In the electrolytic refining of copper, an impure copper block (containing Zn, Fe, Ag and Au) is the anode, a thin pure copper sheet is the cathode and the electrolyte is acidified $CuSO X_{4}$ . Which statement is incorrect?

A $Zn$ and $Fe$ from the anode pass into the solution as $Zn X^{2 +}$ and $Fe X^{2 +}$
B $Ag$ and $Au$ are deposited on the cathode along with copper
CThe concentration of $Cu X^{2 +}$ in the electrolyte remains nearly constant during the process
DThe anode loses mass and the cathode gains mass

Answer: B

Metals more active than copper (Zn, Fe) are oxidised at the anode and stay in solution because

Cu X^{2 +}

is reduced in preference to them at the cathode. Metals less active than copper (Ag, Au) are not oxidised at the anode potential and fall off as anode mud; they never reach the cathode. For every

Cu X^{2 +}

deposited at the cathode one

Cu

dissolves at the anode, so

[Cu X^{2 +}]

is nearly constant. Statement (B) is incorrect.

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In the electrolytic refining of copper, an impure copper block (containing Zn, Fe, Ag and Au) is the anode, a thin pure copper sheet is the cathode and the electrolyte is acidified CuSOX4​. Which statement is incorrect?

Answer: B

More questions on Electrolysis and products at electrodes

In the electrolytic refining of copper, an impure copper block (containing Zn, Fe, Ag and Au) is the anode, a thin pure copper sheet is the cathode and the electrolyte is acidified $CuSO X_{4}$ . Which statement is incorrect?