Which of the following statements are incorre | vedclass

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(B, C) $1$. The salt of a strong acid and a weak base undergoes cationic hydrolysis, resulting in an acidic solution with $pH < 7$. This is a correct

Vedclass · Accepted Answer

$pH$ of an aqueous solution of $10^{-8} \ M \ HCl$ is $8$.

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(B, C) $1$. The salt of a strong acid and a weak base undergoes cationic hydrolysis, resulting in an acidic solution with $pH $2$. For a salt of a weak acid and a weak base, the $pH$ is determined by the relation $pH = 7 + \frac{1}{2}(pK_{a} - pK_{b})$. If $K_{b}  pK_{a}$, which implies $pH $3$. For a very dilute solution of $HCl$ $(10^{-8} \ M)$, the contribution of $H^{+}$ ions from water cannot be neglected. The total $[H^{+}] = 10^{-8} + 10^{-7} \approx 1.1 	imes 10^{-7} \ M$. Thus, $pH = -\log(1.1 	imes 10^{-7}) \approx 6.96$, which is less than $7$. The statement that $pH$ is $8$ is incorrect.$4$. The conjugate acid of $NH_{2}^{-}$ is formed by adding a proton $(H^{+})$, resulting in $NH_{3}$. This is a correct statement.Therefore, statements $B$ and $C$ are incorrect.

Which of the following statements are incorrect?

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