The percentage by mass of calcium carbonate in eggshell was determined by adding gues
hydrochloric acid to ensure that all the coloum carbonate had reacted. The eness is left we
then titrated with aqueous sodium hydroxide,
(a) A student added 27.20 crn' of 0.200 mol dm * HCI to 0.188 g of eggshell. Calculate the
amount, in mol of HCI added,
(b) The excess and requires 23,80 cm' of 0.100 mol dm Noow for neutralization, Caliste
the amount, in mol, of acid that is in excess,
(0) Determine the amount, in mol, of HCl that reacted with the caldum carbonate in the
eggshell
(d) State the equation for the reaction of HCl with the calcium carbonate in the eggshell.
(e) Determine the amount, in mol, of calcium carbonate in the sample of the eggshell
,
(0) Calculate the mass and the percentage by mass of caldur carbonate in the eggshell
sample
(9) beduce one assumption made in arriving at the percentage of caldur carbonate in the
eggshell sample.
