M25-CHEM-HL-TZ3-P1A-Q35

What is the pH of a buffer solution which contains \( 0.500 \, mol \, dm^{-3} \) of methanoic acid and \( 0.250 \, mol \, dm^{-3} \) of sodium methanoate?
\( pK_a \) (methanoic acid) = 3.75