posted by laura on .
a test tube containing CaCo3 is heated until all the compound decomposes. If the test tube plus calcium carbonate originally weighed 30.08 grams and the loss of mass during the experiment is 4.40 grams, what was the mass of the empty test tube?
Write the equation.
CaCO3 ==> CaO + CO2
First, the equation isn't quite clear. The questions gives the impression that CaCO3 COMPLETELY decomposes; in reality, it decomposes into CO2 (which is the loss in mass) but it leaves CaO.
Convert 4.40 g CO2 to mols CO2. Convert that to mols CaCO3. Convert that to grams CaCO3.
Then grams CaCO3 + test tube = 30.08 g
less grams CaCO3 = ??
The difference is the mass of the test tube.
the mass of the test tube is 20.1 grams