Chemistry - Chemical Equilibrium Question with Solution | TestHub

For the reaction $A\cdot 3H_{2}O(s)\rightleftharpoons A(s)+3H_{2}O(g)$, $K_P=5.12\times 10^{-7}at{m}^3$ at $27^{\circ }C$.

The equilibrium partial pressure of water vapor, $P_{H_{2}O}$, is found from $K_P=(P_{H_{2}O}{)}^3$.

$P_{H_{2}O}=(5.12\times 10^{-7}{)}^{1/3}=0.008atm$.

Relative humidity (RH) = $(P_{H_{2}O}/P_{H_{2}O}^{\circ })\times 100\%$.

Given $P_{H_{2}O}^{\circ }=0.04atm$.

RH = $(0.008/0.04)\times 100\%=20\%$.