The final temperature :T₂=411.125 K = 138.125 °C
Further explanation
Given
T₁=-20 °C+273 = 253 K
V₁=40 ml
V₂=65 ml
Required
Final temperature
Solution
Charles's Law
When the gas pressure is kept constant, the gas volume is proportional to the temperature
Input the value :
T₂=(V₂.T₁)/V₁
T₂=(65.253)/40
T₂=411.125 K = 138.125 °C