Calculate [H^+], [OH^-] for a solution with pH values

Calculate [H^+], [OH^-] for a solution with pH values

 

 

Calculate the [H3O^+] and [OH^-] for a solution with the following pH values

A. 2.90

B. 9.90

 

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▶ 참고: pH의 정의 https://ywpop.tistory.com/2706

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A.

pH = -log[H^+] = 2.90

[H^+] = 10^(-2.90) = 0.00126 M = 1.26×10^(-3) M

 

[H^+][OH^-] = 10^(-14) 이므로,

[OH^-] = 10^(-14) / (1.26×10^(-3)) = 7.94×10^(-12) M

 

 

 

B.

pH > 7 이상일 경우에는

pH + pOH = 14 로부터,

pOH = 14 – pH = 14 – 9.90 = 4.10

 

pOH = -log[OH^-] = 4.10

[OH^-] = 10^(-4.10) = 7.94×10^(-5) M

 

[H^+][OH^-] = 10^(-14) 이므로,

[H^+] = 10^(-14) / (7.94×10^(-5)) = 1.26×10^(-10) M

 

 

 

▶ pH = 8.90
pOH = 14 – 8.90 = 5.10
[OH^-] = 10^(-5.10) = 7.94×10^(-6) M
[H^+] = 10^(-14) / (7.94×10^(-6)) = 1.26×10^(-9) M

 

 

▶ pH = 11.00
pOH = 14 – 11.00 = 3.00
[OH^-] = 10^(-3.00) = 1.00×10^(-3) M
[H^+] = 10^(-14) / (1.00×10^(-3)) = 1.00×10^(-11) M