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Short notes are used to highlight important points, videos used to explain the use of these substances in everyday life, thereby bringing to life the concepts. A crossword puzzle is used as an assessment for learning tool at the end of the lesson. it evaluates students learning in a different format.

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A base is an oxide or hydroxide of a metal

Most bases are insoluble in water. Bases which are soluble in water is called an alkali.
Examples of alkalis

NaOH

Na ₂ O

ZnO

Ag ₂ O

CaO

Al(OH)₃

KOH

LiOH

Pb(OH)₂

Properties of alkalis

1.     They turn red litmus paper blue

2.     They have a bitter taste

3.     They feel soapy

4.     They react with acid to produce a salt and water as the only products.

Acid (aq) + Alkali  (aq) ®salt ( aq)and water (l)

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Salts

A salt is a compound formed when the replaceable hydrogen atoms of an acid are replaced by metal atoms.

To obtain the formula of a salt follow these steps.

1.     Replace the hydrogen of the acid by the metal atom

2.     Using valency balance the formula of the salt

Example: Mg (s) + H ₂ SO 4  ——> MgSO 4 (aq)

2    2

Mg    SO 4

There are two types of salts: normal salts and acidic salts

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An acid is a substance which contains replaceable hydrogen atoms, and when added to water dissociates into hydrogen ions.

Acid + water ———> hydrogen ions.
A strong acid is one which gives up its hydrogen atoms readily and easily when added to water. i.e a strong acid undergoes full dissociation into H⁺ ions when added to water.     Examples of strong  acids:
Hydrochloric acid- HCl- found in the stomach

Nitric acid- HNO ₃

Sulphuric acid- H ₂ SO ₄ Carbonic acid- H ₂ CO 3
Phosphoric acid- H ₃ PO ₄

A weak acid is one undergoes partial dissociation with H+ ions when added to water.

Weak acid + water ® partial dissociation producing small amounts of H⁺ ions.

Example:
(vinegar) Ethanoic acid- CH ₃ COOH Properties of acids:

1.     They have a sour taste

2.     They are corrosive

3.     They turn blue litmus paper red

4.     Acids produce an effervescent reaction when added to a carbonate

5.     Acids react with metals to produce hydrogen gas

6.     Acids react with reactive metals to produce a salt and hydrogen gas

7.     Acids react with Metal oxide (bases) to form salt and water

8.     Acids reacts with metal hydroxides to form salt and water

9.     Acids reacts with metal carbonate to form a salt, carbon dioxide and water.

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Acids + Bases Made Easy! Part 1 - What the Heck is an Acid or Base - Organic Chemistry

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pH is a measurement of how acidic or alkaline (basic) a substance is.  A pH scale is used to measure how acidic or basic a liquid is. pH is a number from 0 to 14. From 0 to 7 are acids, with 0 being the strongest. From 7 to 14 are bases with 14 being the strongest base. If a liquid has a pH of 7, it's neutral. This would be something like distilled water.

An indicator can also be used to determine whether a substance is acidic or basicAn indicator is a chemical which is one colour in an acidic solution and another color in an alkaline solution.

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What are Indicators and how do we use them - The Chemistry Journey - The Fuse School