The standard emf for the cell using the overall cell reaction below is +0.48 V: Zn(s) + Ni²⁺ (aq) → Zn²⁺ (aq) + Ni(s)
The emf generated by the cell when [Ni²⁺] = 2.50 mol L^-1 and [Zn²⁺] = 0.100 mol L^-1 is

Question

The standard emf for the cell using the overall cell reaction below is +0.48 V: Zn(s) + Ni<sup>2+</sup> (aq) → Zn<sup>2+</sup> (aq) + Ni(s) The emf generated by the cell when [Ni<sup>2+</sup>] = 2.50 mol L<sup>-1</sup> and [Zn<sup>2+</sup>] = 0.100 mol L<sup>-1</sup> is A) 0.40 B) 0.50 C) 0.52 D) 0.56 E) 0.44

Quizplus · Accepted Answer

To solve this problem, we can use the Nernst equation:

E = E° - (RT/nF) * ln(Q)

Where E° is the standard emf (0.48 V), R is the gas constant, T is the temperature (assumed to be 25°C), n is the number of electrons transferred in the reaction (2 in this case), F is the Faraday constant, and Q is the reaction quotient.

The reaction quotient can be written as:

Q = ([Ni2+] / [Zn2+]) = (2.50 mol/L) / (0.100 mol/L) = 25

Plugging in the values, we get:

E = 0.48 V - [(8.314 J/K/mol) / (2 * 96485 C/mol) * ln(25)] 
E ≈ 0.52 V

Therefore, the answer is (C) 0.52.

The Standard Emf for the Cell Using the Overall Cell