Which of the following salt solutions turns r | vedclass

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(A) salt solution that turns red litmus blue must be basic in nature. $NH_4CN$ is a salt of a weak acid $(HCN)$ and a weak base $(NH_4OH)$. The $pH$ o

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$NH_4CN$

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(A) salt solution that turns red litmus blue must be basic in nature. $NH_4CN$ is a salt of a weak acid $(HCN)$ and a weak base $(NH_4OH)$. The $pH$ of such a salt is given by the formula $pH = 7 + \frac{1}{2}(pK_a - pK_b)$. For $HCN$,$K_a = 6.2 	imes 10^{-10}$ $(pK_a \approx 9.21)$ and for $NH_4OH$,$K_b = 1.8 	imes 10^{-5}$ $(pK_b \approx 4.74)$. Since $pK_a > pK_b$,the resulting solution is slightly basic $(pH > 7)$. $NH_4Cl$ and $NH_4NO_3$ are salts of a strong acid and a weak base,making them acidic. $NaNO_3$ is a salt of a strong acid and a strong base,making it neutral.

Which of the following salt solutions turns red litmus blue?

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