What is the molar mass of ammonia, #"NH"_3#?
To determine the molar mass of any compound, all you have to do is add up the molar masses of every atom that makes up the respective compound.
In this case, you know that ammonia,
- one nitrogen atom,
- three hydrogen atoms,
This means that its molar mass will be the sum of the molar mass of one nitrogen atom and three times the molar mass of a hydrogen atom.
A quick look in the periodic table will show that you have
#"N: " "14.0067 g/mol"#
#"H: " "1.00794 g/mol"#
The molar mass of ammonia will thus be
#"14.0067 g/mol" + 3 xx "1.00794 g/mol" = color(green)("17.03052 g/mol")#