Chemistry, 23.07.2019 14:00 jahnoibenjamin

Aconcentration cell consists of two sn/sn2 half-cells. the cell has a potential of 0.18 v at 25 ? c. part a what is the ratio of the sn2 concentrations in the two half-cells?

Answers: 1

Show answers

Answers

Answer from: azaz1819

One half cell is a cathode and other is an anode.
The electrodes in both half cells are same as Sn.

Anodic reaction;
Sn(s) → Sn²⁺(aq) + 2e E⁰oxi = +0.137 V

Cathodic reaction;
Sn²⁺(aq) + 2e → Sn(s) E⁰red= -0.137 V

E⁰cell = E⁰red - E⁰oxi
E⁰cell = 0 V

TheNernst equation;
Ecell = E⁰cell - (RT/nF) ln[anode] / [cathode]

Ecell = 0.18 V
E⁰cell = 0 V
R = 8.314 J mol⁻¹ K⁻¹
T = 298 K
n = 2 mol (electrone moles that participated in)
F = 96485 C mol⁻¹ (Fara¹day constan)

By applying Nernst equation;
0.18 = 0 - ((8.314 x 298) / (2 x 96485)) ln [anode]/[cathode]
0.18 = 0 - 2.303 x 0.0128 log₁₀ [anode]/[cathode]
0.18 = 0 - 0.0295 log₁₀ [anode]/[cathode]
0.2095 = log₁₀ [anode]/[cathode]
[anode]/[cathode] = antilog 0.2095
= 1.62.

Hence Sn²⁺ concentration ration in two half cells = 1.62

Answer from: Quest

Cis your correct answer

Answer from: Quest

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form( $n_2$ ) .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.