Answer:
91.4°C
Step-by-step explanation:
Gay - Lussac Law => T ∝ P => T = kP => k = T/P with volume (V) and mass (n) constant.
For two different Temperature (T)-Pressure (P) conditions
k₁ = k₂ => T₁/P₁ = T₂/P₂ => T₂ = T₁(P₂/P₁)
T₁ = 55°C = (55 + 273)K = 328K
P₁ = 965 mmHg
T₂ = ?
P₂ = 850 mmHg
T₂ = T₁(P₂/P₁) = 328K(850 mmHg/965 mmHg) = 364K = (364 - 273)°C = 91.4°C