Question

The theoretical yield of a reaction is 82.5 grams, but the reaction actually yields 12.3 grams less than expected. What is the percent yield for this reaction?

Answer 1

`85.1%`

Explanation:

Percent yield is defined as the ratio between the actual yield and the theoretical yield of the reaction, multiplied by `100`

`color(blue)(|bar(ul(color(white)(a/a)"% yield" = "what you actually get"/"what you should theoretically get" xx 100 color(white)(a/a)|)))`

So, you know that your reaction has a theoretical yield of `"82.5 g"`. This means that if all the moles of reactants that take part in the reaction end up producing moles of product according to the reaction's stoichiometric coefficients, you will get `"82.5 g"` of product.

In other words, the theoretical yield tells you how much product is produced for a `100%` yield.

Now, the reaction is said to produce `"12.3 g"` less than expected. This means that you only collected

`"actual yield" = "82.5 g" - "12.3 g" = "70.2 g"`

The reaction's percent yield will thus be

`"% yield" = (70.2 color(red)(cancel(color(black)("g"))))/(82.5color(red)(cancel(color(black)("g")))) xx 100 = color(green)(|bar(ul(color(white)(a/a)"85.1%"color(white)(a/a)|)))`

The answer is rounded to three sig figs.