An effusion cell has a circular hole of diameter $1.50 \mathrm{~mm}$. If the molar mass of the solid in the cell is $300 \mathrm{~g} \mathrm{~mol}^{-1}$ and its vapour pressure is $0.735 \mathrm{~Pa}$ at $500 \mathrm{~K}$, by how much will the mass of the solid decrease in a period of $1.00 \mathrm{~h}$ ?
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