4.5g of aluminium (at. mass 27 amu) is deposited at cathode from Al3+ solution by a certain quantity of electric charge. The volume of hydrogen produced at STP from H+ ions in solution by the same quantity of electric charge will be :

To solve this problem, we need to understand the relationship between the amount of substance deposited during electrolysis and the amount of electric charge used. The deposition of aluminium from Al3+ ions involves the transfer of 3 electrons per ion. The production of hydrogen from H+ ions involves the transfer of 1 electron per ion. Given that 4.5g of aluminium is deposited, we can calculate the number of moles of aluminium deposited using its atomic mass (27 g/mol). Then, knowing that each mole of aluminium requires 3 moles of electrons for deposition, we can calculate the total charge used. With this charge, we can then calculate the number of moles of hydrogen produced (since 1 mole of electrons produces 1 mole of hydrogen), and finally, the volume of hydrogen at STP (1 mole of an ideal gas occupies 22.4 L at STP). So, the steps involve calculating the moles of aluminium deposited, determining the charge used, calculating the moles of hydrogen produced with that charge, and then finding the volume of hydrogen at STP.