What is [ OH - ] for a solution where pH = 4.20?

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What is [ OH - ] for a solution where pH = 4.20?

2007-03-09 09:38:22 · 3 answers · asked by Debra B 1 in Science & Mathematics ➔ Chemistry

3 answers

1.58 x 10-10
Find this by finding the pOH then converting it to OH conc. using inverse log. Remember pH + pOH = 14

2007-03-09 09:40:56 · answer #1 · answered by Chess 2 · 0⤊ 0⤋

pH = -log(10)[H+]

therefore [H+] = 10^-pH

= 10^-4.2

= 6.3 x10^-5

[H+] x [OH-] = 1 x10^-14

Therefore [OH-] = 1 x 10^-14 / 6.3 x 10^-5

= 1.6 x10-10

2007-03-09 09:49:02 · answer #2 · answered by Anonymous · 0⤊ 0⤋

14-4.20 = 9.80 = pOH
10^-9.80 = 1.58x10^-10 = [ OH- ]

2007-03-09 09:46:01 · answer #3 · answered by Anonymous · 0⤊ 0⤋