# Question #abd9f

Dec 6, 2014

The theoretical yield is the maximum amount of product that can be obtained if all the reactants react completely according to the equation.

Here is an example:

What is the theoretical yield of magnesium oxide if 1.2g of magnesium is burned in excess oxygen?

$2 M {g}_{\left(s\right)} + {O}_{2 \left(g\right)} \rightarrow 2 M g {O}_{\left(s\right)}$

$2 m o l M g \rightarrow 2 m o l M g O$

${A}_{r} M g = 24$ ${A}_{r} O = 16$

$2 \times 24 = 48 g \rightarrow 2 \left(24 + 16\right) = 80 g$

So 1g Mg $\rightarrow \frac{80}{48} g = 1.66 g$ $M g O$

So 1.2g Mg$\rightarrow 1.66 \times 1.2 = 2.0 g$ $M g O$

That is the theoretical yield.