Anonymous
Anonymous asked in Science & MathematicsChemistry · 2 months ago

What is the pH of a buffer system that contains 0.240 M hydrocyanic acid (HCN) and 0.330 M sodium cyanide (NaCN)? ?

The pKa of hydrocyanic acid is 9.31.

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  • 2 months ago

    HCN is a weak acid with a pKa as you said of 9.31.

    HCN<----> H+ + CN-

    pH=pKa+log[[CN-/HCN]]

    pH=9.31+log[0.33/0.24]

    =9.44

    as you can tell the base salt dominates a bit.

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