A gas with initial conditions \(p_{\mathrm{i}}, V_{\mathrm{i}}\), and \(T_{\mathrm{i}}\) expands isothermally until \(V_{\mathrm{f}}=2 V_{\mathrm{i}}\). What are

(a) \(T_{\mathrm{f}}\) and

(b) \(p_{\mathrm{f}}\) ?