Math quiz practice

What is the total number of moles of hydrogen atoms contained in 1 mole of 2(NH₄)₂C₂O₄?

• 8

• 16

• 2

• 4

What is the total number of atoms present in 3Mg₂(NO3)₂?

• 5

• 10

• 8

• 30

The ratio of Iron to sulfur is Al₂O₃, is

• 2 grams of Aluminum to 3 grams of Oxygen

• 3 grams of Aluminum to 2 grams of Oxygen

• 2 moles of Aluminum to

  3 moles of Oxygen

• 3 moles of Aluminum to 2 moles of Oxygen

What is the total number of oxygen atoms in the formula MgSO₄ • 7 H₂O?

• 11

• 7

• 5

• 4

The formula mass of a compound is the

• products of the atomic numbers of its atoms

• sum of the atomic numbers of its atoms

• sum of the atomic masses of its atoms

• product of the atomic masses of its atoms

The molar mass of Ba(OH)₂ is

• 154.3 g

• 171.3 g

• 155.3 g

• 308.6 g

The total number of moles represented by 2.0 grams of CaCO₃ is

• 0.02

• 0.1

• 2

• 1

What is the number of moles of CO₂ in a 220.-gram sample of CO₂

(gram-formula mass = 44 g/mol)?

• .20 moles

• 15 moles

• 5.0 moles

• 44 moles

What is the mass in grams of 2.00 mole of O₂ gas?

• 64grams

• 32 grams

• 16 grams

• 11.2 grams

What is the percent composition by mass of sulfur in the compound MgSO₄ (gram-formula mass = 120. grams per mole)?

• 46 %

• 27 %

• 53%

• 46%