Question

What is the hydronium ion concentration and the ph for an aqueous solution of nh3 that has a hydroxide ion concentration of 2.25 × 10- 2 m?

Answer 1

The hydronium ion concentration in the given solution is 4.44 x 10-13 M, and the pH is 12.35.

Step-by-step explanation:

To find the hydronium ion concentration and pH of an aqueous solution of NH3 with a hydroxide ion concentration of 2.25 x 10-2 M:

Step 1: Write down the chemical equation for the ionization of NH3 in water, which is: NH3 + H2O ⇌ NH4+ + OH-

Step 2: Since NH3 is a weak base, and the hydroxide ion concentration is given, we can assume that the concentration of NH3 is equal to the concentration of OH-. So, the concentration of NH3 is 2.25 x 10-2 M.

Step 3: Use the equation for water autodissociation: Kw = [H3O+][OH-]

Step 4: Substitute the known values into the equation: [H3O+][2.25 x 10-2] = 1.0 x 10-14

Step 5: Solve for [H3O+]: [H3O+] = 1.0 x 10-14 / (2.25 x 10-2) = 4.44 x 10-13 M

Step 6: Calculate the pH using the equation: pH = -log[H3O+]

Step 7: Substitute the value of [H3O+] into the equation: pH = -log(4.44 x 10-13) = 12.35

Therefore, the hydronium ion concentration is 4.44 x 10-13 M and the pH is 12.35.

Answer 2

When ammonium is dissolved in wated, we have, NH3 + H2O >> NH4+ + OHÂŻ pOH = -log[OH-] pOH = -log[2.25x10^-2] pOH = 1.6478 Since pH + pOH=14. Therefore pH = 14 - pOH = 14 - 1.648 = 12.3522. [H+]=10^-pH [H+]=10^(-12.3522) [H+]= 4.3250 * 10 ^(-5)