38.6 amperes of current is passed for 100 seconds through an aqueous $$\mathrm{CuSO}_4$$ solution using platinum electrodes. The mass of copper consumed from the solution and volume of gas liberated at STP are respectively (molar mass of $$\mathrm{Cu}=63.54 \mathrm{~g} \mathrm{~mol}^{-1}$$).

The reduction potential of hydrogen electrode at $$25^{\circ} \mathrm{C}$$ in a neutral solution is ($$p_{\mathrm{H}_2}=1$$ bar)

If hydrogen electrons dipped in two solutions of pH = 3 and pH = 6 are connected by a salt bridge, the emf of the resulting cell is

At $$291 \mathrm{~K}$$, saturated solution of $$\mathrm{BaSO}_4$$ was found to have a specific conductivity of $$3.648 \times 10^{-6} \mathrm{ohm}^{-1} \mathrm{~cm}^{-1}$$ and that of water being used is $$1.25 \times 10^{-6} \mathrm{ohm}^{-1} \mathrm{~cm}^{-1}$$. If the ionic conductances of $$\mathrm{Ba}^{2+}$$ and $$\mathrm{SO}_4^{2-}$$ are 110 and $$136.6 \mathrm{ohm}^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$$ respectively. The solubility of $$\mathrm{BaSO}_4$$ at $$291 \mathrm{~K}$$ will be [Atomic masses of $$\mathrm{Ba}=137, \mathrm{~S}=32, \mathrm{O}=16]$$