The pH of the neutralization point of 0.1 N ammonium hydroxide with 0.1 N HCl is 6.

Explanation:
1. Neutralization reaction: Ammonium hydroxide (NH4OH) is a weak base, and hydrochloric acid (HCl) is a strong acid. When these two substances react, they undergo a neutralization reaction to form water (H2O) and ammonium chloride (NH4Cl).
NH4OH + HCl -> NH4Cl + H2O

2. Ammonium hydroxide dissociation: Ammonium hydroxide partially dissociates in water to form ammonium ions (NH4+) and hydroxide ions (OH-).
NH4OH -> NH4+ + OH-

3. Hydrochloric acid dissociation: Hydrochloric acid dissociates completely in water to form hydronium ions (H3O+) and chloride ions (Cl-).
HCl -> H3O+ + Cl-

4. Formation of ammonium chloride: In the neutralization reaction, the ammonium ions (NH4+) from ammonium hydroxide combine with the chloride ions (Cl-) from hydrochloric acid to form ammonium chloride (NH4Cl). There are no remaining hydroxide or hydronium ions in the solution.
NH4+ + Cl- -> NH4Cl

5. pH of the neutralization point: Since ammonium chloride is a salt, it dissociates completely in water. The resulting solution contains equal concentrations of ammonium ions (NH4+) and chloride ions (Cl-), which do not affect the pH significantly. Therefore, the pH of the neutralization point is determined by the remaining water and any excess hydronium ions (H3O+) or hydroxide ions (OH-) in the solution.

6. In this case, since ammonium hydroxide is a weak base and hydrochloric acid is a strong acid, the resulting solution will have an excess of hydronium ions (H3O+). The pH of a solution is defined as the negative logarithm of the hydronium ion concentration. A high concentration of hydronium ions corresponds to a low pH value.

7. As the concentrations of ammonium hydroxide and hydrochloric acid are both 0.1 N, they react in a 1:1 ratio. Therefore, the concentration of hydronium ions in the resulting solution will also be 0.1 N.

8. The pH of a 0.1 N hydronium ion solution is 1, which indicates that the solution is highly acidic.

9. Thus, the correct answer is option B, pH 6, as the pH of the neutralization point is determined by the excess hydronium ions from the hydrochloric acid.