A sample of limestone (impure calcium carbonate) weighing 0.20g was reacted with 50cm' of 0.10mol dm3 hydrochloric acid.
CaCO3(s) + 2HCl(aq) → CaCl2(aq) + CO2(g) + H2O()
The hydrochloric acid was in excess, and the excess HCl(aq) reacted with 14cm of 0.10 mol dm3 sodium
hydroxide. Calculate the percentage by mass of calcium carbonate in the limestone

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