Question

The bone kept in hydrochloric acid becomes soft why

Answer 1

The bone is depleted of calcium but it does not "melt" because there are other minerals that make up the bone such as potassium, vitamins and collagen. Since calcium is the main mineral in the bone, the bone becomes brittle and more susceptible to breakage. HCl is hydrochloric acid, strong acid.

Answer 2

when ball is dropped in hcl medium calcium in bones slowly start dissolve due to action of strong acid afterwards the bone is depleted of calcium but it doesn't melt because there are other minerals that make up The Bone
such as potassium vitamins and collagen