# A reaction of #53.1 "g"# of #"Na"# and #35.7 "g"# of #"Br"_2# yields #40 "g"# of #"NaBr"#. What is the percentage yield?

##### 1 Answer

#### Explanation:

In order to work out the percentage yield of a reaction, we must use the following formula:

Now we must work out the theoretical yield of

We start by writing a balanced equation for the reaction

As we can see, the molar ratio of

Now that we have the balanced equation, we must work out how many moles we have of any reagent (in this case, sodium).

Moles can be worked out using this formula:

For sodium:

Now that we have the moles of sodium, we can work out the moles of sodium bromide. Since the molar ratio is

We have the moles and the atomic mass of

Finally, we can work out the percentage yield