The electrical expenditure is five rupees to produce 4 grams of calcium from fused `CaSO_(4)`. What is the production cost of 2 grams of hydrogen produced electrically from acidulated water ?

Explanation

`Ca_((aq))^(2+)+2e^(-)rarr Ca_((s))` and `2H_((aq))^(+) + 2e^(-) rarr H_(2(g))`
2 Fardays are required to deposit 40g og Ca or to liberate 2g of hydrogen. As 4g of Ca production requires Rs 5/- , 20 g of Ca (Equivalent Weight) requires Rs 25. Therefore the cost of 1 Faraday electricity is Rs.25/- . For the production of 2g of `H_(2)`, 2 Faraday,s of electricity is required. Hence the cost of electricity for the production of 2g of `H_(2)` is Rs.50/-.