Question

Write the equilibrium constant expression for the following reaction in terms of concentrations of the components. (Concentration equilibrium expressions take the general form: Kc = [C]c / [A]a . [B]b. Subscripts and superscripts that include letters must be enclosed in braces {}.) MgCO3(s) equilibrium reaction arrow MgO(s) + CO2(g)

Answer 1

Answer: The expression for equilibrium constant in terms of concentration is $K_c=[CO_2]$

Explanation:

Equilibrium constant in terms of concentration is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric coefficients. It is represented by $K_{c}$

For a general chemical reaction:

$aA+bB\rightarrow cC+dD$

The $K_{c}$ is written as:

$K_{c}=\frac{[C]^c[D]^d}{[A]^a[B]^b}$

The concentration of pure solids and pure liquids are taken as 1.

For the given chemical reaction:

$MgCO_3(s)\rightarrow MgO(s)+CO_2(g)$

The expression for $K_{c}$ is:

$K_{c}=\frac{[MgO][CO_2]}{[MgCO_3]}$

In the above expression, magnesium oxide and magnesium carbonate will not appear because they are present in solid state.

So, the expression for $K_c$ becomes:

$K_{c}=[CO_2]$

Hence, the equilibrium constant for the reaction is given above.