What is the molar mass of phosphorus?

1 Answer
May 22, 2017

#123.88 "g"/"mol"#

Explanation:

Step 1. Determine how many of each type of atom there are in the chemical formula #"P"_4#

#" "#In this case, there are 4 phosphorous atoms per molecule

Step 2. Determine the mass of phosphorous from the periodic table
ptable.com
Because the atomic mass of phosphorous is 30.97 amu, we can say the mass is

#m=4xx30.97=123.88 "g"/"mol"#

This means that 1 mol of #"P"_4# weighs 123.88 grams.

[NOTE: If you only wanted the molar mass of single atoms of phosphorous, then #m=30.97 "g"/"mol"#; That is a mole of isolated phosphorous atoms would weigh 30.97 grams.]