Calculate the voltage of a standard cell with the following half-cell reactions

In summary, the conversation involves calculating the voltage of a standard cell using two half-cell reactions and the electrolysis of water to produce oxygen. The first part involves using Hess' law and the stoichiometric ratio of electrons to solve for the voltage. The second part requires converting 11.2L of oxygen at STP to moles and using Faraday's Laws of Electrolysis to determine the required charge and time when a current of 0.5A is used. Helpful hints are provided for solving the problems and it is recommended to read up on the subject or use Google for further information.
  • #1
BH20
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0
1. I have to calculate the voltage of a standard cell with the following half-cell reactions:

Ni(s) ---> Ni2+ + 2e-
2e- + Cl2(g) ---> 2Cl-

2. By the electrolysis of water, 11.2L of oxygen at STP was prepared
a) What charge was required?
b) If a current of 0.5A was used, how long did it take?

Thanks for the help.
 
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  • #2
what do you need help for? these are all standard questions, it doesn't get any easier then this. Try solving it yourself first, show your work.
 
  • #3
these questions may very well be easy for you..but I am not familiar with calculating voltage and charge.

I don't need the answer, just a helpful hint. (a site, or something..I don't mind doing the work but I don't see any useful info about it in my book)
 
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  • #4
I'm sure your text talks about Faraday's Laws of Electrolysis. If not :eek:, there's always Google.
 
  • #5
hint #1

finding the voltage of the standard cell is similar to Hess' law (with the emphasis on "similar"). Perhaps you can remember the method now. What can you do with each of the standard emf values for each half reaction to solve the problem? The question is especially easy since the stoichiometric ratio of electrons are the same.

hint #2

2. By the electrolysis of water, 11.2L of oxygen at STP was prepared
a) What charge was required?
b) If a current of 0.5A was used, how long did it take?

It is quite important that you read up on this subject, it should be at the end of the electrolysis section of your text. First, what can yo do with the 11.2L at STP, how can yo convert this to moles?
 

1. What is a standard cell?

A standard cell is an electrochemical cell that is used as a reference for measuring the voltage of other cells. It consists of two half-cells, each with an electrode and an electrolyte solution, connected by a salt bridge.

2. What are half-cell reactions?

Half-cell reactions are the individual redox reactions that occur at the two electrodes in an electrochemical cell. They involve the transfer of electrons between the electrode and the electrolyte solution.

3. How do you calculate the voltage of a standard cell?

The voltage of a standard cell can be calculated using the Nernst equation, which takes into account the concentrations of the species involved in the half-cell reactions, as well as the temperature and the standard potential of the cell.

4. What is the purpose of a salt bridge in a standard cell?

A salt bridge is used to complete the circuit in a standard cell and allow for the flow of ions between the two half-cells. It also helps to maintain electrical neutrality in the cell, preventing a buildup of charge.

5. How does temperature affect the voltage of a standard cell?

The voltage of a standard cell is directly proportional to the temperature, according to the Nernst equation. As the temperature increases, the voltage of the cell also increases, and vice versa.

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