Question

If 26.35332 grams of Ca is reacted, how many moles of Calcium Oxide are produced?

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 is

`2"Ca" (s) + "O"_2 (g) rarr 2"CaO" (s)`

First let's calculate the number of moles of `"Ca"` that reacts, using its molar mass:

`26.35332cancel("g Ca")((1"mol Ca")/(40.08cancel("g Ca"))) = color(red)(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"`:

`0.6575180 cancel("mol Ca")((2"mol CaO")/(2cancel("mol Ca"))) = color(blue)(0.6575180 "mol CaO"`

Therefore, `0.6575180 "mol CaO"` will form.

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