300 mL of a gas at $27°\text{C}$  is cooled to $-\text{3°C}$  at constant pressure; the final volume is

According to Charles’s law.

${\text{V}}_{\text{1}}=300\text{mL}$        ${\text{T}}_2=3°\text{C}$      

${\text{T}}_{\text{1}}=27°\text{C}$          ${\text{V}}_2=?$         

 ${\text{T}}_1=27+273=300\text{K}$ ; ${\text{T}}_2=-\text{3}+\text{273}=\text{270K}$

Apply Charles’s law equation for a gas at different conditions.

           $\frac{{\text{V}}_{\text{1}}}{{\text{T}}_1}=\frac{{\text{V}}_{\text{2}}}{{\text{T}}_{\text{2}}}$

$\Rightarrow {\text{V}}_{\text{2}}=\frac{{\text{V}}_{\text{1}}}{{\text{T}}_{\text{1}}}\times {\text{T}}_2=\frac{\cancel{300}\times 270}{\cancel{300}}$

  $\therefore \text{Fianl}{\text{volume,V}}_{\text{2}}=270\text{mL}$