Multiple choice

A water sample has a pH of 9.25. The concentration of hydroxyl ions in the water sample is

  1. 10-9.25 moles/L

  2. 10-47.5 m moles/L

  3. 0.302 mg/L

  4. 3.020 mg/L
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Given pH = 9.25, pOH = 14 - 9.25 = 4.75. The concentration of OH- is 10^-4.75 moles/L. Converting this to mg/L: 10^-4.75 moles/L * 17 g/mole * 1000 mg/g = 17 * 10^-4.75 mg/L, which is approximately 0.302 mg/L.

Keep practicing — related questions