Four stock solutions are prepared and then diluted as described below

CHEMISTRY · Multi-part · A Level · Chemistry · Acids and bases · Acids and bases

Problem

Four stock solutions are prepared and then diluted as described below. All processes occur at

25\,^{\circ}\text{C}

; assume complete dissociation. • Solution W:

50.0\,\text{mL}

0.200\,\text{M}

\text{NaOH}

is diluted to a final volume of

500.0\,\text{mL}

. • Solution X:

25.0\,\text{mL}

0.100\,\text{M}

\text{Ca(OH)}_2

is diluted to

250.0\,\text{mL}

. • Solution Y:

10.0\,\text{mL}

0.0500\,\text{M}

\text{HCl}

is diluted to

100.0\,\text{mL}

. • Solution Z:

75.0\,\text{mL}

0.0100\,\text{M}

\text{H}_2\text{SO}_4

is diluted to

150.0\,\text{mL}

(treat

\text{H}_2\text{SO}_4

as a strong diprotic acid). (a) Determine the final molarity of hydronium or hydroxide ions produced by each solution after dilution, taking stoichiometry into account. (b) Calculate the pH of each diluted solution to two decimal places. (c) Rank the four solutions from most acidic to most basic and justify the order by referencing your calculated pH values. (d) Identify any solution whose pH lies within

\pm0.10

of neutrality and explain how the dilution affected its position in the ranking.

Related theory

Browse the problem library