CHEMISTRY FORM 2
- 1.1 Structure of the atom
- 1.2 Atomic Number and Mass Number
- 1.3 Isotopes
- 1.4 Energy levels and electron arrangement
- 1.5 Development of the Periodic Table
- 1.6 Relative Atomic Mass and Isotopes
- 1.7 Ion Formation
- 1.8 Chemical Formulae
- 1.9 Chemical Equations
- 2.1 Alkali metals (Group I elements)
- 2.2 Alkali Earth Metals (Group II elements)
- 2.3 Halogens (Group VII elements)
- 2.4 Noble gases (Group VIII elements)
- 2.5 Properties and Trends Across the Periodic Table
- 3.1 Bond
- 3.2 Ionic bond
- 3.3 Giant ionic structure
- 3.4 Covalent bond
- 3.5 Co-ordinate bond
- 3.6 Molecular structures
- 3.7 Giant covalent structures
- 3.8 Metallic Bond
- 3.9 Types of bond across a period
- 3.10 Oxides of elements in Period 3
- 3.11 Chlorides of Period 3 elements
- 4.1 What is a salt?
- 4.2 Types of salt
- 4.3 Solubility of salts in water
- 4.4 Methods of preparing salts
- 4.4.1 Reacting a Metal with an Acid
- 4.4.2 Reacting an Acid with a Base (Neutralization)
- 4.4.3 Reacting an Acid with a Carbonate (or hydrogencarbonate of metal)
- 4.4.4 Combining elements Directly (Direct Combination of elements)
- 4.4.5 Precipitation (Double decomposition)
- 4.5 Action of heat on salts
- 4.6 Uses of salts
- 5.1 Electrical conduction
- 5.2 Electrical conductivity of molten substances
- 5.3 Electrical conductivity of substances in aqueous state
- 5.4 Electrolysis
- 5.5 Applications of electrolysis
- 6.1 Allotropes of carbon
- 6.2 Chemical properties of carbon
- 6.3 Carbon (IV) oxide
- 6.4 Carbon (II) oxide (CO)
- 6.5 Large scale production of sodium carbonate and sodium hydrogencarbonate
- 6.6 Effect of carbon (II) oxide and carbon (IV) oxide on the environment
- 6.7 Carbon cycle
Salts: What is a salt?
4.1 What is a salt?
Salt is a familiar concept. Let us share what we know about salt.
- Common salt is an example of salts. What is the chemical name of common salt?
- What are the two elements combined in common salt?
- What have you noticed as a main difference between salts and acids?
- How can we obtain a salt from an acid?
- Define a salt.
Study Table 4.1 which shows other examples of salt and common acids, and use it to answer Questions 3, 4 and 5.
Table 4.1: Some common examples of salts and acids.
Answers to Questions 4.1a
All acids have hydrogen ions (H+). That is what makes them acids. When some or all the hydrogen ions are replaced by a metal, we obtain a salt. A salt is a substance obtained when some or all hydrogen ions in an acid are replaced by metallic ions. Metallic ions include Na+, K+, Mg2+, Ca2+, Al3+, Zn2+, Cu2+, Pb2+, NH4+, and so on. Any metal combined with non-metals, excluding oxides and hydroxides, is a salt.
Identify salts from the following list of substances.
AgOH, Na2S, Cu2S, ZnI2, CaO, PbBr2, Na2CO3, Zn(OH)2, AgNO3, FeBr3, LiCl, Na3PO4, CaHPO4, (NH4)2HPO4, MnO2, Ca3PO4, Na2SO3, Na2PO3
Answers to Questions 4.1b