Chemistry Form 4

Contents

1. 1. Non-metals and Their Compounds (Part 1): Nitrogen

   1 tests 17 questions

   Topic lessons

   • Nitrogen: occurrence, preparation and properties
   • Ammonia: preparation and properties
   • The Haber process and uses of ammonia
   • Nitric acid
   • Nitrogen fertilizers and the nitrogen cycle
   • Summary

   Nitrogen Nitrogen (N 2 ) makes up about 78% of air. It is obtained industrially by fractional distillation of liquid air. In the laboratory it can be made by gently warming a solution of ammonium chloride and sodium nitrite: NH 4 Cl + NaNO 2 → NaCl + N 2 + 2H 2 O. Nitrogen is colourless, odourless, slightly less dense…

2. 2. Non-metals and Their Compounds (Part 2): Sulphur and Chlorine

   1 tests 17 questions

   Topic lessons

   • Sulphur: occurrence, allotropes and properties
   • Sulphur dioxide
   • Sulphuric acid: the Contact process
   • Properties and uses of sulphuric acid
   • Chlorine: preparation and properties
   • Uses of chlorine, hydrogen chloride and chlorides
   • Summary

   Sulphur Sulphur is a yellow non-metal found free near volcanoes and combined in ores (sulphides) and in petroleum and natural gas. It has two crystalline allotropes (different forms of the same element in the same state): rhombic sulphur (stable below 96 °C) and monoclinic (needle-shaped) sulphur. Sulphur burns with a…

3. 3. Organic Chemistry (Part 1): Hydrocarbons

   1 tests 16 questions

   Topic lessons

   • Introduction to organic chemistry and sources of hydrocarbons
   • Homologous series and the alkanes
   • The alkenes
   • The alkynes and comparing hydrocarbons
   • Isomerism and naming organic compounds
   • Summary

   What is organic chemistry? Organic chemistry is the study of carbon compounds (except simple ones like CO, CO 2 and carbonates). Carbon forms millions of compounds because each atom forms four covalent bonds and carbon atoms can join to each other in long chains, branches and rings ( catenation ). Sources: petroleum,…

4. 4. Organic Chemistry (Part 2): Alcohols, Acids and Polymers

   1 tests 17 questions

   Topic lessons

   • Alcohols and the production of ethanol
   • Properties and uses of ethanol
   • Carboxylic acids and esters
   • Soaps and detergents
   • Polymers and plastics
   • Summary

   Alcohols (C n H 2n+1 OH) Alcohols contain the hydroxyl group, –OH . Names end in -ol : methanol CH 3 OH, ethanol C 2 H 5 OH, propan-1-ol C 3 H 7 OH. Making ethanol: (1) Fermentation – yeast enzymes convert sugar (glucose) to ethanol and carbon dioxide at about 25–35 °C without air: C 6 H 12 O 6 → 2C 2 H 5 OH + 2CO 2 .…

5. 5. Soil Chemistry

   1 tests 17 questions

   Topic lessons

   • Soil: composition, formation and profile
   • Physical properties of soil
   • Chemical properties of soil: pH and cation exchange
   • Plant nutrients
   • Fertilizers and manures
   • Summary

   What is soil? Soil is the loose top layer of the earth's crust in which plants grow. It consists of mineral matter (about 45%), organic matter /humus (about 5%), water (about 25%) and air (about 25%), together with living organisms. Soil forms by weathering of rocks: Physical: temperature changes, water, wind and plant…

6. 6. Environmental Pollution

   1 tests 16 questions

   Topic lessons

   • Pollution and the main air pollutants
   • Acid rain, the greenhouse effect and the ozone layer
   • Water pollution
   • Land pollution and the control of pollution
   • Summary

   Meaning of pollution Environmental pollution is the introduction into the environment of harmful substances or energy ( pollutants ) that damage living things or property. Pollution may affect air, water or land, and also includes noise. Air pollution Pollutant Main source Effect Carbon monoxide (CO) Incomplete burning…

7. 7. Qualitative Analysis

   1 tests 17 questions

   Topic lessons

   • Introduction to qualitative analysis and preliminary tests
   • Tests for gases
   • Tests for cations
   • Tests for anions
   • Identifying unknown salts
   • Summary

   What is qualitative analysis? Qualitative analysis is the identification of the substances (ions) present in a sample, without measuring their amounts. A salt is analysed by: observing its appearance, heating it, flame test, and tests of its solution for the cation and the anion . Preliminary tests Colour: blue/green…