A.He
because He 's molecular weight is small than each other
The mass of nitric acid required to make the given solution is 0.0627 g.
The given parameters:
- <em>Volume of the acid, V = 250 mL</em>
- <em>pH of the acid, = 2.4</em>
The hydrogen ion (H⁺) concentration of the nitric acid is calculated as follows;

The molarity of the nitric acid is calculated as follows;

The number of moles of the nitric acid is calculated as follows;

The molar mass of nitric acid is calculated as;

The mass of the nitric acid contained in the calculated number of moles is calculated as;

Thus, the mass of nitric acid required to make the given solution is 0.0627 g.
Learn more about molarity of acids here: brainly.com/question/13864682
Answer is: both reactions
are exothermic.
<span>
In exothermic reactions, heat is released and enthalpy of reaction is less than
zero (as it show second chemical reaction).
According to Le Chatelier's principle when the reaction
is exothermic heat is included as a product (as it show first
chemical reaction).</span>
Answer:
I think its might be 1 because the ionic numbers for CA is +2 and for P its +3