CHEM 102: Study Guide
Chapters: 18, 12, 16.7-8
Sorry it’s late y’all. Also, I’m never making them multiple choice again unless y’all want me to lose any semblance of sanity while making these. Good Luck and email me if you want or need help or something is wrong with the study guide. Chemical Equilibrium (Chapter 12)
1. Kc= [Concentration of products to the power of the
coefficient]/[Concentration of reactants to the power of the coefficient] 2. Kp = Kc(RT)Δn
3. Kp= the rate constant for the pressure of each reaction,
4. ∆n=moles of gaseous products – moles of gaseous reactants 5. When a Solid or Pure Liquid are in the reaction, do not include them in the expression for the equilibrium constant.
6. Reaction Quotients
1. Qc= substituting the initial concentrations of reactants
and products into the Kc expression
2. Qc<Kc, system proceeds left to right
3. Qc=Kc, EQUILIBRIUM
4. Qc>Kc, to the left, to the left, to the left
7. Rice Tables
1. In a vertical line, write RICE or ICE
2. Write the BALANCED EQUATION, next to the R,
(reaction, this step is optional, but you can’t forget to
balance the reaction), if you didn’t write R, just write it
above where you want everything
3. Next to the I, underneath each element or compound,
write the INITIAL concentration,
4. Next to the C, (change), write the change of each
compound in terms of x multiplied by the coefficient and
the direction of the reaction.
a. If the reaction is proceeding from LEFT TO RIGHT,
then the REACTANTS ARE NEGATIVE, and the
PRODUCTS ARE POSITIVE
b. If the reaction is proceeding from RIGHT TO LEFT,
then the REACTANTS ARE POSITIVE, and the
PRODUCTS ARE NEGATIVE
5. Next to the E, (equilibrium), write the initial We also discuss several other topics like bus 2110 class notes
concentration combined with the change, I+( ± C)
6. Given Kc, (or calculated), solve for x through foiling out
and simplifying. QUADRATIC FORMULA IS BACK. Y’all mfs
remember this, X=(-b±√(b2-4ac))/2a
7. USE THE X FROM STEP 6, plug back into the E step and
there ya go, equilibrium concentrations,
8. Le Chateliers Principle Don't forget about the age old question of damien salamone
a. Moves away from stress.
i. Some Examples and Rules
1. If some reactant is ADDED: Moves to products
2. If some reactant is REMOVED: Moves to reactants
3. If some product is ADDED: Moves to reactants
4. If some product is REMOVED: Moves to products
ii. Changes in Volume and Pressure: can only affect gaseous species
1. If the PRESSURE is INCREASED: Moves to side with
2. If the PRESSURE is DECREASED: Moves to side with most moles Don't forget about the age old question of gluconeogenesis bypass steps
3. If the VOLUME is INCREASED: Moves to side with most
4. If the VOLUME is DECREASED: Moves to side with fewest moles
iii. Change in Temperature
1. Increase in Temperature
a. Exothermic rxn. = K decreases
b. Endothermic rxn. = K increases
2. Decrease in Temperature
a. Exothermic rxn. = K increases
b. Endothermic rxn. = K decreases
iv. Adding a catalyst DOES NOT EFFECT EQUILIBRIUM OR K b.
1. In a closed, one-liter reaction chamber, nitrosyl bromide (NOBr) decays into nitrogen monoxide and bromine. The K-value of the reaction is determined
to be 0.42. After 0.9 moles of NOBr is added, calculate the equilibrium concentration of bromine.
2. In an 8.5 L chamber, carbon dioxide gas is reacted with hydrogen gas to create carbon monoxide and water. With a K-value of 0.802, calculate the equilibrium concentration of carbon monoxide if 34 moles of both carbon dioxide and hydrogen gas is added. We also discuss several other topics like cedarville moodle
3. In a reaction between hydrogen gas and iodine gas, the equilibrium concentration of hydrogen iodide is determined to be 0.63 M. determine the K value of the reaction if the initial molarity of hydrogen gas is 0.7 M and the initial molarity of iodine gas is 0.4 M.
