Molar Mass and Atomic Structure

The video tutorial explains how to calculate the molar mass of phosphorus trichloride (PCl3). It begins by identifying the molar mass of phosphorus and chlorine using the periodic table. The tutorial then demonstrates how to multiply the molar mass of chlorine by three, as there are three chlorine atoms in PCl3, and adds this to the molar mass of phosphorus. The final molar mass of PCl3 is calculated to be 137.32 grams per mole. The video concludes by explaining the significance of this calculation in terms of moles and grams.

What is the atomic mass of phosphorus as found on the periodic table?

• 1.008 grams per mole

• 137.32 grams per mole

• 35.45 grams per mole

• 30.97 grams per mole

How many chlorine atoms are present in a molecule of PCl3?

• Three

• Four

• Two

• One

What is the atomic mass of chlorine used in the calculation?

• 1.008 grams per mole

• 35.45 grams per mole

• 137.32 grams per mole

• 30.97 grams per mole

What is the total molar mass of PCl3?

• 30.97 grams per mole

• 35.45 grams per mole

• 137.32 grams per mole

• 1.008 grams per mole

If you have 137.32 grams of PCl3, how many moles do you have?

• One mole

• Three moles

• Two moles

• Four moles

What does the molar mass of a compound represent?

• The density of the compound

• The volume of the compound

• The mass of one mole of the compound

• The number of atoms in a molecule