(b) John measured the volume of gas produced when 5 g of two chemicals X and Y were added separately to hydrogen peroxide under identical conditions. His results for this experiment are represented on the graph below.
John claimed that Y is a better catalyst than X. His partner Steven did not agree.
Why does Steven think that John’s conclusion is wrong?
After the experiment, Steven recovered 5 g of X and 1 g 1 of Y from the two experiments. He claimed that John was wrong. Does Steven’s claim true? Give a reason.
(b) 25cm 3 samples of water A, B, C and D were tested with soap solution. The volume of soap solution required to produce a lather that lasted for a minute was recorded. Fresh samples of each were boiled and tested again with soap solution. The results are shown in Table 1.
Volume of soap solution required (cm 3 ) before boiling
Volume of soap solution required (cm 3 ) after boiling
Which sample probably contains temporary hardness of water only?
Which sample probably contains both permanent and temporary hardness of water? Give a reason for your answer.
13. 0.48g of a metal, M was placed in a test tube and hot copper (II) sulphate solution was added to it and stirred until the reaction stopped. The metal (M) displaced copper from copper (II) sulphate solution. Copper was filtered, washed with water, dried at 1000 C and the mass found to be 1.27g. Given that, the balanced chemical reaction that occurred is M (s) + CuSO 4(aq) MSO 4(aq) + Cu (s)
The number of moles of copper that were formed and the number of moles of M that were used in the reaction.
The relative atomic mass of M and hence identify metal M.
(b) State the appearance of the metal formed (Cu).
(c) With ionic equations, explain why the reaction can be considered to involve both oxidation and reduction.