4. In a closed chamber, the reaction ����2(����) + ������2(����) ⇌ ����������(����) + ��������(����) goes to equilibrium. After it goes to equilibrium, some BrOCl is added. What way will the equilibrium shift?
5. A sealed 5 L reaction chamber has 20 moles of carbon monoxide, 8 moles of nitrogen monoxide, and 30 moles of carbon dioxide. As the K value is 8.11, determine the concentration of nitrogen dioxide at equilibrium.
6. Iron (III) oxide and hydrogen react to form iron and water. In a 6.2 L reaction vessel, 3.35 grams of iron (III) oxide, 4.07 grams of hydrogen gas, 5.75 grams of iron metal, and 3.95 grams of gaseous water are found at equilibrium. Calculate the equilibrium constant for the reaction. Don't forget about the age old question of bus 2110 study guide
7. ����3����2����2(����) + ������(����) → ����−(����) + ����3����2����3+(����) The equilibrium constant for this reaction at 298 degrees Kelvin is calculated to be 8.22. If 0.4 M of ����3����2����2and 0.7 M of HCl are in the chamber initially, calculate the concentration of dissociated chlorine at equilibrium.
8. Calculate the Kp of ����4����(2) ⇌ ��2��(��) + ����3(��) given the Kc is 0.77 at 31 degrees Celsius.
9. For the reaction ��2(��) + 3��2(��) ⇌ 2����3(��), write the pressure equilibrium constant expression.
Nuclear Chemistry (Chapter 18)
1. Types of radioactive particles
a. Alpha particles (α): a helium nuclei,
b. Beta particles (β): electrons, positive or negatively charged c. Gamma rays (γ): Particles unaffected by magnetic fields, aka high energy photons, leaves in a ray.
d. Positron (β+), a positively charged electron
2. Positron-Electron Collision: When a positron collides with an electron, 2 gamma-ray photons are created, traveling in two directions. This is because positrons are antimatter which when colliding with normal matter cancels out. This releases a ton of energy We also discuss several other topics like chm 1025 final exam with answers
3. Electron Capture: The nucleus captures an electron, converting a proton to a neutron, (reverse of beta decay)
4. Positron Emission: A proton decays into a neutron, positron, and a neutrino.
5. Alpha Decay: An alpha particle is ejected from the nucleus. 6. Beta Decay: A beta particle and an antineutrino are emitted from the nucleus.
7. All radioactive decay follows first order kinetics
1. The half-life of carbon-14 to nitrogen-14 is 5730 years (5.73 x 103years). A nuclear chemical analysis reveals that there is 0.623 mmol of nitrogen-14 for every 1.000 mmol of carbon-14 in a sample. Calculate the age of the rock to two sig figs.
2. The activity due to the radioactive decay of carbon-14 from a wooden artifact is measured to be 43. Bq. The activity from a piece of fresh wood of a similar size is 59 Bq. Given the half-life of carbon-14 being 5.73 x 103 years, calculate the age of the artifact to two significant figures.
Gibbs, Spontaneity, and Entropy (Chapter 16.7-8)
1. Given the reaction, ��2(��) + 3��2(��) ⇌ 2����3(��), calculate the equilibrium constant at 25 degrees Celsius. [∆G values; NH3=-16.4 kJ/mol]
2. Given an equilibrium constant of a reaction equaling 2.37, calculate the ∆G of a reaction at 212 degrees Celsius.
1. 0.25 M
2. 1.89 M
4. Reactants, Left
5. 1.39 M
7. 0.35 M
8. Kp=4.92 x 106
1. 4.0 x 103years
2. 6.0 x 103years
1. K= 1.79 x 10-6
2. ∆G=3.48 x 103kJ/mol