Mastering 2 Step Mole Conversions in Chemistry

What is the first step in any two-step unit conversion problem?

• Convert to grams

• Convert to moles

• Convert to particles

• Convert to liters

Which number is used to convert atoms of sodium to moles of sodium?

• 22.4

• 74.10

• 6.022 x 10^23

• 32.00

What is the molar mass of sodium used in the conversion from moles to grams?

• 16.00

• 74.10

• 32.00

• 22.99

In the example problem, what is the final mass of sodium obtained from 5.63 x 10^21 atoms?

• 0.2130 grams

• 0.2150 grams

• 0.2149 grams

• 0.2160 grams

What is the molar mass of calcium hydroxide used in the example problem?

• 74.10

• 16.00

• 32.00

• 22.99

How many significant figures should the final answer have in the example problem involving calcium hydroxide?

• 1

• 2

• 3

• 4

What is the volume of one mole of gas at STP?

• 16.00 liters

• 74.10 liters

• 22.4 liters

• 32.00 liters

What is the molar mass of O2 used in the conversion from moles to grams?

• 74.10

• 16.00

• 32.00

• 22.99

What should you always include when writing your final answer in unit conversion problems?

• Only the number

• Only the unit

• Both the number and the unit

• None of the above

What is a common mistake to avoid when using scientific notation in mole conversions?

• Using the wrong molar mass

• Not converting to moles first

• Using too many significant figures

• Forgetting to use parentheses