Answer :
Final answer:
The student's chemistry question concerns calculating the heat (q) and work (W) for an ideal gas undergoing isothermal expansion. Since the heat absorbed is 208 J, the value of q is +208 J, and the work done by the gas on the surroundings is -208 J. Thus, the answer is C. +208,−208.
Explanation:
The student is asking about the thermodynamic quantities involved when an ideal gas undergoes isothermal expansion. To determine the values of heat (q) and work (W), we use the first law of thermodynamics, which states that the change in internal energy (ΔU) of a system is equal to the heat added to the system minus the work done by the system. However, in an isothermal process for an ideal gas, ΔU is zero.
Therefore, q = W but with opposite signs since heat added to the system results in positive work being done by the system. Given that the gas absorbs 208 J of heat, q would be +208 J. The gas does work on its surroundings as it expands, so W would be -208 J.
This is because the work done by a gas during expansion is considered positive from the surroundings' perspective but negative from the system's perspective. Therefore, the correct answer would be C. +208,−208.
