Unit 7 Review (E-Learning Day)

The Mole & Gram to mole conversions

THE MOLE

• A unit of Measure

• Easier then measuring each individual particle

• Equal to the Molar Mass of each element or compound

• Ex: 12.011grams Carbon = 1 Mole

Multiple Choice

What is the molar mass of Oxygen?

• 8 grams

• 8 moles

• 15.999 grams

• 15.999 moles

Multiple Choice

What is the molar mass of Hydrogen?

• 2 moles

• 2 grams

• 1.008 moles

• 1.008 grams

Gram To Mole Conversion

• Always starting with the amount of grams given in the problem.

• Use the conversion factor 1 mole over the Atomic mass (molar mass) of the element or compound.

Multiple Choice

How many moles is 4 grams of silicon?

• 4 moles

• 0.14 moles

• 28.085 moles

• 1.4 moles

Multiple Choice

How many moles is 19.5 grams of Sodium?

• 19.5 moles

• 0.85 moles

• 22.99 moles

• 8.5 moles

Calculating Molar Mass of a Compound

• Determine the number of atoms of each element

• Multiply the number of atoms by the atomic mass of each element

• Add the molar masses of each element together for the molar mass of the compound

Multiple Choice

Calculate the Molar Mass of MgO?

• 40.305 gram

• 24.305 gram

• 15.999 gram

• 39 gram

Multiple Choice

Calculate the Molar Mass of AlBr₃?

• 106.886 grams

• 266.694 grams

• 26.982 grams

• 79.904 grams

Multiple Choice

How many moles is 78 grams of Li₃N?

• 34.827 moles

• 2.24 moles

• 78 moles

• 20.82 moles

Multiple Choice

How many moles is 100 grams of FeCl₂?

• 0.79 moles

• 100 moles

• 126.745 moles

• 7.9 moles

1 3

3 2

1 2

1 mole N2 = 3 moles H2

Multiple Choice

How many moles of hydrogen are needed to react with 2 moles of nitrogen?

N₂ +  3 H₂ → 2 NH₃ 

• 6

• 2

• 3

• 1

Multiple Choice

How many moles of iron can be made from 6 moles H₂? 

Fe₂O₃ + 3 H₂ → 2 Fe + 3 H₂O

• 4 moles Fe

• 6 moles Fe

• 9 moles Fe

• 2 moles Fe