A milkman adds a very small amount of baking soda to fresh milk. (a) Why does he shift the pH of the fresh milk from 6 to slightly alkaline?

Question 12. A milkman adds a very small amount of baking soda to fresh milk.
(a) Why does he shift the pH of the fresh milk from 6 to slightly alkaline?
(b) Why does this milk take a long time to set as curd?
Answer:

He shifts the pH of the fresh milk from 6 to alkaline so that in basic form it will not spoil easily.

This milk takes a long time to set as curd because the lactic acid produced reacts with the baking soda.