Transcription: Text Transcription: CH_3CH_2COCl,AlCl3 HNO_3,H_2SO_4 O_2N CH_2CH_3 CH_3CH_2CH_2Cl,AlCl_3 Cl_2,FeCl_3 CH_3CH_2CH_2

Draw the product from reaction of each of the following substances with (1) \(\mathrm{Br}_{2}, \mathrm{FeBr}_{3}\) and (2) \(\mathrm{CH}_{3} \mathrm{COCl}, \mathrm{AlCl}_{3}\). Equation Transcription: Text Transcription: Br_2, FeBr_3 CH_3COCl, AlCl_3

The following molecular model of a dimethyl-substituted biphenyl represents the lowest-energy conformation of the molecule. Why are the two benzene rings tilted at a 63° angle to each other rather than being in the same plane so that their p orbitals overlap? Why doesn’t complete rotation around the single bond joining the two rings occur?

How would you synthesize the following compound starting from benzene? More than one step is needed.

The following compound can’t be synthesized using the methods discussed in this chapter. Why not?

Aromatic iodination can be carried out with a number of reagents, including iodine monochloride, ICl. What is the direction of polarization of ICl? Propose a mechanism for the iodination of an aromatic ring with ICl.

The sulfonation of an aromatic ring with \(\mathrm{SO}_{3} \text { and } \mathrm{H}_{2} \mathrm{SO}_{4}\) is reversible. That is, heating benzenesulfonic acid with \(\mathrm{H}_{2} \mathrm{SO}_{4}\) yields benzene. Show the mechanism of the desulfonation reaction. What is the electrophile? Equation Transcription: Text Transcription: SO_3 and H_2SO_4 H_2SO_4

The carbocation electrophile in a Friedel–Crafts reaction can be generated by an alternate means than reaction of an alkyl chloride with \(\mathrm{AlCl}_{3}\). For example, reaction of benzene with 2-methylpropene in the presence of \(\mathrm{H}_{3} \mathrm{PO}_{4}\) yields tert-butylbenzene. Propose a mechanism for this reaction. Equation Transcription: Text Transcription: AlCl_3 H_3PO_4

The N,N,N-trimethylammonium group, \(-\stackrel{+}{\mathrm{N}}\left(\mathrm{CH}_{3}\right)_{3}\), is one of the few groups that is a meta-directing deactivator yet has no electronwithdrawing resonance effect. Explain. Equation Transcription: Text Transcription: -\stackrel+N ({CH}_{3})_3

The nitroso group,\(-N=O\), is one of the few nonhalogens that is an ortho- and para-directing deactivator. Explain this behavior by drawing resonance structures of the carbocation intermediates in ortho, meta, and para electrophilic reaction on nitrosobenzene, \(C_{6} H_{5} N=O\). Equation Transcription: Text Transcription: -N=O C_6H_5N = O

Triphenylmethane can be prepared by reaction of benzene and chloroform in the presence of \(\mathrm{AlCl}_{3}\). Propose a mechanism for the reaction. Equation Transcription: Text Transcription: AlCl_3 CHCl_3 AlCl_3

Using resonance structures of the intermediates, explain why bromination of biphenyl occurs at ortho and para positions rather than at met.

Benzene and alkyl-substituted benzenes can be hydroxylated by reaction with \(\mathrm{H}_{2} \mathrm{O}_{2}\) in the presence of an acidic catalyst. What is the structure of the reactive electrophile? Propose a mechanism for the reaction. Equation Transcription: Text Transcription: H_2O_2 H_2O_2 CF_3SO_3H

Addition of HBr to 1-phenylpropene yields only (1-bromopropyl)benzene. Propose a mechanism for the reaction, and explain why none of the other regioisomer is produced. Equation Transcription: Text Transcription: HBr

Hexachlorophene, a substance used in the manufacture of germicidal soaps, is prepared by reaction of 2,4,5-trichlorophenol with formaldehyde in the presence of concentrated sulfuric acid. Propose a mechanism for the reaction. Equation Transcription: Text Transcription: CH_2O H_2SO_4 CH_2

Benzenediazonium carboxylate decomposes when heated to yield \(\mathrm{N}_{2}, \mathrm{CO}_{2}\), and a reactive substance that can’t be isolated. When benzenediazonium carboxylate is heated in the presence of furan, the following reaction is observed: What intermediate is involved in this reaction? Propose a mechanism for its formation. Equation Transcription: Text Transcription: N2, CO2 C-O N \equiv N CO2+N2

4-Chloropyridine undergoes reaction with dimethylamine to yield 4-dimethylaminopyridine. Propose a mechanism for the reaction. Equation Transcription: Text Transcription: HN(CH_3)_2 N(CH_3)_2+HCl

Propose a mechanism to account for the following reaction: Equation Transcription: Text Transcription: H_3C CH_2Cl AlCl_3 H_3C CH_3

