Question

One mole of an ideal gas is expanded isothermally and reversibly to half of its initial pressure. ΔS for the process in JK⁻¹ mol⁻¹ is ______.

[ln 2 = 0.693 and R = 8.314, J/(mol K)]

Options

• 6.76

• 5.76

• 10.76

• 8.03

Answer 1

One mole of an ideal gas is expanded isothermally and reversibly to half of its initial pressure. ΔS for the process in JK⁻¹ mol⁻¹ is 5.76.

Explanation:

For the isothermal process (ΔT = 0)

ΔS = `"R" ln "P"_1/"P"_2`

= 8.314 ln 2

= 8.314 × 0.693

= 5.76