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Calculate the pH of:

a) 0.1 M HF Ka = 7.2 x 10-4

b) 1 x 10-3 M HNO3

c) 1 x 10-8 M HCl

Respuesta :

a. pH=2.07

b. pH=3

c. pH=8

Further explanation

pH=-log [H⁺]

a) 0.1 M HF Ka = 7.2 x 10⁻⁴

HF= weak acid

[tex]\tt [H^+]=\sqrt{Ka.M}\\\\(H^+]=\sqrt{7.2.10^{-4}\times 0.1}\\\\(H^+]=8.5\times 10^{-3}\\\\pH=3-log~8.5=2.07[/tex]

b) 1 x 10⁻³ M HNO₃

HNO₃ = strong acid

[tex]\tt pH=-log[1\times 10^{-3}]=3[/tex]

c) 1 x 10⁻⁸ M HCl

[tex]\tt pH=-log[1\times 10^{-8}]=8[/tex]