Can someone please help me with these problems and see if I got them correct?

Question

For the reaction BaSO₃ (s) ↔ BaO (s) + SO₂ (g), the equilibrium constant is 0.345 M. What is the concentration of SO₂ at equilibrium?

A. 0.035 M

B. 0.070 M

C. 0.280 M

D. 0.345 M

E. 0.520 M

For the reaction 2NOBr (g) ↔ 2NO (g) + Br₂ (g), when the concentrations are [NOBr] = 0.10 M, [NO] = 0.010 M, and [Br₂] = 0.0050 M, what is the equilibrium constant of this reaction?

A. 5.0 × 10–5 M

B. 0.0000005 M

C. 5.0 × 105 M

D. 5.0 M

E. None of the Above

 In the reaction SO₂ (g) + H₂O (l) ↔ H₂SO₃ (aq), with K = 2.1 × 10^–3, the concentration of SO₂ is 0.35 M, and the concentration of H₂SO₃ is 0.23 M. This reaction _______.

A. is in equilibrium

B. must shift to the reactants to be in equilibrium

C. must have the temperature increased to be in equilibrium

D. must have the pressure increased to reach equilibrium

E. None of the Above

 

Answer 1

For others who may be looking at this, I will show the calculations instead of just telling you if you are correct or not.

Keq = [SO₂] = 0.345 M so D would be the answer. In Keq expressions we do not include solids or liquids

Keq = [NO]²[Br₂] / [NOBr]²

Keq = (0.01)²(0.005) / (0.1)² = (0.0001)(0.005) / (0.01)

Keq = 5x10^-5 so A would be the answer

Solve for Q, the reaction quotient:

Q = [H₂SO₃] / [SO₂] = 0.23 / 0.35

Q = 0.66

Comparing this to the Keq of 2.1x10^-3, we see that is is greater than Keq. This tells us the system is past equilibrium, i.e. is too far right, so it must shift to the left or to reactants. So A would be the answer.