Molar Mass and Chemical Formulas

This video tutorial explains how to calculate the molar mass of magnesium chloride hexahydrate (MgCl2·6H2O). It begins by determining the molar mass of magnesium chloride (MgCl2) using the periodic table values for magnesium and chlorine. Then, it calculates the molar mass of six water molecules (H2O) and combines these values to find the total molar mass of MgCl2·6H2O. The video concludes with a note on rounding based on the periodic table's decimal points.

What is the chemical formula for magnesium chloride hexahydrate?

• MgCl2·6H2O

• MgCl2·H2O

• MgCl·6H2O

• Mg2Cl·6H2O

What is the molar mass of magnesium (Mg) as found on the periodic table?

• 1.01 grams per mole

• 16.00 grams per mole

• 35.45 grams per mole

• 24.31 grams per mole

How many chlorine atoms are present in magnesium chloride (MgCl2)?

• Three

• One

• Four

• Two

What is the molar mass of a single water molecule (H2O)?

• 18.02 grams per mole

• 35.45 grams per mole

• 16.00 grams per mole

• 1.01 grams per mole

How many water molecules are associated with magnesium chloride in MgCl2·6H2O?

• Eight

• Two

• Four

• Six

What is the total molar mass of MgCl2·6H2O?

• 95.21 grams per mole

• 203.33 grams per mole

• 108.12 grams per mole

• 24.31 grams per mole

Why might your calculated molar mass differ slightly from others?

• The number of water molecules might be different.

• Different periodic tables may round to different decimal points.

• The chemical formula might be incorrect.

• The atomic mass of magnesium might be different.

Who is the presenter of the video?

• Dr. B

• Dr. A

• Dr. D

• Dr. C