What is the percentage composition of a compound containing 32.0 g of bromine and 4.9 g of magnesium?

1 Answer
Mar 18, 2016

Answer:

The percent composition of bromine is #86.7%#, and the percent composition of magnesium is #13.3%#.

Explanation:

In order to determine the percent composition of an element in a given sample of a compound, divide the mass of the element in the sample by the total mass of the sample and multiply by 100.

The given compound is magnesium bromide #("MgBr"_2")#. The total mass of the sample of #"MgBr"_2"# is:

#"32.0 g Br+4.9 g Mg"="36.9 g MgBr"_2"#.

#% "composition Br"=(32.0 cancel"g")/(36.9 cancel"g")xx100="86.7%"#

#% "composition Mg"=(4.9 cancel"g")/(36.9 cancel"g")xx100=13.3%"#

Check: #86.7%+13.3%=100.0%#