Acids, Bases and Salts Notes

• Basic substances are those which contain bases.
• Some examples of bases are sodium hydroxide (NaOH), Potassium hydroxide (KOH), Calcium hydroxide [Ca (OH)₂], Magnesium hydroxide Mg(OH)₂ etc.

• Bases also occur in plant and animal products such as corn starch, fresh egg white, etc.
• Bases may have a strong irritating odour and should be used with caution as it can harm the skin and eyes.

Bases:

• Indicators are special type of substances that indicate whether a substance is acidic or basic.
• The indicators change their colour when added to an acidic or basic solution.
• Turmeric, litmus, China rose petals (Gudhal), etc., are some of the naturally occurring indicators.

Litmus:

• When an acidic solution is mixed with a basic solution, both the solutions neutralize the effect of each other.
• The resulting solution is neither acidic nor basic.
• In neutralization reaction a new substance is formed which is called salt. Salt may be acidic, basic or neutral in nature.
• The reaction between an acid and a base is known as neutralization.
• Salt and water are produced in this process with the evolution of heat.