An unknown monoprotic acid HA with a concentration of 0.050 M has a pH of 2.3. Which of the following can we conclude? A) It must be a strong acid.
B) It must be a weak acid.
C) A salt of its conjugate base would have no pH effect in solution.
D) Both A and C
E) None of the above

B) It must be a weak acid.

Explanation:

If HA is a strong acid

Now the pH value can be written as follows

But given that acid HA has 2.3 pH value.

Therefore we can say that HA is weak acid.

Thus the answer will be option (B).

B) It must be a weak acid.

n has four pairs of electrons in the valence shell, electrons repel one another ,n has 7 protons in its nucleus, and since n has 7 protons, it must fill the second shell, giving it 4 pairs of electrons. the electrons form 3 bonds and 1 lone pair of electrons. each pair of electrons repels the other pairs, so they are equally far apart.

so all of the above