What is the pH of a 2.62 x 10 -1 M HCN solution? NB the pKa...

What is the pH of a 2.62 x 10 ^-1 M HCN solution? NB the pK_a for HCN = 9.212.

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Expert Solution

pKa = 9.212

- LogKa = 9.212

Ka = 10^-9.212

Ka = 6.14 * 10^-10

Accoding to Ostwald's theory of weak acids,

[H⁺] = sqrt.(KA* C)

= sqrt.(6.14 * 10^-10 * 2.62 * 10^-1)

= 1.27 * 10^-5 M

Therefore,

pH = - Log[H⁺]

= - log(1.27 * 10^-5)

= 4.90

queen_honey_blossom answered 1 year ago

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