The diagram shows an experiment to compare the speed of reaction when limestone chips are added to acid.
In which test-tube is the reaction most rapid?
The diagram shows how hydrated copper(II) sulfate crystals can be made by reacting copper(II) oxide with dilute sulfuric acid.
Why is the sulfuric acid heated in stage 1?
A. So it will react faster with the copper (III) sulfate crystals.
B. Because copper (III) sulfate crystals will not react with cold dilute sulfuric acid.
C. To make the copper (III) sulfate crystals dissolve faster.
D. So that more copper (III) sulfate can dissolve.
Question 10
Question
The diagram shows how hydrated copper(II) sulfate crystals can be made by reacting copper(II) oxide with dilute sulfuric acid.
Why do crystals form when the hot saturated solution is cooled in stage 5?
A. Because the solubility of copper(iii) sulfate increases with temperature.
B. Because the solubility of copper(iii) sulfate decreases with temperature.
C. Because the solubility of copper(iii) sulfate decreases with temperature, and some copper (iii) sulfate will start to precipitate as the mixture cools.
D. Because the copper(II) sulfate and sulfuric acid molecules need to slow down before they can have successful collisions.
Question 11
Question
Which type of reaction always forms a salt and water?