Question

Write the expression for the equilibrium constant Kp for the following reaction.Enclose pressures in parentheses and do NOT write the chemical formula as a subscript. For example, enter (PNH3)2 as (P NH3)2 .If either the numerator or denominator is 1, please enter 1NH4HS(s) ↔ NH3(g) + H2S(g)

Answer 1

Answer: The expression for $K_p$ is written below.

Explanation:

Equilibrium constant in terms of partial pressure is defined as the ratio of partial pressures of the products and the reactants each raised to the power their stoichiometric ratios. It is expressed as $K_p$

For a general chemical reaction:

$aA+bB\rightleftharpoons cC+dD$

The expression for $K_p$ is written as:

$K_p=\frac{P_{C}^c\times P_{D}^d}{P_{A}^a\times P_{B}^b}$

The partial pressure for solids and liquids are taken as 1.

For the given chemical equation:

$NH_4HS(s)\rightleftharpoons NH_3(g)+H_2S(g)$

The expression for $K_p$ for the following equation is:

$K_p=\frac{(P NH_3)\times (P H_2S)}{(P NH_4HS)}$

The partial pressure of $NH_4HS$ will be 1 because it is solid.

So, the expression for $K_p$ now becomes:

$K_p=\frac{(P NH_3)\times (P H_2S)}{1}$

Hence, the expression for $K_p$ is written above.