A student performs a gravimetric analysis experiment to determine the number of moles of water of crystallization, \(x\), per mole of anhydrous cobalt(II) chloride in a hydrated sample, \(\text{CoCl}_2 \cdot x\text{H}_2\text{O}\). The theoretical value of \(x\) is \(6\). The student heats the sample in a covered crucible over a Bunsen burner, cools the crucible to room temperature in a desiccator, and records the mass after successive heatings. The collected data are shown in the table below.

Measurement	Mass
Mass of empty crucible and lid	\(24.500 \text{ g}\)
Mass of crucible, lid, and hydrated sample	\(26.879 \text{ g}\)
Mass of crucible, lid, and sample after first heating	\(25.900 \text{ g}\)
Mass of crucible, lid, and sample after second heating	\(25.800 \text{ g}\)
Mass of crucible, lid, and sample after third heating (intense heating)	\(25.562 \text{ g}\)

When the student calculates the value of \(x\) using the mass recorded after the third heating, the resulting value is significantly greater than \(6\). Which of the following best explains why using the data from the third heating leads to an experimental value of \(x\) that is too large?