# 10.4.1: Practice Equilibrium Constants

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Exercise $$\PageIndex{1}$$

$3 H_{2 (g)} + N_{2 (g)} \longleftrightarrow 2 NH_{3 (g)}$

What is the equilibrium constant expression of the reaction above?

$$K_{eq} = \dfrac{[NH_{3}]^{2}}{[H_{2}]^{3}[N_{2}]}$$

Exercise $$\PageIndex{1}$$

$2 SO_{2 (g)} + O_{2 (g)} \longleftrightarrow 2 SO_{3 (g)}$

The Keq of the reaction above is 3.4 x 102.  Is the equilibrium mixture mostly SO2 and O2 or mostly SO3?

mostly SO3

Exercise $$\PageIndex{1}$$

$C_{(s)} + 2 S_{(g)} \longleftrightarrow CS_{2 (g)}$

What is the equilibrium constant expression of the reaction above?

$$K_{eq} = \dfrac{[CS_{2}]}{[S]^{2}}$$

Exercise $$\PageIndex{1}$$

$Pb^{2+}_{(aq)} + 2 Cl^{1–}_{(aq)} \longleftrightarrow PbCl_{2 (s)}$

What is the equilibrium constant expression of the reaction above?

$$K_{eq} = \dfrac{1}{[Pb^{2+}][Cl^{1–}]^{2}}$$