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What is the pH of 40.0 mL of a solution that is 0.15 M in CN–...

What is the pH of 40.0 mL of a solution that is 0.15 M in CN– and 0.27 M in HCN? For HCN, use Ka = 4.9 × 10–9.

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Expert Solution

This is a buffer

pH = pKa + log(A-/HA)

pKA = -log(KA) = -log(4.9*10^-9 ) = 8.3098

[A-] = 0.15

[HA] = 0.27

then

pH = pKa + log(A-/HA)

pH = 8.3098 + log(0.15/0.27) = 8.0545

queen_honey_blossom answered 2 years ago
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