What is the mass of hydrogen in "72.0 g CH"_4"72.0 g CH4?

1 Answer
Aug 3, 2017

There are "53.9 g C"53.9 g C and "18.1 g H"18.1 g H in "72.0 g CH"_472.0 g CH4.

Explanation:

The chemical formula for methane is "CH"_4CH4. 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"16.043 g/mol, which means that one mole of methane has a mass of "16.043 g"16.043 g.

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

In order to determine the mass of carbon in "72.0 g CH"_4"72.0 g CH4, multiply the given mass of methane by the inverse of its molar mass to get moles "C"C, then multiply by the molar mass of carbon in methane to get mass of "C"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"