/
Electrochemistry Concepts
Save to my account
Sign up
Electrochemistry Concepts
Electrochemistry Concepts
Study
1
Question
What is electrochemistry?
Answer
Electrochemistry is the study of the production of electricity from energy released during spontaneous chemical reactions and the use of electrical energy to bring about non-spontaneous chemical transformations.
2
Question
What are galvanic cells?
Answer
Galvanic cells are electrochemical cells that convert the chemical energy of a spontaneous redox reaction into electrical energy.
3
Question
What is the Nernst equation used for?
Answer
The Nernst equation is used for calculating the emf (electromotive force) of a galvanic cell.
4
Question
Define standard potential of a cell.
Answer
Standard potential of a cell is the electrode potential when the concentrations of all the species involved in a half-cell are unity.
5
Question
What happens in a Daniell cell during a redox reaction?
Answer
In a Daniell cell, the redox reaction Zn(s) + Cu^2+(aq) → Zn^2+(aq) + Cu(s) converts chemical energy into electrical energy.
6
Question
What is the standard hydrogen electrode?
Answer
The standard hydrogen electrode (SHE) is an electrode consisting of a platinum surface in contact with H2 gas at 1 bar pressure and a solution of H+ ions at 1 M concentration, assigned a potential of 0 V.
7
Question
What is the role of the anode and cathode in a galvanic cell?
Answer
In a galvanic cell, the anode is the half-cell where oxidation occurs and has a negative potential, while the cathode is where reduction occurs and has a positive potential.
8
Question
What is the significance of electrode potential?
Answer
Electrode potential is the potential difference developed between an electrode and the electrolyte, which indicates the tendency of the electrode to gain or lose electrons.
9
Question
What is the cell potential in a galvanic cell?
Answer
The cell potential is the difference between the electrode potentials of the cathode and anode, measured in volts.
10
Question
What does a positive standard electrode potential indicate?
Answer
A positive standard electrode potential indicates that the reduced form of the species is more stable compared to hydrogen gas.
11
Question
What is Kohlrausch's law?
Answer
Kohlrausch's law states that the conductivity of an electrolyte solution at infinite dilution is equal to the sum of the contributions of its individual ions.
12
Question
How does temperature affect the Nernst equation?
Answer
The Nernst equation includes temperature as a variable; specifically, it involves the gas constant R and temperature T, indicating that the electrode potential varies with temperature.
13
Question
What is the overall reaction in a Daniell cell?
Answer
The overall reaction in a Daniell cell is Zn(s) + Cu^2+(aq) → Zn^2+(aq) + Cu(s).
14
Question
What determines the direction of electron flow in a galvanic cell?
Answer
In a galvanic cell, electrons flow from the anode (negative electrode) to the cathode (positive electrode).
15
Question
What is the significance of the salt bridge in a galvanic cell?
Answer
The salt bridge allows for the conduction of ions between the two half-cells while preventing the mixing of different electrolytes, maintaining electrical neutrality.
16
Question
What are primary and secondary batteries?
Answer
Primary batteries are non-rechargeable, while secondary batteries are rechargeable and can be used multiple times.
17
Question
What is corrosion in the context of electrochemistry?
Answer
Corrosion is an electrochemical process involving the deterioration of metals due to reactions with their environment, often involving oxidation.
18
Question
What does the term 'molar conductivity' refer to?
Answer
Molar conductivity refers to the conductivity of an electrolyte solution divided by the molarity of the solution.
19
Question
What is the relationship between standard electrode potentials and oxidizing/reducing agents?
Answer
Standard electrode potentials indicate the strength of oxidizing and reducing agents; higher potentials correspond to stronger oxidizing agents and lower potentials to stronger reducing agents.
20
Question
What is the relationship between Gibbs energy and cell potential?
Answer
The Gibbs energy change of a cell reaction is related to the cell potential; a positive cell potential indicates a spontaneous reaction (negative Gibbs energy change).
21
Question
What is the formula for the cell potential in a galvanic cell?
Answer
The cell potential E_cell is given by the equation E_cell = E_right - E_left, where E_right is the potential of the cathode and E_left is the potential of the anode.
22
Question
What does the Nernst equation account for?
Answer
The Nernst equation accounts for the effect of concentration on the electrode potential, allowing for calculation of potential under non-standard conditions.
23
Question
What is the significance of the Faraday constant in electrochemistry?
Answer
The Faraday constant represents the charge of one mole of electrons, essential for calculating the amount of substance that reacts at an electrode during electrochemical processes.
24
Question
What do standard electrode potentials indicate about fluoride and lithium?
Answer
Fluoride has the highest standard electrode potential, indicating it is the strongest oxidizing agent, while lithium has the lowest potential, indicating it is the weakest oxidizing agent.
25
Question
How can standard electrode potentials be used in practice?
Answer
Standard electrode potentials are used to predict the feasibility of redox reactions and to determine the strength of oxidizing and reducing agents.
26
Question
What does E mean in the context of electrochemistry?
Answer
E means that the redox couple is a weaker reducing agent than the H2 couple.
27
Question
What is the electrochemical cell reaction for a Daniell cell?
Answer
For Cathode: E = E° + (RT/nF) ln([Cu2+]/[Cu]); For Anode: E = E° + (RT/nF) ln([Zn2+]/[Zn]).
28
Question
What is the cell potential equation for the Daniell cell?
Answer
The cell potential, E_cell = E_Cu2+/Cu + E_Zn2+/Zn.
29
Question
How does the cell potential E depend on the concentrations of Cu2+ and Zn2+ ions?
Answer
E increases with an increase in the concentration of Cu2+ ions and decreases with a decrease in the concentration of Zn2+ ions.
30
Question
What is the simplified form of the equation for E when the natural logarithm is converted to base 10?
Answer
E_cell = E° - (0.059/n) log([Zn2+]/[Cu2+]).