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 soda’s formula does not show any relationship water molecules.

If 10 ml of H₂SO₄ is mixed with 10 ml of Mg(OH)₂ of the same concentration, the result solution be MgSO₄ which is a neutral salt and universal indicator will give the green colour in this 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.

Acids turn blue litmus solution to red. They have a sour taste as in the case of vinegar and are sticky to touch. On the other hand, bases turn red litmus solution to blue. Bases are bitter in taste as in the case of baking soda and are slippery to touch.

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.

Lime (CaO) is the base that reacts with a dilute acid such as HCl to form a salt called calcium chloride.

Chloralkali process is an industrial process that is used to form sodium hydroxide by electrolysis of aqueous solution of sodium chloride NaCl