Solutions and Equilibrium Review

1

100

Calculate the final concentration of the solution when 25.0 mL of a 0.200 M NaBr solution is diluted to 50.0 mL. 

0.100 M

200

Calculate the freezing point of a solution where 0.580 mol of lactose, a nonelectrolyte, is added to 1.0 kg of water. 

-1.08^o C

300

Write the equilibrium expression for: 

CH₄ (g) + 2O₂ (g) <--> CO₂ (g) + 2H₂O (g) 

[CO₂][H₂O]²

[CH][O₂]²

400

Calculate K_eq for the reaction if the concentrations at equilibrium are 0.20 M NH₃, 3.0 M N_2, 0.50 M H₂. 

2NH₃(g) <--> N₂ (g) + 3H₂ (g) 

K = 9.4

500

For each of the following changes at equilibrium, indicate whether the equilibrium shifts in the direction of the products, reactants, or does not change 

C₂H₄(g) + Cl₂(g) ⇋ C₂H₄Cl₂(g) + heat 

a. Increase Temperature

b. Decrease Volume 

c. Add more Cl₂

a. Reactants 

b. Products

c. Products

1

100

Write the equilibrium expression for: 

C(s) + 2H₂(g) ⇋ CH₄(g) 

[CH₄]

[H₂]²

200

Calculate the final concentration of the solution when 25.0 mL of a 0.200 M NaBr solution is diluted to 50.0 mL 

0.100 M NaBr

300

Write the chemical equation for the dissociation of BaF₂. 

BaF₂ (s) --> Ba²⁺ (aq) + 2F^- (aq) 

400

Will iodine (I₂) dissolve in H₂O? 

No - IMFs don't match. 

500

For each of the following changes at equilibrium, indicate whether the equilibrium shifts in the direction of products, reactants, or no shift. 

N₂ (g) + O₂ (g) + heat <--> 2NO(g) 

a. Increase Temperature 

b. Decrease Volume 

c. Adding more N₂ 

a. products 

b. no change 

c. products

2

100

The Kc for the following reaction is 5.0 at 100 °C. If an equilibrium mixture contains 0.50 M NO₂, what is the concentration of N₂O₄? 

2NO₂(g) ⇋ N₂O₄(g) 

1.3 M

200

Write the net ionic equation for this reaction: 

AgNO₃ (aq) + LiCl (aq) --> AgCl (s) + LiNO₃ (aq)

Ag⁺ (aq) + Cl^- (aq) --> AgCl (s)

300

Calculate the freezing point of a solution of 111 g KCl_, a strong electrolyte, dissolved in 1.00 kg of water. 

-5^o C

400

Calculate the final concentration of the solution when 25.0 mL of a 0.200 M NaBr solution is diluted to 50.0 mL .

0.100 M NaBr

500

Which of the following stresses would cause the equilibrium to shift towards the right (products) for the following reaction? 

2NH₃ (g) <---> 3H₂ (g) + N₂ (g) 

a. Adding H₂

b. Removing N₂

c. Increasing Volume

d. Decreasing Volume

b, c 

3

100

How many mols of each of the following strong electrolytes are needed to give the same freezing point lowering as 1.2 mol of the nonelectrolyte ethylene glycol in 1 kg of water? 

a. NaCl

b. K₃PO₄

a. 0.6 M NaCl 

b. 0.3 M K₃PO₄

200

The K is 2.0 for this reaction: 

2NOBr (g) <--> 2NO (g) + Br₂ (g) 

In an experiment, 1.0 mol of NOBr, 1.0 mol NO, and 1.0 mol Br₂ were placed in a 1.0-L container. 

Is this system at equilibrium?

No, equilibrium expression is not equal to K, so not at equilibrium. 

300

Consider the reversible reaction A + C <--> B. If 3.0 M A is mixed with 2.0 M C and no B, what would be the relative rates of the forward and reverse reactions at time = 0?

Very fast forward reaction, no reverse reaction 

400

A solution is prepared with 70.0 g of HNO₃ and 130.0 g of H₂O. The HNO₃ solution has a density of 1.21 g/mL. What is the molarity of the solution?

6.73 M HNO₃

500

Indicate if you would increase or decrease the volume of the container to increase the yield of the products for: 

2C(s) + O₂ (g) <--> 2CO (g) 

Increase