Question

Choose the correct expression of $K_p$ for reaction,
$4N{H}_3\left(g\right)+5O_2\left(g\right)\rightleftharpoons 4NO\left(g\right)+6H_{2}O\left(g\right)$

• A. $K_p=\frac{\left[P_{NO}{]}^4\right[P_{H_{2}O}{]}^6}{\left[P_{N{H}_3}{]}^4\right[P_{O_2}{]}^5}$
• B. $K_p=\frac{\left[P_{N{H}_3}{]}^4\right[P_{O_2}{]}^5}{\left[P_{NO}{]}^4\right[P_{H_{2}O}{]}^6}$
• C. $K_p=\frac{\left[P_{N{H}_3}\right]\left[P_{O_2}\right]}{\left[P_{NO}\right]\left[P_{H_{2}O}\right]}$
• D. $K_p=\frac{\left[P_{NO}\right]\left[P_{H_{2}O}\right]}{\left[P_{N{H}_3}\right]\left[P_{O_2}\right]}$

Answer 1

The correct option is A $K_p=\frac{\left[P_{NO}{]}^4\right[P_{H_{2}O}{]}^6}{\left[P_{N{H}_3}{]}^4\right[P_{O_2}{]}^5}$

The equilibrium constant of the reaction, $K_p$, is the ratio of the equilibrium partial pressure of products over the equilibrium partial pressure of reactants each raised to the power of their stoichiometric coefficients.
Thus, for reaction
$4N{H}_3\left(g\right)+5O_2\left(g\right)\rightleftharpoons 4NO\left(g\right)+6H_{2}O\left(g\right)$

$K_p=\frac{\left[NO{]}^4\right[H_{2}O{]}^6}{\left[N{H}_3{]}^4\right[O_2{]}^5}$