0.5 kg of methane is initially at 500 kPa and 25°C. The methane expands in an isothermal p...

0.5 kg of methane is initially at 500 kPa and 25°C. The methane expands in an isothermal process until its final volume is twice its initial volume. Assuming the methane behaves as an ideal gas with constant specific heats, determine

(a) the initial volume,

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(b) the final pressure,

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(c) the change in specific internal energy, and

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(d) the change in specific enthalpy of the methane.