Calculate the percentage composition of sulphuric acid if the atomic masses are H=1u, S=32u and 0=16u

Answer 1

The formula for sulphuric acid is H2SO4. So, first you add up the masses of all the components in the formula.

2 hydrogens = 1u * 2 = 2u
+
1 sulphur = 32u
+
4 oxygens = 16u * 4 = 64u
=
98u

98u is the mass of the compound, I'm not sure which element you are trying to find the percent composition of.

Once you have the element you are trying to find the percent composition of, you find that element's mass in the compound, divide it by the total (98u), and then multiply by 100 to get the percent.

For example, if you wanted the percent composition of hydrogen you would do:

2u/98u = 0.0204 * 100 = 2.0%

Hope this helps!

Answer 2

Note: When the question asks for percent composition of a compound, it means to find the percent of EACH element in the compound.