Question

5.
A milkman adds a very small amount of baking soda to fresh milk.
(1) Why does he shift of pH of the fresh milk from 6 to slightly alkaline?
(ii) What do you expect to observe when the milk comes to a boil?
(iii) Why does this milk take a long time to set as curd?.​

Answer 1

Explanation:

5.

(1)

Answer:-) By making the milk more alkaline, it takes more time to turn into curd..

(2)

Answer:) On boiling milk will become slightly bitter in taste due to the presence of baking soda.

(3)

Answer:) The value of pH of milk decreases, when it turns into curd. Curd is acidic in nature, because an acidic substance has less value of pH.

As this milk is slightly more alkaline than other, therefore, acid produced to set into curd will be neutralized by baking soda added by milkman. Hence, this milk takes a longer time to set as curd.

hope it helps