What is the mass of hydrogen in #"72.0 g CH"_4"#?

1 Answer
Aug 3, 2017

Answer:

There are #"53.9 g C"# and #"18.1 g H"# in #"72.0 g CH"_4#.

Explanation:

The chemical formula for methane is #"CH"_4#. This means that in one mole of methane, there is one mole of carbon and four moles of hydrogen.

The molar mass of methane is #"16.043 g/mol"#, which means that one mole of methane has a mass of #"16.043 g"#.

The molar mass of carbon is #"12.011 g/mol"#, which means that one mole of methane contains #"12.011 g C"#.

In order to determine the mass of carbon in #"72.0 g CH"_4"#, multiply the given mass of methane by the inverse of its molar mass to get moles #"C"#, then multiply by the molar mass of carbon in methane to get mass of #"C"#.

#72.0color(red)cancel(color(black)("g CH"_4))xx(1color(red)cancel(color(black)("mol CH"_4)))/(16.043color(red)cancel(color(black)("g CH"_4)))xx(12.011"g C")/(1color(red)cancel(color(black)("mol CH"_4)))="53.9 g C"#

In order to determine the mass of hydrogen in #"72.0 g CH"_4"#, subtract the mass of carbon from the given mass of methane.

#"72.0 g CH"_4-"53.9 g C"="18.1 g H"#