Mole and Avogadro's Number

What is the definition of a mole?

• A mole is the amount of a substance that contains the same number of entities as there are atoms in 12 grams of pure carbon-12.

• A mole is a small burrowing mammal with velvety fur and a pink snout.

• A mole is a type of skin blemish caused by the overgrowth of skin cells.

• A mole is a unit of measurement used to count the number of molecules in a substance.

How do you calculate the molar mass of a compound?

• Multiply the atomic number by the number of atoms in the compound

• Divide the molecular weight by the number of moles

• Calculate the atomic mass of each element in the compound and then add them together to get the molar mass of the compound.

• Subtract the atomic mass of each element in the compound

What is Avogadro's number?

• 5.022 x 10^23

• 7.022 x 10^23

• 6.022 x 10^23

• 6.022 x 10^22

Tags

NGSS.HS-PS1-7

Explain the relationship between mole and volume in a gas at STP.

• The relationship between mole and volume in a gas at STP is that one mole of any gas occupies a volume of 10 liters

• The relationship between mole and volume in a gas at STP is that one mole of any gas occupies a volume of 22.4 liters.

• One mole of any gas occupies a volume of 1 liter at STP

• The volume of a gas at STP is not related to the number of moles present

How is the mole concept used in empirical formulas?

• The mole concept is used to determine the relative number of atoms or molecules in a compound, which is essential for calculating empirical formulas.

• The mole concept is used to measure the volume of a compound, which is essential for calculating empirical formulas.

• The mole concept is used to determine the color of a compound, which is essential for calculating empirical formulas.

• The mole concept is used to calculate the density of a compound, which is essential for calculating empirical formulas.

Tags

NGSS.HS-PS1-7

If the molar mass of a substance is 40 g/mol, how many moles are present in 160 grams of the substance?

• 4 moles

• 6 moles

• 2 moles

• 10 moles

What is the molar mass of water (H2O)?

• The molar mass of water (H2O) is 18.02 g/mol.

• The molar mass of water (H2O) is 25.50 g/mol.

• The molar mass of water (H2O) is 20.00 g/mol.

• The molar mass of water (H2O) is 16.00 g/mol.

How many atoms are present in 1 mole of carbon?

• 7.5 x 10^23 atoms

• 6.022 x 10^23 atoms

• 1 x 10^23 atoms

• 5.022 x 10^23 atoms

What is the volume occupied by 1 mole of any gas at STP?

• 22.4 liters

• 15.0 liters

• 30.0 liters

• 10.0 liters

If the empirical formula of a compound is CH2O and its molar mass is 90 g/mol, what is its molecular formula?

• CH3O2

• C2H4O2

• CHO

• CH2O