Answer to Question #177081 in General Chemistry for dsafd

Question

X(g) + 2 Q(g) ⇄ R(g) + Z(g)  Kc = 1.3 × 10^-5 at 50°C

A 1.0 mol sample of X(g) and a 1.0 mol sample of Q(g) are introduced into an evacuated, rigid 10.0 L container and allowed to reach equilibrium at 50°C according to the equation above. At equilibrium, which of the following is true about the concentrations of the gases? EXPLAIN

• [Q] = 1/2[X]

• [R] = [Z] > [Q]

• [X] = [Q] = [R] = [Z]

•  [R] < [X]

2 S(s) + 2 O₂(g) ⇄ 2 SO₂(g)    K₁ = 2 x 10¹⁰⁵

2 SO₂(g) + O₂(g) ⇄ 2 SO₃(g)    K₂ = 7 x 10^-24

Given the value of the equilibrium constants K₁ and K₂ for the reactions represented above, what is the value of the equilibrium constant, K₃, for the following reaction? EXPLAIN

2 S(s) + 3 O₂(g) ⇄ 2 SO₃(g)    K₃ = ?

• 1 x 10⁸²

• 1 x 10⁴⁰

• 1 x 10⁶⁵

• 1 x 10¹³⁰

Answer 1

I) At equilibrium,

[R]<[X]

This is true because the equilibrium constant K_c which is 1.3x10^-5 is low. This means that at equilibrium, the concentration of products are relatively small compared to the concentration of reactants or more appropriately, the equilibrium position lies towards the left side of the reaction.

II) since the two equations are added up, the corresponding equilibrium constants will be multiplied.

K₃=K₁K₂

K₃= 2x10¹⁰⁵x7x10^-24

K₃= 14x10^105-24

K₃= 14x10⁸¹

K3= 1.4x10⁸²

So we can see from the answer that the closest option is

1x10⁸²