Question

How many grams of Ca is produced when 16.8 grams of Ca reacts in the following reaction. All work must be shown for full credit.

2 Ca + O2 --> 2 CaO

Answer 1

0.6575180 mol CaO

Explanation:

I'll assume it reacts with excess oxygen, and forms only calcium oxide. The chemical equation for this reaction is2Ca(s)+O2(g)→2CaO(s)

First let's calculate the number of moles of Ca

that reacts, using its molar mass: 26.35332g Ca(1mol Ca/40.08g Ca)=0.6575180 mol Ca

Now, let's use the stoichiometrically equivalent values (the coefficients) in the chemical equation to calculate the number of moles of CaO:

0.6575180mol Ca(2mol CaO2mol Ca)=0.6575180mol CaO

Therefore,

0.6575180mol CaO will form.

By the way, I've never seen 7 significant figures used in a problem before, I like it:)