Explanation:
The reaction is as follows:
2Mg(s) + O2(g) ---> 2MgO(s)
and the researcher said that 32 g of MgO was produced.
Stoichiometry:
28 g Mg × (1 mol Mg/24.305 g Mg) = 1.15 mol Mg
15 g O2 × (1 mol O2/15.999 g O2) = 0.938 mol O2
1.15 mol Mg × (2 mol MgO/2 mol MgO) = 1.15 mol MgO
1.15 mol MgO × (40.3044 g MgO/1 mol MgO) = 46.6 g MgO
0.938 mol O2 × (2 mol MgO/1 mol O2) = 1.88 mol MgO
1.88 mol MgO × (40.3044 g MgO/1 mol MgO = 75.6 g MgO
Based on these numbers, the amount of product after the reaction is much less than expected so these results don't seem to support the law of conservation of matter.
