NSC Physical Sciences Electrochemistry: Define the term electrolyte. Is

Define the term electrolyte - NSC Physical Sciences - Question 9 - 2021 - Paper 2

Question 9

Define the term electrolyte. Is the pure chromium metal the ANODE or the CATHODE of the cell? Give a reason for the answer. Write down the half-reaction that takes... show full transcript

Worked Solution & Example Answer:Define the term electrolyte - NSC Physical Sciences - Question 9 - 2021 - Paper 2

Step 1

Define the term electrolyte.

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Answer

An electrolyte is a substance that, when dissolved in water, produces a solution that conducts electricity. It contains ions that move freely and facilitate the conduction of electric current.

Step 2

Is the pure chromium metal the ANODE or the CATHODE of the cell? Give a reason for the answer.

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Answer

The pure chromium metal is the CATHODE of the cell. This is because oxidation takes place at the anode where chromium ions ( ext{Cr}^{3+}) gain electrons and get reduced to pure chromium.

Step 3

Write down the half-reaction that takes place at the ring.

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Answer

The half-reaction at the ring can be written as follows:

ightarrow ext{Cr}$$

Step 4

Calculate the total charge transferred when the mass of the pure chromium changes by 2 g.

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Answer

To find the total charge transferred, we first need to calculate the number of moles of chromium:

$n = rac{m}{M} = rac{2 ext{ g}}{52 ext{ g/mol}} = 0.03846 ext{ mol}$

Next, we find the number of electrons involved in the reaction. Since one chromium atom requires 3 electrons for reduction, we calculate the total number of electrons:

$n(e^-) = 0.03846 ext{ mol} imes 3 = 0.11538 ext{ mol}$

Converting this to total charge using Faraday's constant ( ext{F} = 96,485 ext{ C/mol}):

$Q = n(e^-) imes F = 0.11538 ext{ mol} imes 96,485 ext{ C/mol} = 11,119.68 ext{ C}$

Therefore, the total charge transferred when the mass of the pure chromium changes by 2 g is approximately 11,119.68 C.

Define the term electrolyte - NSC Physical Sciences - Question 9 - 2021 - Paper 2

Worked Solution & Example Answer:Define the term electrolyte - NSC Physical Sciences - Question 9 - 2021 - Paper 2

Define the term electrolyte.

Is the pure chromium metal the ANODE or the CATHODE of the cell? Give a reason for the answer.

Write down the half-reaction that takes place at the ring.

Calculate the total charge transferred when the mass of the pure chromium changes by 2 g.

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