Explain importance of pH in everyday life."The aqueous solution of the salt produced by neutralisation of weak acid and strong base possesses basic nature, while aqueous solution of salt produced by neutralisation of weak base and strong acid possesses acidic nature" - Explain. Answer the following questions in detail.
Answers
1. pH in our digestive system
Our stomach produces HCL acid.This HCL acid helps in digesting our food without harming the stomach.Sometimes excess of acid is produced in the stomach.The excess acid in the stomach causes indigestion which produces pain and irritation.In order to cure indigestion, we can take bases called antacids. Being basic in nature, antacid react with excess acid in the stomach and neutralises it. The two common antacids are Milk of Magnesia (Magnesium Hydroxide)and Sodium Bicarbonate(Baking soda)
2.pH change as the cause of tooth decay
When we eat food containing sugar, then the bacteria present in our mouth break down the sugar to form acids.This acid lowers the pH in the mouth.Tooth decay starts when the pH of acid formed in the mouth falls below 5.5.This is because then the acid becomes strong enough to attack the enamel of our teeth and corrode it.This sets in tooth decay.The best way to prevent tooth decay is to clean the mouth thoroughly after eating foOD.
3. Self Defence by animals and plants through chemical warfare
Many animals and plants protect themselves from enemies by injecting painful and irritating acids and bases into their skin.
When honey bee stings a person, it injects an acidic liquid into the skin.Rubbing with mild base like baking soda solution on the stung area of the skin gives relief.
When a wasp stings,it injects an alkaline liquid into the skin.Then rubbing with a mild acid like vinegar on the stung area of the skin gives relief.
ii)
when we break a salt (action of heat, electricity) then we get its a cidic and basic components . the compnent which is more strong is responsible for the nature of the salt
eg: AlCl3
acidic component : hydro chloric acid
basic component : aluminium hydroxide
as hydrochloric acid is more strong as compared to aluminium hydroxide this salt will have an acidc nature
HOPE THIS HELPS !!
Answer:
- When weak acid reacts with strong base, conjugate base of weak acid is formed.
- Thus aqueous solution of its salt will have basic nature.
- On the other hand when strong acid reacts with weak base, conjugate acid of weak base is formed.
- Thus aqueous solution of its salt will have acidic nature.