pH Practice Worksheet Answers | Answer Key

University:
College Entrance Preparation
Course:
ACT Preparation (Science)
Academic year:

2024
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162

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1
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elongeaborblid

pH practice Acidic = [H+] 1) What is the pH and pOH of a 1.2 x 10^-3 M HCl solution? pH = -log(1.2 x 10^-3) = 2.9 pOH = 14 - 2.9 = 11.1 2) What is the pH and pOH of a 2.34 x 10^-6 M NaOH solution? pOH = -log(2.34 x 10^-6) = 4.6 pH = 14 - 4.6 = 9.4 3) What is the pH and pOH of a solution made by adding water to 15 grams of hydroiodic acid until the volume of the solution is 2500 mL? [H+] in solution moles = 15 g HI x (1 mol HI / 127.91 g HI) = 0.12 moles M = 0.12 moles / 2.5 L = 0.048 M pH = -log(0.048) = 1.3 pOH = 14 - 1.3 = 12.7 4) What is the pH and pOH of a solution that was made by adding 400 mL of water to 350 mL of 5.0 x 10^-5 M NaOH solution? M₁V₁ = M₂V₂ (350 mL)(5.0 x 10^-5 M) = M₂(400 mL + 350 mL) M₂ = 0.0023 pOH = -log(0.0023) = 2.63 pH = 14 - 2.63 = 11.37 5) What is the pH and pOH of a solution with a volume of 5.4 L that contains 15 grams of hydrochloric acid and 25 grams of nitric acid? 15 g HCl x (1 mol HCl / 36.46 g HCl) = 0.41 moles HCl 25 g HNO₃ x (1 mol HNO₃ / 63.01 g HNO₃) = 0.40 moles HNO₃ 0.41 moles + 0.40 moles = 0.81 moles / 5.4 L = 0.15 M pH = -log(0.15) = 0.82 pOH = 14 - 0.82 = 13.18 A swimming pool has a volume of one million liters. How many grams of HCl would need to be added to that swimming pool to bring the pH down from 7 to 4? (Assume the volume of the HCl is negligible) [1 x 10^-4] = moles / 1000000 L moles = ???