Question

Assuming all the NH3 dissolves and that the volume of the solution remains at 0.450 L , calculate the pH of the resulting solution.

Answer 1

Answer:

8.9357.

Explanation:

So, let us dive right into the solution to the above problem;

We have that the volume of the solution = 0.450 L.

The first thing to do is to determine the number of moles by using the formula below:

Pressure × volume = number of moles × gas constant × temperature.

Therefore, making the number of moles the subject of the formula we have;

Number of moles = (pressure × volume)/ has constant × temperature.

Number of moles of NH3=( 735 × 7.50 )/ 62.4 × 295 = 0.2995 moles.

The number of moles of HCl =

0.450 × 0.450 = 0.2025 moles.

Molarity of HCl = 0.2025 moles/ 0.450 L = 0.45M.

The molarity of {OH^-} = (0.2995 moles - 0.2025 moles) /0.450 = 0.097/0.450 = 0.2156 M.

Therefore, kb = 1.8 × 10^-5 = [ 0.450] [OH^-] / [ 0.2156 M] = 0.000008624.

[OH^-] = 0.000008624.

Hence, pOH = 5.0643.

pH = 14 - 5.0643 = 8.9357.