Converting between Moles, Atoms, and Molecules (Part 2)

What does Avogadro's number (6.02 x 10^23) represent in chemistry?

• The number of grams in one mole of any substance.

• The number of particles (atoms, molecules, etc.) in one mole of any substance.

• The volume of one mole of any gas at STP.

• The charge of an electron.

How many molecules are present in 0.63 moles of a substance?

• 3.79 x 10^23 molecules

• 3.8 x 10^23 molecules

• 6.02 x 10^23 molecules

• 0.63 molecules

To convert 0.63 moles of molecules into the number of molecules, which conversion factor should be used?

• (1 mole / 6.02 x 10^23 molecules)

• (6.02 x 10^23 molecules / 1 mole)

• (12 molecules / 1 dozen)

• (1 mole / 12 molecules)

A sample contains 3.9 x 10^20 Magnesium atoms. How many moles of Magnesium atoms are in the sample?

• 6.48 x 10^-4 moles

• 6.5 x 10^-4 moles

• 3.9 x 10^20 moles

• 6.02 x 10^23 moles