The decomposition of CaCO3 is given by the equation: CaCO3(s) → CaO(s) + CO2(g) A student heats a 5 g pellet of CaCO3 strongly for 10 minutes over a Bunsen burner flame. After cooling, the student uses an open container to measure the mass of the products formed and finds this to be 2.8 g. Provide an explanation for the decrease in mass of the products compared to the reactant and work out how many molecules of carbon dioxide would form in this reaction.

Must show your work. Include appropriate significant figures and units.​