Module 9 Review: Moles

What SI unit is used to measure the number of representative particles in a substance?

• kilogram

• ampere

• kelvin

• mole

Avogadro's number of representative particles is equal to

• 6.02 x 10²⁴

• 6.02

• 6.02 x 10²³

The following are equal to Avogadro's number EXCEPT

• the number of atoms of bromine in 1 mol Br₂

• the number of molecules of carbon monoxide in 1 mol CO

• the number of molecules of nitrogen in 1 mol N₂

• the number of atoms of gold in 1 mol Au

Which contains more atoms, a mole of silver atoms or a mole of gold atoms?

• silver

• gold

• they contain the same amount of atoms

Which has greater mass, a mole of silver atoms or a mole of gold atoms?

• silver

• gold

• the masses are the same

Which of the following is NOT true about molar mass?

• The molar mass is found by checking the periodic table and using the atomic weight.

• The molar mass is the mass of one mole of atoms.

• The molar mass is 12 g/mol for magnesium.

• The molar mass is the number of grams of an element that is numerically equal to the atomic mass in amu.

How many moles of hydrogen atoms are in one mole of methane (CH₄) molecules?

• A) 3

• B) 2

• C) 1

• D) 4

How many moles of oxygen atoms are contained in one mole of CaCO₃?

• 3

• 1

• 4

• 2

What is molar mass?

• the mass in grams of one mole of a substance

• the volume that one mole occupies

• molecules, atoms, or formula units

• the percent by mass of each element in a compound

What is true about the molar mass of a molecule of chlorine gas (Cl₂)?

• The molar mass is 71 g/mol

• The molar mass is equal to the mass of one atom of chlorine.

• The molar mass is 35.5 g/mol

• none of the above