A current of 48.25 A is passed for 1000 s through a solution of a zinc salt, where each Zn ion gains 2 electrons. What mass of zinc is deposited? (F = 96500 C/mol; molar mass 65 g/mol)
Answer and explanation
Correct answer: A. 16.25 g
- Step 1: Charge Q = It = 48.25 × 1000 = 48250 C, which is 0.5 mol of electrons. Step 2. Moles of metal = 0.5 ÷ 2, so mass = 16.25 g. Answer: 16.25 g. Why not the others: 32.5 g is what you get if you forget to divide by the electrons per ion. 8.125 g is what you get if you divide by the electrons twice. 162.5 g is what you get if you misplace a power of ten.
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