In the Gatterman–Koch reaction, a formyl group ( - CHO) is introduced directly onto a benzene ring. For example, reaction of toluene with CO and HCl in the presence of mixed \(\mathrm{CuCl} / \mathrm{AlCl}_{3}\) gives p-methylbenzaldehyde. Propose a mechanism. Equation Transcription: Text Transcription: CuCl/AlCl_3 CH_3+CO+HCl CuCl/AlCl_3 CH_3 CHO

Treatment of p-tert-butylphenol with a strong acid such as \(\mathrm{H}_{2} \mathrm{SO}_{4}\) yields phenol and 2-methylpropene. Propose a mechanism. Equation Transcription: Text Transcription: H_2SO_4

Benzyl bromide is converted into benzaldehyde by heating in dimethyl sulfoxide. Propose a structure for the intermediate, and show the mechanisms of the two steps in the reaction. Equation Transcription: Text Transcription: CH_2Br H_3C-S+-CH_3 S_N2

Propose a mechanism for the Smiles rearrangement below. Equation Transcription: Text Transcription: H_2N NO_2 NO_2

Because of their conjugation, azo dyes are highly colored compounds and the major artiicial color source for textiles and food. Azo dyes are produced by the reaction of aryl diazonium salts with a second aromatic compound. In the product, the aromatic rings are linked by a diazo bridge \((-N=N-)\). From the reactants provided, propose a structure for each azo dye and draw the electron-pushing mechanism. Equation Transcription: Text Transcription: (-N=N-) NaO_3S Cl+N \equiv N NaO_3S OCH_3 Cl+N\equivN NaO_3S CH_3 CO_2Na CH_3 SO3N_a N \equiv N Cl

Identify each of the following groups as an activator or deactivator and as an o,p-director or m-director: Equation Transcription: Text Transcription: N(CH_3)_2 OCH_2CH_3

Predict the major product(s) of nitration of the following substances. Which react faster than benzene, and which slower? (a) Bromobenzene (b) Benzonitrile (c) Benzoic acid (d) Nitrobenzene (e) Benzenesulfonic acid (f) Methoxybenzene

Rank the compounds in each group according to their reactivity toward electrophilic substitution. (a) Chlorobenzene, o-dichlorobenzene, benzene (b) p-Bromonitrobenzene, nitrobenzene, phenol (c) Fluorobenzene, benzaldehyde, o-xylene (d) Benzonitrile, p-methylbenzonitrile, p-methoxybenzonitrile

Predict the major monoalkylation products you would expect to obtain from reaction of the following substances with chloromethane and \(\mathrm{AlCl}_{3}\): (a) Bromobenzene (b) m-Bromophenol (c) p-Chloroaniline (d) 2,4-Dichloronitrobenzene (e) 2,4-Dichlorophenol (f) Benzoic acid (g) p-Methylbenzenesulfonic acid (h) 2,5-Dibromotoluene Equation Transcription: Text Transcription: AlCl_3

Name and draw the major product(s) of electrophilic chlorination of the following compounds: (a) m-Nitrophenol (b) o-Xylene (c) p-Nitrobenzoic acid (d) p-Bromobenzenesulfonic acid

Predict the major product(s) you would obtain from sulfonation of the following compounds: (a) Fluorobenzene (b) m-Bromophenol (c) m-Dichlorobenzene (d) 2,4-Dibromophenol

Rank the following aromatic compounds in the expected order of their reactivity toward Friedel–Crafts alkylation. Which compounds are unreactive? (a) Bromobenzene (b) Toluene (c) Phenol (d) Aniline (e) Nitrobenzene (f) p-Bromotoluene

What product(s) would you expect to obtain from the following reactions? Equation Transcription: Text Transcription: CH_3 NO_2 H_2/Pd Br Br HNO_3H_2SO_4 Fe,H_3O+ KMnO_4 H_2O Cl OCH_3 CH_3CH_2CH_2Cl AlCl_3

Predict the major product(s) of the following reactions: Equation Transcription: Text Transcription: Cl CH_3CH_2Cl AlCl_3 CH_3CH_2COCl AlCl_3 CO_2H HNO_3 H_2SO_4 N(CH_2CH_3)_2 SO_3 H_2SO_4

How would you synthesize the following substances starting from benzene or phenol? Assume that ortho- and para-substitution products can be separated. (a) o-Bromobenzoic acid (b) p-Methoxytoluene (c) 2,4,6-Trinitrobenzoic acid (d) m-Bromoaniline

Starting with benzene as your only source of aromatic compounds, how would you synthesize the following substances? Assume that you can separate ortho and para isomers if necessary. (a) p-Chloroacetophenone (b) m-Bromonitrobenzene (c) o-Bromobenzenesulfonic acid (d) m-Chlorobenzenesulfonic acid

Starting with either benzene or toluene, how would you synthesize the following substances? Assume that ortho and para isomers can be separated. (a) 2-Bromo-4-nitrotoluene (b) 1,3,5-Trinitrobenzene (c) 2,4,6-Tribromoaniline (d) m-Fluorobenzoic acid

As written, the following syntheses have laws. What is wrong with each? Equation Transcription: Text Transcription: CH3 Cl2,FeCl3 KMnO4 CO2H HNO3,H2SO4 CH3Cl,AlCl3 Fe,H3O+ NaOH,H2O CH3 NH2 CH3 CH3Cl,AlCl3 HNO3,H2SO4 H2/Pd CH3 NO3 CH2CH3

At what position and on what ring do you expect nitration of 4-bromobiphenyl to occur? Explain, using resonance structures of the potential intermediates.

