Question

$300$ ml of a gas at ${27}^o$C is cooled to $-8^o$C at constant pressure. The final volume is :

• A. $150$ ml
• B. $300$ ml
• C. $265$ ml
• D. $380$ ml

Answer 1

The correct option is C $265$ ml

$PV=nRT$
$V\propto T$
$V{T}^{\prime }=V^{\prime }T$ at constant pressure for a fixed amount of gas.
Initial volume V $=$ 300 ml.
Initial temperature T $=$ 27 ${}^o$ C $=27+273$ K $=$ 300 K
Final volume V' $=$ ??.
Final temperature T' $=-$ 8 ${}^o$ C $=273-8$ K $=$ 265 K.
$\text{300 mL}\times \text{265 K}=V^{\prime }\times \text{300}$
$V^{\prime }=\text{265 ml}$
Hence, the final volume is 265 ml.