Magnesium chloride has an atomic mass of 94 amu. What is the mass of one mole of magnesium chloride?

1 Answer
Jun 21, 2018

#"94 g"#!

Explanation:

If #1# particle of #MgCl_2# has a mass of #"94 amu"#, then #1# mole of #MgCl_2# will have a mass of #"94 g"#.

It might seem weirdly convenient that these are the same value at first, but the mole was actually defined for this exact purpose!—to easily relate things from the macroscopic and atomic worlds.

One mole is defined as the number of atoms in #"12 g"# of #"carbon-12"#, one atom of which has a mass of #"12 amu"#.

#"1 mole of atoms" = "12 g"/"12 amu"#

This definition effectively establishes this ratio:

#"amu"/"atom" = "grams"/"mole"#