Let's assume the gas is acting ideally, Then, applying Ideal Gas Equation, assuming number of moles constant,
P₁ V₁ / T₁ = P₂ V₂ / T₂ ------ (1)
Data:
P₁ = 100 kPa
P₂ = 90 kPa
V₁ = 2.50 L
V₂ = 3.75 L
T₁ = 303 K
T₂ = ?
Solving Eq. 1 for T₂,
T₂ = (P₂ × V₂ × T₁) × (P₁ × V₁)
Putting Values,
T₂ = (90 kPa × 3.75 L × 303 K) ÷ (100 kPa × 2.50 L)
T₂ = 409 K
