One mole of an ideal gas expands isothermally and reversibly at `25^(@)C` from a volume of `10` litres to a volume of `20` litres.
(i) What is the change in entropy of the gas?
(ii) How much work is done by the gas?
(iii) What is `q` (surroundings) ?
(iv) What is the change in the entropy of the surroundings?
(v) What is the change in the entropy of the system plus the surroundings ?

Explanation

To solve the problem, we will follow these steps:

### Given Data:
- Number of moles (n) = 1 mole
- Initial volume (V1) = 10 L
- Final volume (V2) = 20 L
- Temperature (T) = 25°C = 298 K
- Universal gas constant (R) = 8.314 J/(mol·K)
...