Q4(a). CaCO₃ in a CaCO₃–CaO mixture from the TG mass loss
Thermogravimetric analysis of a mixture of anhydrous CaCO₃ and CaO recorded between 500 °C and 900 °C indicates a weight loss from 290.60 mg to 230.80 mg. Determine the percentage of CaCO₃ in the mixture. Given: molecular weight of CaCO₃ is 100.1 g mol⁻¹ and CaO is 56.1 g mol⁻¹.
Answer in brief
The loss of 59.80 mg is CO₂ from CaCO₃ alone. m(CaCO₃) = 136.05 mg, so CaCO₃ = 46.8 % and CaO = 53.2 %.
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CoversthermogravimetryTGAcalcium carbonate decompositionCaCO3mass loss
All parts of Question 4
- 4(a) CaCO₃ in a CaCO₃–CaO mixture from the TG mass loss10 marks
- 4(b) Interferences in ICP–MS and their elimination10 marks
- 4(c) Ultimate analysis of coal: significance; estimation of ash10 marks