calculatign the ph of solution?

A solution that is made by combining 125mL of 0.050 M hydrofluoric acid with 50.0mL of 0.10 M sodium fluoride.

calculate the ph of this solution

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  • 9 years ago
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    For HF, pKa = 3.17

    Moles HF = 0.125 L X 0.05 mol/L = 6.25X10^-3 mol

    moles F- = 0.050 X 0.10 mol/L = 5X10^-3 mol

    Using the Henderson-Hasselbalch equation gives:

    pH = pKa + log [F-]/[HF]

    pH = 3.17 + log (5X10^-3 / 6.25X10^-3) = 3.07

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