Unit 5 - Review

Which of the following is NOT true about one mole?

• One mole contains 6.02 x 10²³ particles.

• The mass of 1 mole of carbon atoms = the mass of 1 mole of boron atoms.

• about 12 grams of carbon equals 1 mole of carbon atoms.

• None of the above are true

A bunch of nails have a mass of 3.05 grams. How many moles of iron do they contain?

• 0.00983 moles

• 0.547 moles

• 0.00547 moles

• 0.983 moles

A student needs to use 0.575 moles of sodium chloride (NaCl) in an experiment. How many grams should they mass out?

• 33.6 grams

• 66.3 grams

• 0.00983 grams

• 0.00663 grams

If 0.0312 moles of calcium is created in a beaker during an experiment, how many atoms are there in the beaker?

(HINT: 1 mole = 6.02 x 10²³ atoms)

• 5.18 x 10²² atoms

• 1.25 x 10²² atoms

• 1.88 x 10²² atoms

• 6.11 x 10²² atoms

Suppose that you mass out 3.50 grams of Na₂CO₃. How many moles would you have?

• 0.0330 moles

• 371 moles

• 352 moles

• 0.0433 moles

Suppose that you need to find the molar mass of Na₂CO₃ in an experiment. What is the molar mass?

• about 110 g/mole

• about 100 g/mole

• about 106 g/mole

• about 96 g/mole

What are the units for Molar Mass?

• moles

• grams

• mole/gram

• gram/mole

What is the Molar Mass of BF₃?

• about 10.8 g/mole

• about 57 g/mole

• about 35 g/mole

• about 162 g/mole

True or false: element's molar masses were originally based on the relative mass of helium.

• True

• False

True or false: Element's molar masses were originally based on their relative mass in relation to hydrogen.

• True

• False