Neco 2021 Chemistry Question 20

Practice objective / multiple choice question 20 from the 2021 Neco Chemistry examination.

Neco 2021 Chemistry Objective / Multiple Choice Medium Difficulty
Question 20 NECO • 2021 • CHEMISTRY • objective

An electrochemical cell consists of a Zn electrode in 1.0 M ZnSO4 and a Cu electrode in a Cu^{2+} solution of unknown concentration. Standard potentials: \(E^\circ_{\text{Cu}^{2+}/\text{Cu}} = +0.34\ \text{V}\), \(E^\circ_{\text{Zn}^{2+}/\text{Zn}} = -0.76\ \text{V}\).\n(a) If the measured cell potential at 25 °C is 1.05 V, calculate the concentration of Cu^{2+} in the solution.\n(b) Using this concentration, determine the mass of copper deposited when a current of 0.500 A is passed for 30.0 min (100 % current efficiency).

Answer Options

A. [Cu^{2+}] = 1.0×10^{-2}\\ \text{M}; mass of Cu = 0.15\\ \text{g}
B. [Cu^{2+}] = 2.0×10^{-3}\\ \text{M}; mass of Cu = 0.03\\ \text{g}
C. [Cu^{2+}] = 5.0×10^{-2}\\ \text{M}; mass of Cu = 0.75\\ \text{g}
Correct Answer D. [Cu^{2+}] = 2.0×10^{-2}\ \text{M}; mass of Cu = 0.30\ \text{g}
Correct Answer
D
Correct Option:
[Cu^{2+}] = 2.0×10^{-2}\ \text{M}; mass of Cu = 0.30\ \text{g}

About This Question

This is Neco 2021 Chemistry Question 20. It is one of the objective questions from the 2021 Neco Chemistry examination.

Difficulty level: Medium .

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