Give reason for the following.

A. Hydronium ions are always in the form H₃O⁺

B. Buttermilk spoils if kept in a copper or brass container.

A. Dissociation of water molecule

H₂O ↔ H⁺ + OH^-

As soon as the H⁺ ions are formed, they make bond with water molecules in the solution to form hydronium ion(H₃O⁺). This is because hydrogen cannot exist independently(alone) in the aqueous solutions, and hence take the form of the hydronium ion.

H₂O + H⁺↔ H₃O⁺

Water has ability to attract H⁺ because it is a polar molecule

B. Buttermilk spoils if kept in a copper or brass container because

i. Butter milk contains lactic acid.

ii. The lactic acid present in the buttermilk reacts completely with copper or brass container.

iii. Due to the chemical reaction taking place, the buttermilk becomes unfit for consumption and spoils the buttermilk.