When 50 J of heat is supplied to an ideal gas, it expands from 100 cm ^3 to 200 cm ^3 at a constant pressure of 2.0 10^5 Pa . Calculate the change in internal energy of the gas.

Step-by-step solution

Given heat supplied to the gas, Q = 50 J . Initial volume, V₁ = 100 cm ^3 = 100 10⁻⁶ m ^3 . Final volume, V₂ = 200 cm ^3 = 200 10⁻⁶ m ^3 . Constant pressure, P = 2.0 10^5 Pa . Work done by the gas is given by: W = P(V₂ - V₁) W = 2.0 10^5 (200 - 100) 10⁻⁶ J W = 2.0 10^5 10⁻⁴ J = 20 J According to the first law of thermodynamics: Q = U + W U = Q - W U = 50 J - 20 J = 30 J