Question

For the reaction, A(g) ⇋ 2B(g), Kc=7.0K. A reaction mixture at equilibrium contains [A] = 4.2M. What is the concentration of B in the reaction mixture?

Answer 1

The concentration of B in the reaction mixture is approximately 5.42 M.

The equilibrium constant is the ratio of the concentrations of the products raised to their coefficients divided by the concentrations of the reactants raised to their coefficients. This expression helps quantify the extent of a chemical reaction at equilibrium.

The equilibrium constant for the reaction
`\(A(g) \rightleftharpoons 2B(g)\)` is given as 7.0 at a certain temperature.

The expression for
`\(K_c\)` this reaction is:

`\[ K_c = ([B]^2)/([A]) \]`

Given that [A] = 4.2 M, we can rearrange the equation to solve for [B]:

`\[ [B]^2 = K_c * [A] \]`

`\[ [B] = √(K_c * [A]) \]`

Substituting the values:

`\[ [B] = √(7.0 * 4.2) \]`

`\[ [B] \approx √(29.4) \]`

`\[ [B] \approx 5.42 \, \text{M} \]`

Therefore, the concentration of B in the reaction mixture is approximately 5.42 M.