A solution of sodium chloride contains the four ions shown in the box - Edexcel - GCSE Chemistry - Question 6 - 2015 - Paper 1
Question 6
A solution of sodium chloride contains the four ions shown in the box.
Na⁺ Cl⁻ OH⁻ H⁺
(a) The sodium chloride solution is electrolysed.
Give the formulae of th... show full transcript
Worked Solution & Example Answer:A solution of sodium chloride contains the four ions shown in the box - Edexcel - GCSE Chemistry - Question 6 - 2015 - Paper 1
Step 1
Give the formulae of the two ions that will be attracted to the positively charged electrode.
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Answer
The two ions that will be attracted to the positively charged electrode (anode) during the electrolysis of sodium chloride solution are Cl⁻ (chloride ion) and OH⁻ (hydroxide ion).
Step 2
Complete the sentence by putting a cross (✗) in the box next to your answer.
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Answer
The correct answer is D: lead and bromine. When molten lead bromide is electrolysed, lead is deposited at the cathode and bromine is released at the anode.
Step 3
Explain, in terms of electrons, what is meant by oxidation and reduction.
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Answer
Oxidation is defined as the loss of electrons. During this process, an atom or ion increases its oxidation state. Reduction, on the other hand, is the gain of electrons. This process leads to a decrease in the oxidation state of an atom or ion. In electrolysis, oxidation occurs at the anode while reduction occurs at the cathode, reflecting the movement of electrons from one species to another.
