Answer
$348\ \mathrm{K}$
Work Step by Step
If the gas with fixed number of molecules has constant pressure, then
$\displaystyle \frac{\mathrm{V}_{\mathrm{i}}}{\mathrm{T}_{\mathrm{i}}}=\frac{\mathrm{V}_{\mathrm{f}}}{\mathrm{T}_{\mathrm{f}}}\qquad(17-8).$
The volume of a cylinder with base radius r and height h is
$\mathrm{V}= \pi r^{2}h$
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Solve 17-8 for $\mathrm{T}_{\mathrm{f}}$
$T_{\mathrm{f}}=\displaystyle \frac{V_{\mathrm{f}}T_{\mathrm{i}}}{V_{\mathrm{i}}}==\frac{\pi r^{2}h_{\mathrm{f}}T_{\mathrm{i}}}{\pi r^{2}h_{1}}=\frac{h_{\mathrm{f}}T_{\mathrm{i}}}{h_{1}}$
$=\displaystyle \frac{(26.0\ \mathrm{c}\mathrm{m})(313\ \mathrm{K})}{23.4\ \mathrm{c}\mathrm{m}}=348\ \mathrm{K}$
