Heat supplied to 0.5 mol of a monoatomic ideal gas at constant pressure is 500 J. Initial temperature is 27°C. Find ΔU and ΔT. Use R≈8.33 J mol⁻¹ K⁻¹.
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Heat supplied to 0.5 mol of a monoatomic ideal gas at constant pressure is 500 J. Initial temperature is 27°C. Find ΔU and ΔT. Use R≈8.33 J mol⁻¹ K⁻¹.

G1 Physics · Accepted Answer

At constant pressure Q=n C p Δ T C_pΔT C p ​ Δ T with C p = 5 R / 2. C_p=5R/2. C p ​ = 5 R /2. Thus 500=0.5×(5R/2)ΔT, giving ΔT≈48 K. For a monoatomic gas, ΔU=n C v Δ T C_vΔT C v ​ Δ T with C v = 3 R / 2 , C_v=3R/2, C v ​ = 3 R /2 , so ΔU=(3/5)Q=300 J.