CHEM 201 Fall 2012

Name_____________________________

QUIZ 5, FORM A 20 minutes, SHOW YOUR WORK! KaKb = Kw = = 1.008×10!14 1. 35.0 mL of a 0.10 M aqueous solution of nitric acid, HNO3 (in flask) is titrated with 0.070 M NaOH (in buret). (1 pt)

(a) What is the reaction that takes place?

(1 pt)

(b) What, in addition to water, will be in the flask after the titration has been started, but before enough NaOH has been added to reach the equivalence point of the titration? (Don’t include things present in very small concentrations, for example, OH! in an acidic solution or H3O+ in a basic solution.)

(1 pt)

(c) How is the solution in the flask best characterized after the titration has been started, but before enough NaOH has been added to reach the equivalence point of the titration? (strong acid, weak acid, strong base, weak base, buffer, neutral)

(1 pt)

(d)

(1 pt)

(e) How is the solution in the flask best characterized at the equivalence point in the titration? (strong acid, weak acid, strong base, weak base, buffer, neutral)

(1 pt)

(f)

(1 pt)

(g) How is the solution in the flask best characterized past the equivalence point in the titration? (strong acid, weak acid, strong base, weak base, buffer, neutral)

(2 pt)

(h) How many mL’s of the NaOH solution needs to be added to reach the equivalence point of the titration?

What, in addition to water, will be in the flask at the equivalence point of the titration?

What, in addition to water, will be in the flask past the equivalence point of the titration?

CONTINUED ON BACKY

Quiz 5, Form A 1. Continuation of titration problem from the other side... 35.0 mL of a 0.10 M aqueous solution of nitric acid, HNO3 (in flask) is titrated with 0.070 M NaOH (in buret). (4 pt)

(i) What will be the pH of the solution in the flask after 52.0 mL of the NaOH solution has been added? (You need to know where this is relative to the equivalence point to answer this question correctly.)

2. Ksp of CaF2 is 3.2 × 10!11 (3 pt)

(a) What are the ionic dissolution reaction and the Ksp or ion-product expression for CaF2? (Could you answer this question correctly if I had given you the name instead of the formula? You don’t have to answer this...but on the upcoming exam I will be giving you the name instead of the formula on questions like this...and there will be questions like this, so make sure you still know the names, formulas and charges of the common ions.)

(4 pt) (b) Calculate the molar solubility of CaF2 in pure water from it’s Ksp.

CHEM 201 Fall 2012

Name_____________________________

QUIZ 5, FORM B 20 minutes, SHOW YOUR WORK! KaKb = Kw = 1.008×10!14 1. 35.0 mL of a 0.10 M aqueous solution of glycolic acid, CH2(OH)CO2H (in flask) is titrated with 0.070 M NaOH (in buret). Ka of glycolic acid, CH2(OH)CO2H = 1.5×10!4 (1 pt)

(a) What is the reaction that takes place?

(1 pt)

(b) What, in addition to water, will be in the flask after the titration has been started, but before enough NaOH has been added to reach the equivalence point of the titration? (Don’t include things present in very small concentrations, for example, OH! in an acidic solution or H3O+ in a basic solution.)

(1 pt)

(c) How is the solution in the flask best characterized after the titration has been started, but before enough NaOH has been added to reach the equivalence point of the titration? (strong acid, weak acid, strong base, weak base, buffer, neutral)

(1 pt)

(d)

(1 pt)

(e) How is the solution in the flask best characterized at the equivalence point in the titration? (strong acid, weak acid, strong base, weak base, buffer, neutral)

(1 pt)

(f)

(1 pt)

(g) How is the solution in the flask best characterized past the equivalence point in the titration? (strong acid, weak acid, strong base, weak base, buffer, neutral)

(2 pt)

(h) How many mL’s of the NaOH solution needs to be added to reach the equivalence point of the titration?

What, in addition to water, will be in the flask at the equivalence point of the titration?

What, in addition to water, will be in the flask past the equivalence point of the titration?

CONTINUED ON BACKY

Quiz 5, Form B 1. Continuation of titration problem from the other side... 35.0 mL of a 0.10 M aqueous solution of glycolic acid, CH2(OH)CO2H (in flask) is titrated with 0.070 M NaOH (in buret). Ka of glycolic acid, CH2(OH)CO2H = 1.5×10!4 (4 pt)

(i) What will be the pH of the solution in the flask after 30.0 mL of the NaOH solution has been added? (You need to know where this is relative to the equivalence point to answer this question correctly.)

2. Ksp of ZnCO3 is 1.0 × 10!10 (3 pt)

(a) What are the ionic dissolution reaction and the Ksp or ion-product expression for ZnCO3? (Could you answer this question correctly if I had given you the name instead of the formula? You don’t have to answer this...but on the upcoming exam I will be giving you the name instead of the formula on questions like this...and there will be questions like this, so make sure you still know the names, formulas and charges of the common ions.)

(4 pt)

(b) Calculate the molar solubility of ZnCO3 in pure water from it’s Ksp.

CHEM 201 Fall 2012

Name_____________________________

QUIZ 5, FORM C 20 minutes, SHOW YOUR WORK! KaKb = Kw = = 1.008×10!14 1. 35.0 mL of a 0.10 M aqueous solution of propylamine, CH3CH2CH2NH2 (in flask) is titrated with 0.070 M HBr (in buret). Kb of propylamine, CH3CH2CH2NH2 = 3.5×10!4 (1 pt)

(a) What is the reaction that takes place?

(1 pt)

(b) What, in addition to water, will be in the flask after the titration has been started, but before enough HBr has been added to reach the equivalence point of the titration? (Don’t include things present in very small concentrations, for example, OH

! in an acidic solution or H3O+ in a basic solution.)

(1 pt)

(c) How is the solution in the flask best characterized after the titration has been started, but before enough HBr has been added to reach the equivalence point of the titration? (strong acid, weak acid, strong base, weak base, buffer, neutral)

(1 pt)

(d) What, in addition to water, will be in the flask at the equivalence point of the titration?

(1 pt)

(e) How is the solution in the flask best characterized at the equivalence point in the titration? (strong acid, weak acid, strong base, weak base, buffer, neutral)

(1 pt)

(f) What, in addition to water, will be in the flask past the equivalence point of the titration?

(1 pt)

(g) How is the solution in the flask best characterized past the equivalence point in the titration? (strong acid, weak acid, strong base, weak base, buffer, neutral)

(2 pt)

(h) How many mL’s of the HBr solution needs to be added to reach the equivalence point of the titration?

CONTINUED ON BACKY

Quiz 5, Form C 1. Continuation of titration problem from the other side... 35.0 mL of a 0.10 M aqueous solution of propylamine, CH3CH2CH2NH2 (in flask) is titrated with 0.070 M HBr (in buret). Kb of propylamine, CH3CH2CH2NH2 = 3.5×10!4 (4 pt)

(i) What will be the pH of the solution in the flask after 52.0 mL of the HBr solution has been added? (You need to know where this is relative to the equivalence point to answer this question correctly.)

2. The molar solubility of Mg3(PO4)2 in water is 8.64 × 10!6 M. (3 pt)

(a) What are the ionic dissolution reaction and the Ksp or ion-product expression for Mg3(PO 4) 2 ? (Could you answer this question correctly if I had given you the name instead of the formula? You don’t have to answer this...but on the upcoming exam I will be giving you the name instead of the formula on questions like this...and there will be questions like this, so make sure you still know the names, formulas and charges of the common ions.)

(4 pt)

(b) Calculate the Ksp of Mg3(PO4)2 from its molar solubility.