Chemistry Past Questions

Change Subject Ask Question Check Syllabus Download App

The most common type of chemical reaction which alkanes undergo is
  • A. substitution
  • B. addition
  • C. condensation
  • D. polymerisation
  • E. double decomposition
View Answer & Discuss (14)
Consider the following exothermic reaction
2SO2(g) + O2(g) ↔ 2SO3(g)
If the temperature of the reaction is reduced from 800°C to 500°C, an no other change takes place, then
  • A. the reaction rate increases
  • B. concentration of SO3 decreases
  • C. concentration of SO3 increases
  • D. SO2 gas becomes unreactive
  • E. O3 gas becomes unreactive
View Answer & Discuss (16)
If excess zinc is added to a bluish green solution of copper (II) sulphate, and the excess zinc filtered off after completion of reaction, a colourless solution is obtained because
  • A. both zinc and copper are metals
  • B. the sulphate radical and the zinc ion are divalent
  • C. zinc is more electropositive than copper
  • D. both zinc and copper form depositive ions in solution
  • E. zinc is a reducing agent
View Answer & Discuss (15)
Three solutions contain carbonate, sulphate and sulphide ions respectively. One test that will identify just ONE of them completely is by addition to each of them of
  • A. barium chloride solution
  • B. dilute hydrochloric acide
  • C. lead nitrate solution
  • D. calcium chloride solution
  • E. sodium hydroxide solution
View Answer & Discuss (20)
Two gas cylinders contain ethylene (ethene) and acetylene respectively. One test which can be used to distinguish between them is by
  • A. passing each gas through bromine water
  • B. passing each gas through dilute potassium permanganate solution
  • C. passing each gas through silver nitrate solution
  • D. treating each gas catalytically with excess hydrogen gas
View Answer & Discuss (7)