---
title: "A student analyzes a solid mixture containing \\(\\text{CaCO}_3\\) and an inert substance that does not decompose upon heating. The student heats a \\(5.00\\text{ g}\\) sample of the mixture strongly until all of the \\(\\text{CaCO}_3(s)\\) has completely decomposed according to the reaction below.  \\[ \\text{CaCO}_3(s) \\rightarrow \\text{CaO}(s) + \\text{CO}_2(g) \\]  After heating to constant mass and cooling, the mass of the remaining solid residue is \\(4.12\\text{ g}\\). Assuming all of the mass lost is due to the evolution of \\(\\text{CO}_2(g)\\), what was the mass percent of \\(\\text{CaCO}_3\\) in the original mixture?"
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url: "https://nerd-notes.com/ubq/120157/"
date_modified: "2026-08-21T16:02:39+00:00"
---

# A student analyzes a solid mixture containing \(\text{CaCO}_3\) and an inert substance that does not decompose upon heating. The student heats a \(5.00\text{ g}\) sample of the mixture strongly until all of the \(\text{CaCO}_3(s)\) has completely decomposed according to the reaction below.

\[ \text{CaCO}_3(s) \rightarrow \text{CaO}(s) + \text{CO}_2(g) \]

After heating to constant mass and cooling, the mass of the remaining solid residue is \(4.12\text{ g}\). Assuming all of the mass lost is due to the evolution of \(\text{CO}_2(g)\), what was the mass percent of \(\text{CaCO}_3\) in the original mixture?

A student analyzes a solid mixture containing \(\text{CaCO}_3\) and an inert substance that does not decompose upon heating. The student heats a \(5.00\text{ g}\) sample of the mixture strongly until all of the \(\text{CaCO}_3(s)\) has completely decomposed according to the reaction below.

\[ \text{CaCO}_3(s) \rightarrow \text{CaO}(s) + \text{CO}_2(g) \]

After heating to constant mass and cooling, the mass of the remaining solid residue is \(4.12\text{ g}\). Assuming all of the mass lost is due to the evolution of \(\text{CO}_2(g)\), what was the mass percent of \(\text{CaCO}_3\) in the original mixture?

- **A.** \(17.6\%\)
- **B.** \(21.4\%\)
- **C.** \(22.4\%\)
- **D.** \(40.0\%\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/120157/*