Reshma is the student of class X in a city school. One day she was sitting in the school garden with her friends during the recess. There was a tall tree at the edge of the garden having a large honeycomb attached to it. Some students were playing cricket in te school playground. Suddenly the cricket ball hit the honeycomb due to which a large numbr of honey-bees started flying here and there. Reshma was stung on her face by a honey-bee. The sting was so painful that Reshma started crying. She was immediately rushed to the science laboratory. One of her classmates Shanta gave her vinegar solution to rub on the stung area to get relief from pain. Another clasmate Amarjit, howerver, asked Reshma to rub baking soda solution on the stung area of face. On rubbing baking soda solution, Reshma felt a lot of relief from pain.
(a) What kind of liquid is injected into the skin when a honey-bee stings a person?
(b) Why did rubbing baking soda solution on the stung area of skin give relief from pain?
(c) What type of chemical reaction takes place when baking soda solution is rubbed on the honey-bee sting area?
(d) Why do you think rubbing the honey-bee sting area with vinegar could not give relief from pain?
(e) Name one plant whose stinging hair on leaves inject a similar liquid to that injected by honey-bee sting and can be treated by rubbing baking soda solution?
(f) What vaues are displayed by Amarjit in this episode?

Explanation

(a) Honey-bee sting injects an acidic liquid into the skin of a person.
(b) Baking soda is a mild base. Being a base, baking soda solution neutralises the acidic liquid injected by honey-bee sting and cancels its effect. This give relief from pain.
(c) Neutralisation reaction (between an acid and a base).
(d) The honey-bee sting injects an acidic liquid into the skin of a person which means that the honey-bee sting contains an acid. Now, vinegar also contains an acid. So, vinegar itself being acidic, cannot neutralise the effect of acidic liquid injected by honey bee sting and hence could not provide any relief from pain.
(e) Nettle plant.
(f) The values displayed by Amarjit in this episode are (i) Awareness (of the acidic nature of honey-bee sting and basic nature of baking soda) (ii) Knowledge (that acids and bases are chemically oposite substances which can neutralise or cancel the effect of each other) and (iii) Desire to remove the suffering of others.