Calculate [H + ] and [OH − ] for each solution at 25°C. Identify each solution as neutral, acidic, or basic.

Question

Calculate [H⁺ ] and [OH⁻ ] for each solution at 25°C. Identify each solution as neutral, acidic, or basic.

pH= 15.4

[H+]=

[OH-]=

pOH= 9.34

[H+]=

[OH-]=

pOH=5.4

[H+]=

[OH-]=

Answer 1

Things you should know:

pH = -log [H+]

pOH = -log [OH-]

pH + pOH = 14

[H+][OH-] = 1x10-14 = Kw

pH = 15.4

[H+] = 1x10^-15.4 = 3.98x10^-16

[OH-] = 1x10^-14 / 3.98x10^-16 = 25

pOH = 9.34

pH + pOH = 14

pH = 14 - 9.34 = 4.66

[H+] = 1x10^-4.66 = 2.19x10^-5

[OH-] = 1x10^-14 / 2.19x10^-5 = 4.6x10^-10

pOH = 5.4

[OH-] = 1x10^-5.4 = 3.98x10^-6

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

H+] = 1x10^-14 / 3.98x10^-6

[H+] = 2.51x10^-9