A student sets up a reaction and calc a possible yield of 55.9 grams of silver. If the student performs the reaction and the mass of actual silver obtained is 42.5 grams. What is the percent yield?

1 Answer
Aug 17, 2016

#"% yield" = 76.0%#


A chemical reaction's percent yield basically tells you how many grams of product you get for every #"100 g"# of product you could theoretically get.

The theoretical yield is calculated by taking into account the stoichiometry of the reaction and the actual yield is measured after the reaction is finished.

In your case, a given reaction's stoichiometric calculations tell you that you can theoretically produce #"55.9 g"# of silver.

However, you perform the reaction and you collect #"42.5 g"# of silver. In order to find the reaction's percent yield, use the information given to calculate how much silver you'd get for a theoretical yield of #"100 g"# of silver

#100 color(red)(cancel(color(black)("g theoretical"))) * "42.5 g actual"/(55.9color(red)(cancel(color(black)("g theoretical")))) = "76.0 g actual"#

So, if the reaction produces #"76.0 g"# of silver for every #'100 g"# of silver it could theoretically produce, you can say that its percent yield is equal to

#color(green)(|bar(ul(color(white)(a/a)color(black)("% yield" = 76.0%)color(white)(a/a)|)))#

The answer is rounded to three sig figs.