a) Calculate the heat that must be supplied to 1 mole of air to maintain its temperature at 298 K if the gas is expanded isothermally and reversibly from a volume of 25 dm3 to 35 dm3.

b) Calculate the work done by the system w when one mole of zinc is dissolved in hydrochloric acid: Zn (s) + 2HCl (aq) = ZnCl2 (aq) + H2 (g) Assume that the ambient pressure is 1 bar and the temperature is 298 K. (Hint: use ideal gas law and take care with the sign of your answer.)