Question

A gas system has an unknown pressure and an initial temperature of 299K. When the temperature is increased to 620 K the pressure is measured at 7.77 atm. The volume is constant throughout. What was the initial pressure in atm?

Answer 1

3.75 atm

Explanation:

Volume remains constant, so we can use Gay-Lussac’s Law.

p₁/T₁ = p₂/T₂ Multiply both sides by T₁

p₁ = p₂ × T₁/T₂

p₁ = ?; T₁ = 299 K

p₂ = 7.77 atm; T₂ = 620 K Insert the values

p₁ = 7.77 × 299/620 Do the operations

p₁ = 3.75 atm