Chemistry Past Paper

Topics: Chlorine, Sodium hydroxide, Acid Pages: 20 (3681 words) Published: August 27, 2013
Section A (Answer ALL questions in this Section.)

1.Rubidium (Rb) and potassium belong to the same group in the Periodic Table. The relative atomic mass of rubidium is larger than that of potassium. (a)Explain whether rubidium is more reactive than potassium. (b)Write a chemical equation for the reaction between rubidium and water. (State symbols should be given.) (c)Suggest how rubidium can be stored safely in the laboratory. (d)Suggest ONE safety precaution for handling rubidium in the laboratory. (5 marks)

|1. |(a) |Rb is more reactive than K because Rb can give away/donate/release its (outermost) electron more | | | | | |easily/readily. | |1 | | | |or, Rb can form ion/cation/positive ion more easily/readily. | |(1) | | | |or, The strength of metallic bond between Rb atoms is weaker than that between K atoms/Rb can atomize more | | | | | |readily than K. | |(1) | | | |(DO NOT accept Rb has one more electron shell than K/Rb atom is larger than K atom/Rb is below K in the | | | | | |Periodic Table.) | | | | |(b) |[pic] | |1+1 | | | |or, [pic] | |(1+1) | | | |(Formulae of reactants and products must be correct; award 1 mark for a balanced equation and 1 mark for | | | | | |correct state symbols.) | | | | |(c) |Store under oil/paraffin oil/kerosene | |1 | | |(d) |Wear gloves/do not touch directly/use a pair of forceps/wear safety spectacles (goggles)/use a safety screen | | | | | |(DO NOT accept fume cupboard) | |1 |

2.In each of the following groups of substances, there is ONE substance which is different from the others in terms of their properties. In each group, identify the substance which is different from the others and explain your choice. (a)argon, fluorine, helium, neon

(b)nylon, perspex, polyethene, urea-methanal
(c)milk of magnesia, soap, vinegar, window cleaner
(d)carbon monoxide, hydrogen, methane, nitrogen
(8 marks)

|2. |(a) |fluorine | | | | | |fluorine is reactive/yellow/coloured gas | |1+1 | | | |or, others are inert/unreactive/stable/colourless (gases). | | | | | |(DO NOT accept noble gas/halogens.group VII (0) element) | | | | |(b) |Urea-methanal | | | | | |It is a thermosetting plastic (cannot be softened by heat)/the other substances are thermoplastics (can be | | | | | |softened by heat) | |1+1 |...
Continue Reading

Please join StudyMode to read the full document

You May Also Find These Documents Helpful

  • Chemistry Past Paper
  • Chemistry Paper
  • Chemistry Papers
  • Chemistry Essay
  • chemistry Essay
  • Chemistry Past Paper
  • Foundation Chemistry Past Paper
  • Past Paper

Become a StudyMode Member

Sign Up - It's Free