First we calculate the concentration of HCl:
Moles = mass / Mr
= 25 / 36.5
= 0.685 mol
Concentration = 0.685/1.5 = 0.457 mol / dm³
For a strong monoprotic acid, the concentration of hydrogen ions is equal to the acid concentration.
pH = -log[H+]
pH = -log(0.457)
= 0.34
Answer: yes
Explanation: its common sense
Answer: The net ionic equation will be as follows.

Explanation:
The chemical equation for the given reaction is as follows.

We know that a strong acid or base will dissociate completely into a solvent whereas a weak acid or base dissociates partially into the solvent. Hence, the ionic equation will be as follows.
Now, we will cancel the spectator ions from the above equation. Therefore, the net ionic equation will be as follows.

or,
The best explanation would be that Gases were released during the Chemical reaction, causing a loss of Mass.