Complete the following table: (In this problem you are to determine the values for each of the empty entries. The goal of this problem is for you to become comfortable with the moles, molar mass, and Avogadro's number. If you would like some help use the Help table below. To check your answers use the Answer table.)

ANSWER Table:

Formula

M, Molar
Mass (g ­ mol-1)

m, Mass of
sample (g)

n, Moles of
sample (mol)

N, Number of atoms,
molecules or formula units

Mo

 

 

 

 

62.8

Answer:The formula Mo, stands for molybenum, the atomic mass is 95.9 u, so the molar mass is 95.9 g ­ mol-1.

Formula

M, Molar
Mass (g ­ mol-1)

m, Mass of
sample (g)

n, Moles of
sample (mol)

N, Number of atoms,
molecules or formula units

Mo

95.9

 

 

62.8

At this point the mass of the sample or the number of atoms of the sample can be calculated. Either one can be done first. We'll start by converting the moles of the sample to the mass of the sample using the molar mass ( 95.9 g = 1 mol)

Formula

M, Molar
Mass (g ­ mol-1)

m, Mass of
sample (g)

n, Moles of
sample (mol)

N, Number of atoms,
molecules or formula units

Mo

95.9

6.02 x 103

62.8

Converting moles to atoms is accomplished using Avogadro's number,

6.02 x 1023 atoms = 1 mol Mo

Beginning with the number of moles of molybdenum and using the conversion from moles to atoms we get,