Limestone is primarily composed of calcium carbonate
CHEMISTRY · Multi-part · AP · Chemistry · Atomic Structure and Properties · Atomic Structure and Properties
Problem
Limestone is primarily composed of calcium carbonate. A geologist collected a natural limestone sample and a chemist synthesized what was claimed to be pure CaCO₃ in the laboratory. Elemental analyses yielded the following data.
Natural sample: 40.0 g Ca, 12.0 g C, 48.0 g O
Synthetic sample: 15.0 g Ca, 4.4 g C, 18.0 g O
(a) Calculate the mass ratios Ca : C and C : O for each sample.
(b) Using the natural sample as the reference, compute the percent deviation of each ratio for the synthetic sample.
(c) The analytical laboratory considers two samples to be the same compound if the percent deviation of each elemental mass ratio is within 2.0 %. Based on the calculations, determine whether the synthetic product can be accepted as pure CaCO₃ and justify your answer.
(d) Suggest one procedural improvement that could reduce the percent deviation if the samples are intended to match.