Check your answer...do you agree? Great if you do. If you do not check the Solution: below the table to see how the molar mass of the unknown is determined.

The next answer is the number of atoms, molecules or formula units. Try to determine the value before clicking on the link.

Solution:

In this case, unlike the previous examples, the formula of the substance is unknown. So the periodic table can not be use. So how do we determine the molar mass if we have no idea what the substance is? All we have to do is remember the units on molar mass are grams per mol. We are given the mass of the sample AND how many moles the particular mass is equal to, so all we have to do is set up the quotient and divide. The molar mass is;

This particular approach is very important and we will encounter it a little bit later this semester.