Hydrofluoric acid is a weak acid ( )

CHEMISTRY · Subjective · A Level · Chemistry · Acids and bases · Acids and bases

Problem

Hydrofluoric acid is a weak acid (

K_a = 7.20 \times 10^{-4}

). Calculate the mass of solid sodium fluoride required to be added into a

250 \text{ cm}^3

solution of

0.00420 \text{ mol dm}^{-3}

HF to form a buffer solution of pH 5.6.