Figure 3 shows the apparatus that can be used to electrolyse sodium sulfate solution using inert electrodes - Edexcel - GCSE Chemistry - Question 2 - 2020 - Paper 1
Question 2
Figure 3 shows the apparatus that can be used to electrolyse sodium sulfate solution using inert electrodes.
(a) Hydrogen is produced at the negative electrode duri... show full transcript
Worked Solution & Example Answer:Figure 3 shows the apparatus that can be used to electrolyse sodium sulfate solution using inert electrodes - Edexcel - GCSE Chemistry - Question 2 - 2020 - Paper 1
Step 1
Describe the test to show the gas is hydrogen.
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Answer
To test for hydrogen gas, a lighted splint should be applied to the gas. When the splint comes into contact with hydrogen, it will produce a distinctive 'pop' sound, confirming the presence of hydrogen.
Step 2
What is the name of gas X that forms at the positive electrode?
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The gas that forms at the positive electrode is ammonia.
Step 3
Calculate the concentration of this solution in g dm⁻³.
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Answer
To find the concentration, use the formula:
ext{Concentration} = rac{ ext{mass of solute (g)}}{ ext{volume of solution (dm}^3 ext{)}}
The mass of sodium sulfate dissolved is 28.4 g and the volume of the solution is 250 cm³, which is equivalent to 0.250 dm³. Therefore,
