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Calculating hydrochloric acid titration volume
The student titrated a solution containing 0.0045 moles of sodium hydroxide with 0.15 mol/dm³ hydrochloric acid.
The equation for the reaction is:
NaOH + HCl rightarrow NaCl + H_2O
Calculate the volume of hydrochloric acid in cm³ needed in the titration.
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Marking points
- 1 Uses the 1:1 equation ratio and concentration to obtain 0.030 dm³ or equivalent.
- 2 Final volume is 30 cm³.
Full-mark answer
The mole ratio is 1:1, so moles HCl = 0.0045 mol. Volume = n ÷ c = 0.0045 ÷ 0.15 = 0.030 dm³ = 30 cm³.
Why this answer loses marks
I divided concentration by moles and reported that value in cubic centimetres.
Use moles divided by concentration, then convert the resulting volume unit.