Stoichiometry Problem Lesson

Stoichiometry Lesson #1

Stoichiometry is a fundamental method of converting units in chemical reactions in chemistry.

Multiple Choice

I have 5 eggs, how many cookies can I make? (assume there is enough of every other ingredient)

• 2 dozen cookies

• 5 dozen cookies

• 12.5 dozen cookies

• 2.5 dozen cookies

Multiple Choice

In a balanced chemical equation, coefficients represent ___.

• subscripts

• atoms

• grams

• moles

Multiple Choice

2KClO₃ --> 2KCl + 3O₂

How many moles of oxygen (O₂) can be produced from the decomposition of 15.0 moles of potassium chlorate (KClO₃)?

• 3.00 moles

• 1.50 moles

• 10.00 moles

• 22.5 moles

Multiple Choice

2H₂O --> 2H₂ + O₂

How many grams of hydrogen (H₂) could be produced from the decomposition of 25.0 moles of water (H₂O)?

• 101 grams

• 50.5 grams

• 2.02 grams

• 48.48 grams

The FIRST question you should always ask when solving a stoichiometry problem is...

IS THE KNOWN VALUE IN MOLES???

If it is NOT in moles, convert it to moles!!!

Multiple Choice

4NH₃ + 5O₂ --> 4NO + 6H₂O

How many moles of NH₃ are required to produce 40.0 grams of NO?

The FIRST step in this problem is to...

• panic because I will never understand this stuff

• convert 40.0 grams NO to moles of NO

• convert 40.0 grams of NO to moles of NH₃

• convert 40.0 grams of NO to moles of H₂O

Multiple Choice

2 KClO₃ → 2 KCl + 3 O₂

How many moles of oxygen are produced when 6.7 moles of KClO₃ decompose completely?

• 6.7 mol

• 1.0 mol

• 10.1 mol

• 4.5 mol

Multiple Choice

2 NaClO₃ (s) --> 2NaCl (s) +3 O₂ (g)  
12.00 moles of NaClO₃ will produce how many grams of O₂?

• 256 g of O₂
• 576 g of O₂
• 288 g O₂

Multiple Choice

Using the following equation:

Fe₂O₃(s) + 3H₂(g) → 2Fe(s) + 3H₂O(l)

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

• 4 moles Fe

• 6 moles Fe

• 9 moles Fe

• 2 moles Fe

Multiple Choice

What is the mole ratio in the following reaction:

2CO + O₂ → 2CO₂

• 2:1:2

• 1:1:1

• 1:2:1

• Have no clue what a mole ratios is!!

Multiple Choice

How many particles are in a mole?

• 602

• 602 million

• 602 moles

• 6.02 x 10²³

Multiple Choice

How many moles are in 19.82 g Mg?

• 1.226mol Mg

• 481.7mol Mg

• 1.000mol Mg

• 0.82 mol Mg