Quantitative Chemistry: Conservation of Mass

Question 1

What is the law of conservation of mass?

Answer 1

No atoms are lost of made during a chemical reaction so the mass of the products equals the mass of the reactants.

Question 2

The following reaction occurs in a test tube under a Bunsen Burner:
4MgO_(s) + CH_4(g) → 4Mg_(s) + 2H₂O_(g) +CO_2(g)
The mass of the products is less than the mass of the reactants. Explain why.

Answer 2

The products are gases so escaped