Chapter U6, Problem SI5RE

(a)

Interpretation Introduction

Interpretation :

The equilibrium equation for the reaction of hydrogen and iodine to produce HI must be written.

Concept Introduction :

Equilibrium constant is the ratio of concentration of products to the concentration of reactants.

Answer to Problem SI5RE

The equilibrium reaction is given below.

$\text{K=}\frac{{\text{[HI]}}^{\text{2}}}{{\text{[H}}_{\text{2}}{\text{][I}}_{\text{2}}\text{]}}$ .

Explanation of Solution

When hydrogen is reacted with iodine, then HI is the product. The coefficient is raised to the power of concentration. As the coefficient of HI is 2, so there is ${\left[\text{HI}\right]}^{\text{2}}$ in the product. The coefficient of H₂ and I₂ is 1. So, there is 1 power of both [H₂] and [I₂].

Thus, the expression of equilibrium constant (K) is given.

b)

Interpretation Introduction

Interpretation :

Equilibrium concentration of HI must be found out.

Concept Introduction :

Equilibrium concentration can be found out from the given (equilibrium constant) K value and equilibrium concentrations of other species.

Answer to Problem SI5RE

The equilibrium concentration of HI is 0.74.

Explanation of Solution

The equilibrium concentration of HI can be calculated as follows:

 $\begin{array}{c}\text{55=}\frac{{\text{[HI]}}^{\text{2}}}{\text{[0}\text{.10][0}\text{.10]}}\end{array}$

$\begin{array}{c}{\text{[HI]}}^{\text{2}}\text{=55×0}\text{.10×0}\text{.10}\end{array}$

  $\begin{array}{c}\text{=0}\text{.55}\end{array}$

$\begin{array}{c}\text{[HI]=}\sqrt{\text{0}\text{.55}}\end{array}$

  $\begin{array}{c}\text{=0}\text{.74}\end{array}$

c)

Interpretation Introduction

Interpretation :

On observing an equilibrium mixture of these compounds, if one would expect to see more reactants, products or an equal amount of both, must be explained.

Concept Introduction :

The value of the equilibrium constant gives an idea of how much reactant is converted to the product. When the equilibrium constant has a high value, then the maximum reactant is converted to product.

Answer to Problem SI5RE

The reaction mixture will contain more products, i.e., HI.

Explanation of Solution

The equilibrium constant is 55. So, the ratio of the concentration of HI to the product of concentrations of H₂ and I₂ is 55. So,the concentration of HI is 55 times to the concentration of reactants. Thus, in the reaction, the product has more concentration than the reactant.