pH value of which of the following is not equal to one

Options

A. `0.1 " M "HNO_(3)`
B. `0.05 " M " H_(2)SO_(4)`
C. `0.1 " M " CH_(3)COOH`
D. `50 cm^(3) " of " 0.4 " M " HCl + 50 cm^(3) " of " 0.2 ` M NaOH

Answer

C

Explanation

`pH = - log [H^(+)] `
Value of `pH = 0.1 M HNO_(3)= - log [0.1] = 1 `
(b) Value of `pH = 0.05 H_(2)SO_(4) = - log [2 xx 0.05] = 1 `
(c ) Value of `pH = 0.1 M CH_(3)COOH != 1 ` as it is a weak acid so, will not undergo complete ionization.
(d) Milli - equivalent of base = `50 xx 0.4 = 20 `
Milli - equivalent of base = `50 xx 0.2 = 10 `
Remaining acid = ` 20 - 10 = 10 ` milli -eq.
`[H^(+)] = 10/(50+50) = 10/100 = 0.1 `
`pH = - log [H^(+)] = 1 `