Question

Помогите с химией. Вычислить pH и pOH 1) раствора HNO3 с концентрацией 0,0001 моль/л 2) раствора KOH с концентрацией 0,001 моль/л

Answer 1

1. HNO3 = H(+) + NO3(-)
C(H+) = C(HNO3) = 0,0001 моль/л
pH = -lg H(+) = -lg 0,0001 = 4

1. KOH = K(+) + OH(-)
C(OH-) = C(KOH) = 0,001 моль/л
pOH = -lg OH(-) = -lg 0,001 = 3
pH = 14 - pOH = 14 - 3 = 11

Answer 2

Calculating pH and pOH of HNO3 Solution:

To calculate the pH and pOH of a solution, we can use the formulas:

pH = -log[H+] pOH = -log[OH-]

1) For the HNO3 solution with a concentration of 0.0001 mol/L: - HNO3 is a strong acid, so it completely dissociates in water to form H+ and NO3- ions. - The concentration of H+ ions is equal to the concentration of the HNO3 solution, which is 0.0001 mol/L. - Using the formula pH = -log[H+], we can calculate the pH.

pH = -log(0.0001) pH = 4

Therefore, the pH of the HNO3 solution with a concentration of 0.0001 mol/L is 4.

Calculating pH and pOH of KOH Solution:

2) For the KOH solution with a concentration of 0.001 mol/L: - KOH is a strong base, so it completely dissociates in water to form K+ and OH- ions. - The concentration of OH- ions is equal to the concentration of the KOH solution, which is 0.001 mol/L. - Using the formula pOH = -log[OH-], we can calculate the pOH.

pOH = -log(0.001) pOH = 3

Since pH + pOH = 14 for any aqueous solution at 25°C, we can calculate the pH of the KOH solution:

pH = 14 - pOH pH = 14 - 3 pH = 11

Therefore, the pH of the KOH solution with a concentration of 0.001 mol/L is 11.