Electrophilic substitution on 3-phenylpropanenitrile occurs at the ortho and para positions, but reaction with 3-phenylpropenenitrile occurs at the meta position. Explain, using resonance structures of the intermediates. Equation Transcription: Text Transcription: CH_2CH_2CN

At what position, and on what ring, would you expect the following substances to undergo electrophilic substitution? Equation Transcription: Text Transcription: CH_3 Br CH_3

At what position, and on what ring, would you expect bromination of benz anilide to occur? Explain by drawing resonance structures of the intermediates.

Would you expect the Friedel–Crafts reaction of benzene with (R)-2- chlorobutane to yield optically active or racemic product? Explain.

How would you synthesize the following substances starting from benzene? Equation Transcription: Text Transcription: HOCH_2 CH_2OH CH_2CH_2OH

The compound MON-0585 is a nontoxic, biodegradable larvicide that is highly selective against mosquito larvae. Synthesize MON-0585 using either benzene or phenol as a source of the aromatic rings. Equation Transcription: Text Transcription: CH_3 CH_3 C(CH_3)_3 OH C(CH_3)_3

The compound MON-0585 is a nontoxic, biodegradable larvicide that is highly selective against mosquito larvae. Synthesize MON-0585 using either benzene or phenol as a source of the aromatic rings. Equation Transcription: Text Transcription: CH_3 CH_3 C(CH_3)_3 OH C(CH_3)_3

Draw resonance structures of the intermediate carbocations in the bromination of naphthalene, and account for the fact that naphthalene undergoes electrophilic substitution at C1 rather than C2. Equation Transcription: Text Transcription: Br_2 Br

Propose a mechanism for the reaction of 1-chloroanthraquinone with methoxide ion to give the substitution product 1-methoxyanthraquinone. Use curved arrows to show the electron low in each step. Equation Transcription: Text Transcription: Na+-OCH3 OCH3 NaCl

p-Bromotoluene reacts with potassium amide to give a mixture of m-and p-methylaniline. Explain.

Propose a mechanism to account for the reaction of benzene with 2,2,5,5-tetramethyltetrahydrofuran. Equation Transcription: Text Transcription: H_2SO_4

How would you synthesize the following compounds from benzene? Assume that ortho and para isomers can be separated. Equation Transcription: Text Transcription: O_2N CH_3 Br Cl CH_3 CH_2CHCH_3 SO_3H

You know the mechanism of HBr addition to alkenes, and you know the effects of various substituent groups on aromatic substitution. Use this knowledge to predict which of the following two alkenes reacts faster with HBr. Explain your answer by drawing resonance structures of the carbocation intermediates. Equation Transcription: Text Transcription: CH_3O CH=CH_2 O_2N CH=CH_2

Use your knowledge of directing effects, along with the following data, to deduce the directions of the dipole moments in aniline and bromobenzene. Equation Transcription: Text Transcription: NH_{2} Br Br NH_{2} \mu=1.53 D \mu=1.52 D \mu=2.91 D

Identify the reagents represented by the letters a–e in the following scheme: Equation Transcription: Text Transcription: Br Br Br Br

Phenols (ArOH) are relatively acidic, and the presence of a substituent group on the aromatic ring has a large effect. The \(p K_{a}\) of unsubstituted phenol, for example, is 9.89, while that of p-nitrophenol is 7.15. Draw resonance structures of the corresponding phenoxide anions and explain the data. Equation Transcription: Text Transcription: p K_{a}

Would you expect p-methylphenol to be more acidic or less acidic than unsubstituted phenol? Explain. (See Problem 16-75.)

Predict the product(s) for each reaction below. In each case, draw the resonance forms of the intermediate to explain the observed regiochemistry. Equation Transcription: Text Transcription: CH_3 HNO_3 H_2SO_4 CH_3 (CH_3)_2CHCl,AlCl_3 Cl_2,FeCl_3 CH_3O l_2,CuCl_2

Melamine, used as a fire retardant and a component of the writing surface of white boards, can be prepared from s-trichlorotriazine through a series of SNAr reactions with ammonia. The first substitution takes place rapidly at room temperature. The second substitution takes place near 100 °C, and the third substitution requires even higher temperature and pressure. Provide an explanation for this reactivity. Equation Transcription: Text Transcription: NH_3 NH_2 NH_2 H_2N