SPM Form 4: Salts (Checklist)

• Salts: An ionic compound formed when the hydrogen ion in an acid is replaced by a metal ion or an ammonium ion. Salts are formed as the product of an acid reaction with an alkali. Soluble salts dissolve in water. Insoluble salts do not dissolve in water.
• Recrystallization: A technique used to purify crystals of a soluble salt by carrying out the crystallization process again on these crystals.
• Precipitation reaction: A reaction which involves the reaction between two aqueous reactants to form an insoluble substance.
• Continuous variation method: An experiment which involves the reaction of a solution at fixed volume and another solution with volumes that varies uniformly.
• All carbonate salts are decomposed on heating to liberate carbon dioxide gas, CO₂ except sodium carbonate, Na₂CO₃ and potassium carbonate, K₂CO₃.
• All nitrate salts are decomposed on heating to liberate nitrogen dioxide gas, NO₂ and oxygen gas, O₂ except sodium nitrate, NaNO₃ and potassium nitrate, KNO₃ which liberate oxygen gas, O₂ only.
• The presence of carbonate ions can be confirmed by adding dilute acids.
• The presence of sulphate ions can be confirmed by adding acidified barium chloride, BaCl₂ solution.
• The presence of chloride ions can be confirmed by adding acidified silver nitrate, AgNO₃ solution.
• The presence of nitrate ions can be confirmed by adding dilute sulphuric acid, H₂SO₄ followed by iron (II) sulphate, FeSO₄ solution and a little concentrated sulphuric acid, H₂SO₄.
• The identify of cation can be determined by using sodium hydroxide, NaOH solution and ammonia, NH2 solution except aluminium ion, Al³⁺ and lead (II) ion, Pb²⁺.
• Ammonium ion can be tested by heating with a strong alkali or adding Nessler’s reagent.
• Iron (II) ion and iron (III) ion can be tested by using potassium hexacyanoferrate (II), K₄Fe(CN)₆ solution, potassium hexacyanoferrate (III), K₃Fe(CN)₆ or potassium thiocyanate, KSCN solution.
• Lead (II) ions can be tested by using potassium iodide, KI solution.

SPM Chemistry Syllabus Form 4

Chapter 1: Introduction to Chemistry

1.1 Chemistry and its importance

1:2 Scientific methods

Chapter 2: The Structure of the Atom

2.1 Matter

2.2 The atomic structure

2.3 Isotopes

2.4 The electronic structure of an atom

Chapter 3: Chemical Formulae and Equations

3.1 Relative atomic mass and relative molecular mass

3.2 The mole and the number of particles

3.3 The mole and the mass of substances

3.4 The mole and the volume of gas

3.5 Chemical Formulae

3.6 Chemical Equations

Chapter 4: Periodic Table of Elements

4.1 The Periodic Table of Elements

4.2 Group 18 elements

4.3 Group 1 elements

4.4 Group 17 elements

4.5 Elements in a period

4.6 Transition elements

Chapter 5: Chemical Bonds

5.1 Formation of compounds

5.2 Ionic bonds

5.3 Covalent bonds

5.4 The properties of ionic and covalent compounds

Chapter 6: Electrochemistry

6.1 Electrolytes and non-electrolytes

6.2 Electrolysis of molten compounds

6.3 Electrolysis of aqueous solutions

6.4 Electrolysis in industries

6.5 Voltaic cells

6.6 The electrochemical series

Chapter 7: Acids and bases

7.1 Acids and bases

7.2 The strength of acids and alkalis

7.3 Concentrations of acids and alkalis

7.4 Neutralization

Chapter 8: Salts

8.1 Salts

8.2 Qualitative analysis of salts

Chapter 9: Manufactured Substances in Industry

9.1 Sulphuric acid

9.2 Ammonia and its salts

9.3 Alloys

9.4 Synthetic polymers

9.5 Glass and polymers

9.6 Composite materials