Question

Please do not answer if you are not an expert. You will not like the review if you guess.

Please explain with detail (Ignore the dot in the answer choices)

When the pH is equal to the pk, +1, the ratio of protonated (AH) to de 1:10? protonated (A) (AH:A) is 1:1, 2:1, 1:2, 10:1 or Select one: O 1:10 O 10:1 O 2:1 O 1:2

Answer 1

According to Henderson Hasselbalch equation

$pH = pKa + log\frac{[A^{-}]}{[HA]}$

Given pH = pKa +1

Substituting the value,

$pKa + 1 = pKa+ log\frac{[A^{-}]}{[HA]}$

$1 = log\frac{[A^{-}]}{[HA]}$

$10^{1} = \frac{[A^{-}]}{[HA]}$

So, [A^-] : [HA] = 10 : 1

Hence, [HA] : [A^-] = 1 : 10.

Correct answer is option 2.