Molar Mass and Chemical Formulas

The video tutorial explains how to calculate the molar mass of potassium dichromate (K2Cr2O7). It begins by identifying the elements involved: potassium, chromium, and oxygen. The tutorial then uses the periodic table to find the atomic masses of these elements and calculates the total molar mass by multiplying the atomic masses by the number of atoms present in the compound. The final molar mass is determined by summing these values, resulting in 294.00 grams per mole. The video concludes with an explanation of what this molar mass means in practical terms.

What is the chemical formula for potassium dichromate?

• K2Cr2O7

• KCr2O7

• K2CrO4

• KCrO4

Which element in potassium dichromate has an atomic mass of 39.10 grams per mole?

• Potassium

• Oxygen

• Hydrogen

• Chromium

How many chromium atoms are present in one molecule of K2Cr2O7?

• Two

• Three

• Four

• One

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

• 12.01 grams per mole

• 14.01 grams per mole

• 16.00 grams per mole

• 18.00 grams per mole

How do you calculate the total molar mass of K2Cr2O7?

• Multiply the atomic masses by the number of atoms and sum them up

• Subtract the atomic masses of oxygen from the total

• Add the atomic masses of all elements

• Divide the atomic masses by the number of atoms

What is the total molar mass of potassium dichromate?

• 310.00 grams per mole

• 294.00 grams per mole

• 250.00 grams per mole

• 280.00 grams per mole

If you have 294.00 grams of K2Cr2O7, how many moles do you have?

• 3 moles

• 2 moles

• 1 mole

• 0.5 moles

What does the molar mass of a compound represent?

• The volume of the compound

• The density of the compound

• The mass of one mole of the compound

• The number of atoms in a molecule