A Level OCR Chemistry Electrochemical Cells Questions

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username4386034
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I have a booklet that we have been asked to work through.
I have completed most of the questions so I'm not going to bother typing them out as it will take time.
The only question I'm stuck on is this:

A company was investigating the corrosion of metal parts used in oil rigs in the North Sea. Chemists took two identical bolts. One was unused and the other had been exposed to the seawater for several weeks. They reacted each bolt with dilute sulphuric acid. All the unreacted iron was converted to Fe2+ (aq) ions and the rust reacted to form Fe3+ (aq).

(a) Describe how the chemists would dissolve one bolt and make up the solution to 1.00 dm3.

The chemists investigated making the bolts from a nickel-copper alloy that has high strength and resistance to corrosion. They reacted the alloy with sulphuric acid and filtered off the unreacted solid, which they found was copper.

Ni2+ + 2e- --> Ni -0.25 V
2H+ + 2e- --> H2 0.00 V
Cu2+ + 2e- --> Cu +0.34 V

(b) Use the electrode potentials in the table and explain why only the nickel reacts.



Hope you can help answer these 2 questions
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charco
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(Original post by eilloh)
I have a booklet that we have been asked to work through.
I have completed most of the questions so I'm not going to bother typing them out as it will take time.
The only question I'm stuck on is this:

A company was investigating the corrosion of metal parts used in oil rigs in the North Sea. Chemists took two identical bolts. One was unused and the other had been exposed to the seawater for several weeks. They reacted each bolt with dilute sulphuric acid. All the unreacted iron was converted to Fe2+ (aq) ions and the rust reacted to form Fe3+ (aq).

(a) Describe how the chemists would dissolve one bolt and make up the solution to 1.00 dm3.

The chemists investigated making the bolts from a nickel-copper alloy that has high strength and resistance to corrosion. They reacted the alloy with sulphuric acid and filtered off the unreacted solid, which they found was copper.

Ni2+ + 2e- --> Ni -0.25 V
2H+ + 2e- --> H2 0.00 V
Cu2+ + 2e- --> Cu +0.34 V

(b) Use the electrode potentials in the table and explain why only the nickel reacts.



Hope you can help answer these 2 questions
Yes, I can help.

You tell me what you are doing and I'll tell you where to go ...
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username4386034
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i don’t even know where to start with answering the questionhence why i’m asking for help
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charco
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(Original post by eilloh)
i don’t even know where to start with answering the questionhence why i’m asking for help
surely you know how to answer part (a) ...
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username4386034
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(Original post by charco)
surely you know how to answer part (a) ...
no
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charco
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(Original post by eilloh)
no
The question tells you to dissolve it in sulfuric acid and then make the solution up to 1000ml.

What is there not to understand?
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