Science : Ch 02 – Acids Bases and Salts

Calcium phosphate Ca₃(PO₄)₂  is a basic salt, as it is formed by the combination of a weak acid (phosphoric acid) and a slightly stronger base (calcium hydroxide)

Phenolphthalein solution is a colourless indicator which gives pink colour in basic solution. Phenolphthalein solution remains colourless in acidic solution as well as in neutral solution.

Baking powder is a mixture of sodium hydrogen carbonate and tartaric acid NaHCO₃ + H+ → CO₂ + H₂O + Sodium salt (from tartaric acid) of acid Carbon dioxide (CO₂) produced during reaction can cause bread or cake to rise and makes Baking powder, tartaric acid neutralises the salt and cake does not taste bitter.

The tooth paste commonly used is alkaline or basic in nature as they contain mild bases such as sodium fuoride or sodium bicarbonate in their composition.

Hydrochloric acid and sodium hydroxide are strong acid and base respectively. So blending of strong acid and strong base will form neutral salt and water giving the pH value as 7.

Sodium carbonate (Na₂CO₃) is the salt of carbonic acid (H₂CO₂) and sodium hydroxide (NaOH). Here NaOH is a powerful base and carbonic acid is a weak acid.

C₂H₅OH is not a base. C₂H₅OH is an organic compound with –OH functional group that is known as alcohol

Reaction of sodium hydrogen carbonate with acetic acid forms sodium acetate and water with carbon dioxide (CO₂) gas.

When the pH of an aqueous solution is higher, its acidic properties are weak. Thus, it is a base. When the pH an aqueous solution is lower, its basic properties are weak. Thus, it is an acid.