Explanation:
To convert moles to particles or grams to particles, let us have a firm understanding of what a mole is.
A mole is the unit of measuring quantity of particles.
It is the amount of substance that contains the Avogadro's number of particles.
The particle can be atoms, molecules, formula units, electrons, protons, neutrons, etc.
So, to convert from moles to particles;
1 mole of a substance contains 6.02 x 10²³ particles
To convert from grams to particles;
First convert to moles;
number of moles =
So, 1 mole of a substance contains 6.02 x 10²³ particles
Answer:

Explanation:
Hello,
In this case, since hydrochloric acid and barium hydroxide are in a 2:1 molar ratio, for the neutralization, the following moles equality must be obeyed:

In such a way, in terms of molarities and volumes, we can compute the required volume of hydrochloric acid as shown below:

Besr regards.
The correct answer is A
its not D because a low pH is a acid
its not C because a base releases OH- ions
its not B because it donates and releases OH- ions
hope this helps