A propanoic acid buffer at contains ([ HA ]=0.30 , M ) and ([ A ^-]=0.10 , M )

CHEMISTRY · Single correct · A Level · Chemistry · Acids and bases · Acids and bases

Problem

1.0\,\text{L}

propanoic acid buffer at

25^{\circ}\text{C}

contains

[\text{HA}]=0.30\,\text{M}

and

[\text{A}^-]=0.10\,\text{M}

. What is the minimum amount of solid

\text{NaOH}

(in moles) that must be added so that the buffer’s pH increases by exactly 1.00 unit? (Assume the volume change is negligible.) (a)

1.0\times10^{-1}\,\text{mol}

(b)

2.1\times10^{-1}\,\text{mol}

(c)

1.3\times10^{-1}\,\text{mol}

(d)

2.6\times10^{-1}\,\text{mol}