Question

If the theoretical yield for a chemical reaction is 100. g and the percentage yield is 70.0%, what is the actual yield?

Answer 1

`"70.0 g"`

Explanation:

The actual yield is a term used to describe the amount of product that is actually produced by a given chemical reaction.

By comparison, the theoretical yield is a term we use to denote the amount of product that could be produced by a given chemical reaction.

In other words, the theoretical yield corresponds to the case in which a reaction produces the maximum amount of a product given a certain amount of reactants.

Now, the percent yield is a measure of the difference between what we could get and what we actually get. Simply put, a reaction's percent yield tells us how much product we actually get for every `"100 g"` of product that we could theoretically get.

`color(blue)(ul(color(black)("% yield" = "what we actually get"/"what we could theoretically get" xx 100%)))`

In this case, you know that the theoretical yield for given reaction is equal to `"100. g"` and that its percent yield is equal to `70.0%`.

This means that for every `"100 g"` of product that could theoretically be produced, we only get `"70.0 g"`.

Therefore, you can say that the actual yield is equal to

`color(darkgreen)(ul(color(black)("actual yield = 70.0 g")))`

Notice that you get the same result by using the equation

`70.0% = "actual yield"/"100. g" xx 100%`

Rearrange to find

`"actual yield" = (70.0 color(red)(cancel(color(black)(%))) * color(blue)(cancel(color(black)(100.))) "g")/(color(blue)(cancel(color(black)(100.)))color(red)(cancel(color(black)(%)))) = color(darkgreen)(ul(color(black)("70.0 g")))`

The answer is rounded to three sig figs.