Sagot :
The pH refers to the negative logarithm of the hydrogen ion concentration of a solution.
What is pH?
The term pH refers to the negative logarithm of the hydrogen ion concentration of a solution. Let us now solve each question.
a) Since pH = 2.90
[H^+] = Antilog(-2.90) = 1.26 * 10^-3 M
[OH^-] = 1 * 10^-14/ 1.26 * 10^-3 = 7.9 * 10^-12 M
pOH = 14 - 2.90 = 11.1
b) Since pH = 3. 86
[H^+] = Antilog(-3.86) = 1.38 * 10^-4 M
[OH^-] = 1 * 10^-14/ 1.38 * 10^-4 = 7.2 * 10^-11 M
pOH = 14 - 3.86 = 10.14
c)Since pH = 10.81
[H^+] = Antilog(-10.81) = 1.55 * 10^-11 M
[OH^-] = 1 * 10^-14/ 1.55 * 10^-11 = 6.5 * 10^-4 M
pOH = 14 - 10.81 = 3.19
d) Since pH = 4.11
[H^+] = Antilog(-4.11) = 7.8 * 10^-5 M
[OH^-] = 1 * 10^-14/7.8 * 10^-5 = 1.3 * 10^-10M
pOH = 14 - 4.11 = 9.89
e) Since pH = 11.61
[H^+] = Antilog(-11.61) =2.45 * 10^-12 M
[OH^-] = 1 * 10^-14/2.45 * 10^-12 = 4.1 * 10^-3 M
pOH = 14 - 11.61 = 2.39
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