A student wants to make pure, dry crystals of copper sulfate from copper oxide (an insoluble black powder) and dilute sulfuric acid.
Plan a method the student could use.
In your answer, explain the reason for each step.
[6 marks]Edexcel GCSE Chemistry June 2022 Paper 1F
5 questions on this paper's topics
27:001 of 5
Silicon dioxide (silica) melts at 1710 °C. Poly(ethene) softens at about 120 °C. Methane boils at −162 °C.
Explain the differences in these temperatures.
Refer to the structure and bonding of each substance.
[6 marks]A student heats 2.40 g of magnesium ribbon in an open crucible. It all reacts to form 4.00 g of magnesium oxide.
.1
Calculate the mass of oxygen that reacted with the magnesium.
[1 mark].2
The student says: "The mass went up, so mass was not conserved."
Explain why the student is wrong.
[2 marks].3
The student repeats the experiment in a sealed container full of air and weighs the whole container. Predict what happens to the total mass.
[1 mark]The table shows the boiling points of some noble gases.
| Noble gas | Boiling point in °C |
|---|---|
| Helium | −269 |
| Neon | −246 |
| Argon | −186 |
| Krypton | ? |
| Xenon | −108 |
.1
Estimate the boiling point of krypton.
[1 mark].2
Describe the trend in boiling point down the group.
[1 mark].3
Explain why the noble gases are unreactive.
[2 marks]A student has samples of tap water, sea water and rain water.
Plan an investigation to compare the pH and the mass of dissolved solids in the three samples, and to purify the sea water by distillation.
[6 marks]