Chemistry, 15.07.2019 08:30 jasramos004

Find and report the reduction potentials of lithium, sodium, and potassium.

Answers: 1

Show answers

Answers

The electrode potential values of ${\text{L}}{{\text{i}}^ + }$ , ${\text{N}}{{\text{a}}^ + }$ and ${{\text{K}}^ + }$ are $\boxed{ - 3.045{\text{ V}}}$ , $\boxed{ - {\text{2}}{\text{.714 V}}}$ and $\boxed{ - {\text{2}}{\text{.925 V}}}$ respectively.

Further explanation:

Electrochemical cells are the devices that are used to generate an electric current from the energy released by the spontaneous redox reaction. Redox reactions involve the transfer of electrons between the chemical species by oxidation and reduction process. The oxidation process represents the loss of electrons and reduction process represents the gain of electrons.

In order to determine the standard reduction potential, the electrode is coupled with standard hydrogen electrode as illustrated in the attached image. The SHE acts as anode and the metal electrode acts as the cathode. The value of reduction potential for hydrogen has been assigned as 0.00 V.

The formula to calculate cell potential $\left( {{E_{{\text{cell}}}}} \right)$ of the reaction when the reduction occurs as cathode and oxidation occur at anode is as follows:

${E_{{\text{cell}}}} = {E_{{\text{cathode}}}} - {E_{{\text{anode}}}}$

The expression of Nernst equation that relates the reduction potential of a half or full electrochemical cell reaction to the standard electrode potential is given as,

${E_{{\text{cell}}}} = E_{{\text{cell}}}^\circ - \dfrac{{2.303RT}}{{nF}}\log \dfrac{{\left[ P \right]}}{{\left[ R \right]}}$ ……. (1)

Here,

${E_{{\text{cell}}}}$ is cell potential.

$E_{{\text{cell}}}^\circ$ is standard cell potential.

is gas constant and is equal to $8.314{\text{ J/K}} \cdot {\text{mol}}$ .

is temperature.

denotes the number of moles of electrons transferred in the reaction.

is Faraday constant and is equal to $95484.56{\text{ C/mol}}$ .

$\left[ P \right]$ is the concentration of product.

$\left[ R \right]$ is the concentration of reactant.

At standard temperature $25\;^\circ {\text{C}}\left( {298{\text{ K}}} \right)$ the value of $\dfrac{{2.303RT}}{F}$ is equal to $0.0592{\text{ V}}$ . Thus the equation(1) is written as,

${E_{{\text{cell}}}} = E_{{\text{cell}}}^\circ - \dfrac{{0.0591}}{n}\log \dfrac{{\left[ P \right]}}{{\left[ R \right]}}$ …… (2)

Knowing the concentration of the electrolyte solutions taken in the cathodic compartment and substituting the values in the Nernst equation gives the reduction potential for the half cell.

The electrode potential values of ${\mathbf{L}}{{\mathbf{i}}^{\mathbf{ + }}}$ , ${\mathbf{N}}{{\mathbf{a}}^{\mathbf{ + }}}$ and ${{\mathbf{K}}^{\mathbf{ + }}}$ are ${\mathbf{ - 3}}{\mathbf{.045 V}}$ , ${\mathbf{ - 2}}{\mathbf{.714 V}}$ and ${\mathbf{ - 2}}{\mathbf{.925 V}}$ respectively as determined with respect to standard hydrogen electrode at ${\mathbf{298 K}}$ .

Learn more:

1. Effectiveness of detergent: link

2. Scientific notation: link

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Electrochemistry

Keywords: Electrochemical cells, Redox reactions, Oxidation, reduction, cell potential, half-cell, Nernst equation and Faraday constant.

Answer from: Quest

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.

Answer from: Quest

the objects have the same charge is correct.

nathan lee

Another question on Chemistry

Chemistry, 22.06.2019 21:30

Plzz a sample of table sugar (sucrose, c12h22o11) has a mass of 7.801 g. ● a) calculate the number of moles of c12h22o11 in the sample b) calculate the number of moles of each element in c12h22o11 (number of moles of c, number of moles of h & number of moles of o) in the sample. (use your answer from part a as your starting point.) show your work and highlight your final answer. calculate the number of atoms of each element in c12h22o11 (number of atoms of c, number of atoms of h & number of atoms of o) in the sample. (use your answers from part b as your starting for each element.) show your work and highlight your final answer.

Answers: 1

Answer

Chemistry, 22.06.2019 23:00

What is the oxidation state of each individual carbon atom in c2o42−?

Answers: 1

Answer

Chemistry, 23.06.2019 00:00

What is the empirical formula of a compound that is 50.7% antimony and 49.3% selenium ?

Answers: 2

Answer

Chemistry, 23.06.2019 01:30

Astudent states that 9.0 g of baking soda will form an unsaturated solution in 100 g of water. what do you need to know to decide whether this statement is correct? a. the temperature of the water and the molar mass of baking soda b. the percent by volume of the solution and the solubility of baking soda c. the temperature of the water and the solubility of baking soda at that temperature

Answers: 1

Answer

You know the right answer?

Find and report the reduction potentials of lithium, sodium, and potassium....

Questions