Chemical Reactions & Molar Quantities

A mole is a large number used to simplify the counting of atoms.

• True

• False

Tags

NGSS.HS-PS1-7

The molar mass of Na₂S is ______.

• 78.04 g

• 55.05 g

• 60.09 g

• 46.08 g

The number of representative particles in a mole (6.02 × 10²³) is called Avogadro’s number.

• True

• False

Particles counted by moles can only be atoms.

• True

• False

A sample of carbon has a mass of 6.0 grams. What number of moles are contained in this sample?

• 1.5 moles

• 0.5 moles

• 2.0 moles

• 1.0 moles

Calculate the mass of 2.0 moles of aluminum (Al)

• 26.98 g

• 53.96 g

• 13.0 g

• 200.00 g

How many moles of gold (Au) are there in a sample of gold that weighs 300.0 g?

• 1.52 moles

• 2.50 moles

• 0.65 moles

• 3.75 moles

How many moles of carbon are there in a carbon sample of mass 30.0 g?

• 2.50 moles

• 1.25 moles

• 1.00 moles

• 0.40 moles

An aluminum can has a mass of 9.45 grams. How many moles of aluminum are used to make this can?

• 0.25 moles

• 0.15 moles

• 0.35 moles

• 0.45 moles

What is the number of moles of Calcium in a sample of Calcium that is found to weigh 120.24 g?

• 2 moles

• 1 mole

• 3 moles

• 4 moles