An amount of 19 g of molten is electrolysed for some time. Inert electrodes are used. 1.19 g of tin — Electrochemistry Chemistry Question
Question
An amount of 19 g of molten $SnCl_2$ is electrolysed for some time. Inert electrodes are used. 1.19 g of tin is deposited at the cathode. No substance is lost during electrolysis. If the ratio of the masses of $SnCl_2$ and $SnCl_4$ after electrolysis is $261:x$, the value of $x$ is ($Sn = 119$)
💡 Solution & Explanation
Initial moles of $SnCl_2$ (Molar mass = 190) = $19 / 190 = 0.1$ mol. Moles of Sn deposited = $1.19 / 119 = 0.01$ mol. The electrolysis of 0.01 mol $SnCl_2$ produces 0.01 mol $Cl_2$. Since no substance is lost, this $Cl_2$ reacts with the remaining $SnCl_2$ to form $SnCl_4$: $SnCl_2 + Cl_2 \rightarrow SnCl_4$. Moles of $SnCl_4$ formed = 0.01 mol, which consumes another 0.01 mol $SnCl_2$. Total $SnCl_2$ consumed = $0.01 + 0.01 = 0.02$ mol. Remaining $SnCl_2 = 0.1 - 0.02 = 0.08$ mol. Mass of remaining $SnCl_2 = 0.08 \times 190 = 15.2$ g. Mass of $SnCl_4$ (Molar mass = 261) = $0.01 \times 261 = 2.61$ g. Ratio = $15.2 / 2.61 = 1520 / 261$. Thus, the ratio $261 : x$ implies $x = 1520$. Therefore, correct answer is 1520.