Explanation:

Given \(\mathrm{T_{1}=300 K, T_{2}=273 K(S T P)}\)
\({{\rm{V}}_{\rm{1}}}{\rm{ = 300ml = }}\left( {\frac{{{\rm{300}}}}{{{\rm{1000}}}}} \right){\rm{litre,}}\)
\({{\rm{P}}_{\rm{1}}}{\rm{ = }}\left( {\frac{{{\rm{730}}}}{{{\rm{760}}}}} \right){\rm{atm}} \cdot {{\rm{P}}_{\rm{2}}}{\rm{ = 1\;atm \times ,}}\,{{\rm{V}}_{\rm{2}}}{\rm{ = ?}}\)
\(\mathrm{\dfrac{P_{1} V_{1}}{T_{1}}=\dfrac{P_{2} V_{2}}{T_{2}}}\)
\(\mathrm{\dfrac{730 \times 300}{760 \times 1000 \times 300}=\dfrac{1 \times V_{2}}{273}}\)
\(\mathrm{\therefore \quad V_{2}=0.2622}\) litre \(\mathrm{=262.2 \mathrm{~mL}}\).