Which of the following compounds would dissolved in water to give a solution whose pH…

Explanation

Aluminum nitrate (Al(NO3)3) is a salt that dissolves in water to produce hydrogen ions (H\(^+\)), which are acidic:

Al(NO\(_3\))\(_3\) → Al\(^{3+}\) + 3NO\(_3\)\(^-\)

Al\(^{3+}\) + 3H\(^2\)O → Al(OH)\(_3\) + 3H\(^+\)

The released hydrogen ions (H\(^+\)) increase the acidity of the solution, resulting in a pH less than 7.

The other options:

B. Potassium nitrate (KNO\(_3\)) is a neutral salt and does not affect the pH.

C. Nitrous oxide (N\(^2\)O) is a gas and does not dissolve in water to affect pH.

D. Ammonia (NH\(_3\)) is a base and would increase the pH of the solution (make it more alkaline).

So, aluminum nitrate (Al(NO3)3) is the correct answer.