eZine · Nigerian exams

Non-metals and their compounds

JAMB Chemistry topic guide with 2 practice questions.

What to revise

  • hydrogen: commercial production from water gas and cracking of petroleum fractions; laboratory preparation, properties, uses and test
  • halogens: chlorine - laboratory preparation, industrial preparation by electrolysis, properties and uses (water sterilization, bleaching, manufacture of HCl, plastics, insecticides); hydrogen chloride and hydrochloric acid; chlorides and test for chlorides
  • oxygen: laboratory preparation, properties, uses; commercial production from liquid air; acidic, basic, amphoteric and neutral oxides; ozone as an allotrope and its importance
  • water: composition by volume; water as solvent; dissolved atmospheric gases; temporary and permanent hardness and softening; treatment for town supply; water of crystallization, efflorescence, deliquescence, hygroscopy
  • sulphur: uses and allotropes (preparation of allotropes not expected); sulphur (IV) oxide; trioxosulphate (IV) acid and its salts; tetraoxosulphate (VI) acid (contact process only) as dilute acid, oxidizing and dehydrating agent; tests for SO4 2-, SO3 2-, SO2; hydrogen sulphide; tests for S2-, H2S
  • nitrogen: laboratory preparation; production from liquid air; ammonia (laboratory and Haber process), ammonium salts, oxidation to nitrogen (IV) oxide and trioxonitrate (V) acid; tests for NH4+, NO2, NH3; trioxonitrate (V) acid and its salts; test for NO3-; oxides of nitrogen; the nitrogen cycle
  • carbon: allotropes; carbon (IV) oxide (laboratory preparation, properties, uses; action of heat on trioxocarbonate (IV) salts; tests for CO3 2-, HCO3-, CO2); carbon (II) oxide (preparation, properties, effect on blood, sources); coal (types, destructive distillation of wood and coal); coke (gasification, uses); synthesis gas

You should be able to

  • predict reagents for the laboratory and industrial preparation of these gases and their compounds
  • identify and compare the properties of the gases and their compounds
  • specify the uses of each gas and its compounds
  • determine the specific test for each gas and its compounds, including Cl-
  • predict reagents for preparation, properties and uses of HCl(g) and HCl(aq)
  • identify the allotropes of oxygen and the significance of ozone
  • classify the oxides and their properties
  • identify the uses of water and the effects of dissolved atmospheric gases
  • distinguish between hard and soft water, the causes of hardness and methods of removal
  • describe the treatment of water for town supply
  • distinguish efflorescence, deliquescence and hygroscopy and identify compounds exhibiting them
  • identify the allotropes of sulphur and their uses
  • predict reagents for preparation, properties and uses of SO2 and H2S
  • specify the preparation, properties and uses of H2SO4 and H2SO3
  • determine specific tests for S2-, SO4 2-, H2S, SO2, SO3 2-
  • specify the laboratory and industrial preparation, properties and uses of NH3 and test for NH4+, NH3
  • identify reagents for the laboratory preparation of HNO3, its properties and uses
  • specify the properties of N2O, NO, NO2 and tests for N2O, NO, NO3-
  • examine the relevance of the nitrogen cycle to the environment
  • identify allotropes of carbon
  • predict reagents for the laboratory preparation of CO2 and CO and specify their properties
  • predict the effects of CO on humans
  • determine the specific tests for HCO3-, CO3 2-, CO2
  • identify forms of coal and their uses; specify products of destructive distillation of wood and coal
  • specify the uses of coke and synthesis gas

From JAMB's Chemistry syllabus official. Full syllabus →

eZine's published bank has 21 questions on this topic (counted 29 October 2026).

Practice questions

Question 1 · Non-metals and their compounds

Dry chlorine does not bleach dry litmus paper, but moist chlorine bleaches it. This is because

Show answer and explanation

Answer: C. with water, chlorine forms chloric(I) acid, which gives oxygen that oxidizes the dye

Cl₂ + H₂O → HCl + HOCl; the chloric(I) acid (HOCl) gives up oxygen which oxidizes the dye to a colourless product, so bleaching is oxidation and needs water. Chlorine is an oxidizing, not reducing, agent; temperature is not the reason; water alone does not bleach.

eZine practice question (original, teacher-reviewed)

Question 2 · Non-metals and their compounds

Ozone in the upper atmosphere is important because it

Show answer and explanation

Answer: C. absorbs harmful ultraviolet radiation from the sun

The ozone layer absorbs most of the sun's UV radiation, which would otherwise cause skin cancer and eye damage. Respiration uses O₂, not O₃; trapping infra-red radiation is the greenhouse effect of CO₂ and water vapour; ozone does not remove CO₂.

eZine practice question (original, teacher-reviewed)

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