Unit 8 Practice Test - The Mole

The simplest whole number ratio of the atoms present in a compound is its:

• molecular formula

• empirical formula

• formula unit

• molar mass

The molecular formula of a compound is the:

• formula showing actual ratio of atoms in the compound.

• formula showing the most simplified ratio of atoms in the compound.

• formula showing the ideal ratio of atoms in the compound.

• formula showing the theoretical ratio of atoms in the compound.

The mole is based on the mass of 12 grams of:

• hydrogen

• oxygen

• nitrogen

• carbon

What is the mass of one mole of (NH₄)₂SO₃?

• 144 g

• 138 g

• 116 g

• 78 g

What is the molecular formula of a compound with the empirical formula CH₂O and molecular mass of 360 grams?

• C₉H₁₈O₉

• C₁₂H₂₄O₁₂

• C₆H₁₂O₆

• C₂H₄O₂

Avogadro's number of Boron (B) atoms would have a mass of:

• 6.02 x 10^-23 grams

• 6.02 x 10²³ grams

• 10.8 grams

• 6 grams

One mole of Aluminum contains:

• 51.97 x 10²³ atoms

• 2.06 x 10²³ atoms

• 6.02 x 10²³ atoms

• 12.04 x 10²³ atoms

How many moles are present in 19.82 g Mg?

• 0.8156 moles

• 1.000 moles

• 1.226 moles

• 481.7 moles

How many moles are equal to 1.0 x 10²⁴ atoms of Gallium?

• 0.66 mole

• 1 mole

• 1.66 mole

• 6.02 mole

How many molecules of CO₂ are present in 4 g of CO₂?

• 1.83 x 10²³

• 5.06 x 10²³

• 5.42 x 10²²

• 3.55 x 10²⁶