What is the percentage composition by mass of nitrogen in ammonia?

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Answer 1 · 2017-08-30T06:58:47

Well it is simply #"Mass of nitrogen"/"Mass of nitrogen and hydrogen"xx100%#

And thus taking molar masses......we get:

#(14.01*g*mol^-1)/(14.01*g*mol^-1+3xx1.00794*g*mol^-1)xx100%#

#~=80%#

Answer 2 · 2017-08-30T07:02:46

The mass percent of #"N"# in #"NH"_3# is #82.244%#.

Divide the mass of #"N"# by the mass of #"NH"_3#, then multiply by #100#

The chemical formula for ammonia is #"NH"_3#. The formula indicates that in each mole of #"NH"_3#, there is one mole of #"N"# atoms.

The molar mass of ammonia is #"17.031 g/mol"#. The molar mass of #"N"# is #"14.007 g/mol"#.

#"mass percent N"##=##(14.007color(red)cancel(color(black)("g/mol")))/(17.031color(red)cancel(color(black)("g/mol")))xx100="82.244%"#