Question

in an experiment, some magnesium ribbon is weighed and its mass is recorded. it is then placed in a crucible and heated. once hot enough, it combines with oxygen to form magnesium oxide (mgo). observe the data table provided. explain why the law of conservation of mass appears violated.
a the mass of the magnesium oxide was not calculated correctly.
b the mass of the oxygen does not equal the other two substances.
c the masses of the products and reactants look like they are equal.
d the mass of the magnesium oxide does not add up to the oxygen and magnesium.

Explanation:

Step1: Calculate sum of reactants

Sum = Mass of Mg + Mass of O = $4.57 + 2.38 = 6.95$ grams

Step2: Compare to product mass

Product mass (MgO) = 6.53 grams
$6.95
eq 6.53$

Step3: Analyze options

The product mass does not equal the sum of reactants, so the law seems violated because the MgO mass does not add up to Mg + O.

Answer:

D. The mass of the magnesium oxide does not add up to the oxygen and magnesium.