Solution:
The molecular equation is:
Now, the oxide ion reacts with water to produce hydroxide ions,
The ionic equation is:
The 
ions are present on both the sides, so the net ionic equation becomes,
Now, to determine acid and base, we will look at the definitions
Acid: It is defined as proton donor that is it donates 
ions.
Base: It is defined as proton acceptor that is it accepts ions.
In the ionic equation, water is donating ions to 
therefore it acts as an acid and oxide ion acts as a base.
Im not that’s sure because it’s very confusing let me find out wait
When two waves come in contact with each other while traveling on the same medium, its called constructive interference. Constructive interference happens when two waves come together.
Firstly calculating number of moles of hcl disssolved. The answer would be in the pic above. Concentration of hydrogen ions can be calculated by using that mole amount dividing by 3litres of solution to get 0.003196. Hence the ph of solution will be -log10(h+ concentration) which is equal to 2.495
