Exam review problems

write the expression for Kc for the reaction: CO2(g) + CaO(s) ⇌ CaCO3(s)

(CaCO3) / (CO2) (CaO)

A student dissolved 4.00 g of Co(NO3)2 in enough water to make 100. mL of stock solution. What is the molarity of the NO3- ion in the final solution?

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11 a. Write the equilibrium constant expression Kc for the reaction (all are gases). CO+ 3H2 →CH4 + H2O If Kc = 221 and at equilibrium [CH4] = 11M, [H20] = 13M and [H2] = 0.88M, what is the equilibrium concentration of [CO]?

0.949

In the following reaction HCO3 (aq) + NH3(aq) ⇌ CO3 2- (aq) + NH4+ (aq) a. HCO3- is an acid and NH3 is its conjugate base. b. HCO3 is an acid and CO32- is its conjugate base. c.NH3 is an acid and HCO32- is its conjugate base. d.NH3 is an acid and NH4+ is its conjugate base. e.NH4+ is an acid and CO32- is its conjugate base.

B) HCO3 is an acid and CO32- is its conjugate base.

Which one of the following compounds is insoluble in water? A) CaCl2 B) NaNO3 C) PbCl2 D) K2CO3 E) None of the above is insoluble

C) PbCl2

Assuming the compound completely dissociates, what is the pH of a 0.007 M Mg(OH)2 solution? a. 1.85 b. 2.15 c. 11.85 d.12.15 e. not enough information to tell

C. 11.85

Explain what happens to the equilibrium of the following reaction when additional CH4 is added to a system already at equilibrium? What concept did you use to answer the question? CO+3H2<--→CH4 +H2O

Move to the reactants. Le Chatelier's Principle.

a. What is the volume % (v/v) benzene of a 350. mL solution that contains 84 mL of C6H6 (benzene)? b. What is the molarity of a solution that contains 84 g of C6H6 in 0.50 L of solution?

a) 24 % b) 2.14

A) How many grams of CaSO4 are in 250 mL of a 1.35 M solution of CaSO4? Part B) If 11.5 mL of 1.35 M CaSO4 is diluted to 250 mL, what is the concentration of the new solution? Part C) What volume of 1.3 M Ca SO4 is needed to prepare 45 g of Ba SO4 ? Ca SO4 (aq) + Ba(NO3)2 (aq) → Ba SO4 (s) + Ca(NO3)2 (aq)

a) 45.94 b) 0.0621 c) 0.14 L

Which of the following pairs of aqueous solutions will form a precipitate when mixed? A) NH4NO3 + Li2CO3 B) AgNO3 + LiCI C) NaCl + Li3PO4 D) AgC2H3O2 + Cu(NO3)2 E) None of the above solution pairs will produce a precipitate.

b) AgNO3 + LiCl

All of the following are weak acids EXCEPT a. HF b. HBr c. HC2H3O2 d. NH4+ e. HCN

b) HBr

Which of the following chemical reactions corresponds to the acid ionization constant, Ka, for hydrogen carbonate ion (HCO3-)? a. HCO3-(aq) + OH- (aq) ⇌ CO32- (aq) + H2O (l) b. HCO3- (aq) + H3O+ (aq) ⇌ H2CO3(aq) + H2O (l) c. HCO3- (aq) + H20 (l) ⇌ CO32- (aq) + H3O(aq) d. HCO3- (aq) ⇌ CO2(g) + OH- (aq) e. HCO3-(aq) + H3O+ (aq) ⇌ CO2(g) + 2H2O (l)

c. HCO3- (aq) + H20 (l) ⇌ CO32- (aq) + H3O(aq)

What 3 conditions are required for a chemical reaction to occur?

collision, orientation, and energy.

According to the Brønsted-Lowry definition, a base a. increases the H3O+ concentration in a solution. b.increases the OH- concentration in a solution. c. is a proton donor. d. is a proton acceptor. e. has a lone pair of electrons that can bond to a proton.

d) Is a proton acceptor

Which of the following weak acids is the strongest? a. hydrocyanic acid, Ka = 4.0 x 10^-10 b. benzoic acid, Ka = 6.3 x 10^-5 c. dihydrogen phosphate ion, Ka = 6.2 x 10^-8 d. formic acid, Ka = 1.8 x 10^-4 e. acetic acid, Ka = 1.8 x 10^-5

d. formic acid, Ka = 1.8 x 10^-4