Question

 

1) Consider the following equation: Rate = k [CH₃I]² [C₁₅H₁₁N]

i) If the concentration of C₁₅H₁₁N is doubled, does the rate constant:

A) Increase

B) Decrease

C) Remain unchanged

ii) If the concentration of of CH₃I is decreased by a factor of 3, the time it takes for the reaction to finish will:

A) Increase by a factor of 3

B) Increase by a factor of 9

C) Decrease by a factor of 9

D) Remain Unchanged

iii) If the temperature increases how will the activation energy change:

A) It will increase

B) It will decrease

C) It will remain unchanged

2) During a titration of a weak acid with a strong base you add an additional small amount of base after reaching the equivalence point.

i) How does the pH of the solution change?

A) Increase

B) Decrease

C) Remain unchanged

ii) How does the K_a of the acid change?

A) Increase

B) Decrease

C) Remain unchanged

3) You combine a solution of silver nitrate (AgNO₃) and a solution of sodium carbonate (Na₂CO₃) to form solid silver carbonate (Ag₂CO₃) and aqueous sodium nitrate (NaNO₃), the net ionic equation is listed below. You observe the white solid, Ag₂CO₃ in the test tube. You add a strong acid (HNO₃) to the mixture and it reacts with the carbonate ions as listed in the equations below. What would you expect to observe when adding the strong acid to the test tube?

2 Ag⁺_(aq) + CO₃^2-_(aq) <--> Ag₂CO_3(s)

2 H⁺_(aq) + CO₃^2-(aq) <--> H₂CO₃

H₂CO₃ -> H₂O_(l) + CO_2(g)

A) An increase in the amount of white solid

B) A color change of the solid

C) A decrease in the amount of white solid

D) No change in the amount of white solid

4) K_sp of BaF₂ at room temperature is 1.84 x 10^-7. It is also known that the reaction of dissolution of BaF₂ is endothermic. Imagine that you have a saturated solution of BaF₂ at equilibrium, that has some undissolved BaF₂ precipitated on the bottom of the test tube.

4.1) If the temperature is increased how would that affect:

i) The solubility of BaF₂

A) Increase

B) Decrease

C) Remain Unchanged

ii) The solubility constant of BaF₂

A) Increase

B) Decrease

C) Remain unchanged

4.2 An additional amount of BaF₂ was added to the solution how would that affect:

i) The solubility of BaF₂

A) Increase

B) Decrease

C) Remain unchanged

ii) The solubility constant of BaF₂

A) Increase

B) Decrease

C) Remain unchanged

4.3 If NaF is added to the solution how will it affect:

i) The solubility of BaF₂

A) Increase

B) Decrease

C) Remain Unchanged

ii) The solubility constant of BaF₂

A) Increase

B) Decrease

C) Remain unchanged

Answer 1

1]

i) Remains unchanged

Rate constant doesnt depend on the concentration of rectants

Rate changes which is depends on concetration of reactants

Answer is C

ii) Rate is inversely proportional to time

Since decreased by 3 times

the time for the reaction will increases by 9 times

Answer is B

iii) Temperature increases The Activation erngy will decrease

Answer is B

2]

i) pH increases

Answer is A

ii) Ka is constant

So it remains unchanged

Answer is C

3]

2 Ag+(aq) + CO32-(aq) <--> Ag2CO3(s)

Due H+ reaction with CO3-2 the amount of CO3-2 decreases this leads to reverse reaction

that means Ag2CO3 converts into Co3-2 and Ag+ to maintian equilibrium

So white solid decreases

Answer is C