Question

in the chemical reaction shown below, what is the beginning mass of mercuric oxide? 2hgo (? grams) → 2hg (200 grams) + o₂ (16 grams)

Explanation:

Step1: Apply law of conservation of mass

According to the law of conservation of mass, the total mass of reactants equals the total mass of products in a chemical reaction.

Step2: Calculate mass of reactant

The mass of products is the sum of the mass of mercury ($Hg$) and oxygen ($O_2$). So, mass of $HgO$ (reactant) = mass of $Hg$ + mass of $O_2$.
Mass of $HgO=200 + 16$

Answer:

216 grams