Chapter 8 - Molar Conversions Part 2

Chapter 8 - Molar Conversions Part 2

by Lynda Leibowitz

Now that you know how to do molar conversions with an element, let's give it a try with compounds.​

The main difference is going to be the need to calculate the molar mass.​

Practice calculating molar mass by answe​ring the following questions.

Multiple Choice

What is the molar mass of table salt (NaCl)?

• 116.886 g/mol
• 35.453 g/mol
• 22.990 g/mol
• 58.443 g/mol

Multiple Choice

What is the molar mass of CO₂?

• 12
• 16
• 32
• 44

Multiple Choice

Calculate the molar mass of Ba(C₂H₃O₂)₂

• 255.3 g/mol

• 237.3 g/mol

• 228.3 g/mol

• 196.3 g/mol

Multiple Choice

Calculate the molar mass of NH₄NO₂

• 50 g/mol

• 60 g/mol

• 64 g/mol

• 78 g/mol

Now that you ​recall how to calculate molar mass we will do molar conversions with compounds.

REMEMBER --> Now if you are using the flowchart to multiply or divide by molar mass you will need to calculate it first!!​

Here is the flowchart again. Please use your copy to answer the following questions.​

Multiple Choice

What is the mass of 6.25 mol of Cu(NO₃)₂?

• 126 g

• 785 g

• 625 g

• 1172 g

Multiple Choice

What is the mass of 2.50 mol of oxygen gas O₂?

• 40.0 g
• 80.0 g
• 16.0 g
• 32.0 g

Multiple Choice

How many grams are in 3.3 mol of Potassium Sulfide, $$K_2S$$  ?

• 360 g
• 454 g
• 238 g
• 132 g

Multiple Choice

How many moles are in 20 grams of CaO?

• 0.357

• 0.56

• 1.22

• 20

Multiple Choice

How many atoms are there in 67.2 grams of lead (II) chloride, $$PbCl_2$$  ?

• $$3.11\ x\ 10^{24}$$  

• $$1.45\ x\ 10^{23}$$  

• $$6.02\ x\ 10^{23}$$  

• $$5.52\ x\ 10^{23}$$  

Multiple Choice

If I have 9.88 x 10²³ atoms of CO₂, what is the mass?

• 44.0 g

• 2.65 x10²³ g

• 1.37 x10²² g

• 72.2 g

Multiple Choice

How many atoms of carbon are in 6.00g of carbon?

• 1.20x10²⁴atoms C
• 6.02x10²³atoms C
• 3.01x10²³atoms C
• 1.50x10²³atoms C

Multiple Choice

How many grams are in 1.2 x 10²⁴ molecules of carbon monoxide, CO?

• 28 grams
• 56 grams
• 6.02 grams
• 1.2 grams

Multiple Choice

What is the mass of 0.89 mol of CaCl₂?

• 111 grams
• 0.008 grams
• 98.9 grams
• none of the choices

Multiple Choice

True or False: One mole of Sulfur has 2.35 x 10¹⁴ atoms.

• True

• False

Multiple Choice

How many moles are in 50 grams of Calcium Bromide, CaBr₂?

• 0.75

• 1.25

• 0.25

• 0.55