Practicing Success
A solution of \(CuSO_4\) is electrolyzed for \(10\, \ min\) with a currecnt of \(1.5 A\). What is the mass of copper deposited at the cathode (molar mass of \(Cu = 63 g\)) (\(1F = 96487C\)) |
2.93 g 3.4 g 1.9 g 0.2938 g |
0.2938 g |
The correct answer is option 4. 0.2938 g. Given, Time \((t) = 10\, \ min = 600 s\) Current \((I) = 1.5 A\) The reaction of cathode can be formulated as: \(Cu^{2+} + 2e^- \longrightarrow Cu(s)\) Thus, 2 electrons are transferred here. Mass of \(Cu = 63\, \ g mol^{-1}\) We know that, \(Charge\, \ =\, \ time \, \ × \, \ current\) \(⇒ Charge\, \ = 600 × 1.5 = 900C\) Now, mass of copper deposited \(= \frac{\text{Molar mass } × \text{ Charge}}{\text{electrons transferred } × \text{ Faraday's constant}}\) \(= \frac{63 × 900}{2 × 96487}\) \(= \frac{56700}{192974}\) \(= 0.2938 g\) |