Sodium sulfate 10-hydrate, \(\mathrm{Na}_{2} \mathrm{SO}_{4} \cdot 10
\mathrm{H}_{2} \mathrm{O},\) dehydrates according to the equation
\(\mathrm{Na}_{2} \mathrm{SO}_{4} \cdot 10 \mathrm{H}_{2} \mathrm{O}(s)
\rightleftharpoons \mathrm{Na}_{2} \mathrm{SO}_{4}(s)+10 \mathrm{H}_{2}
\mathrm{O}(g) \quad K_{P}=4.08 \times 10^{-25} \mathrm{at} 25^{\circ}
\mathrm{C}\)
What is the pressure of water vapor at equilibrium with a mixture of
\(\mathrm{Na}_{2} \mathrm{SO}_{4} \cdot 10 \mathrm{H}_{2} \mathrm{O}\) and
\(\mathrm{NaSO}_{4} ?\)