Chapter 8: Stoichiometry

Question 1

What do the coefficients in a stoichiometric equation mean?

Answer 1

They can mean molecules, atoms, or number of moles.

Question 2

Stoichiometry steps

Answer 2

1. Balance equation
2. Check for diatomic elements
3. Identify the Given + Find
4. Convert given → moles
5. Do a mole → mole ratio
   a. moles given x (LC of moles find/ LC of moles given)

Question 3

What are diatomic elements?

Answer 3

Elements composed of 2 atoms, ALWAYS GIVE EM A SUBSCRIPT OF 2.

Question 4

7 Diatomic elements?

Answer 4

HNOFClBri

Question 5

Stoichiometry Problem 1:
Given 5 moles of 2H20, find moles of oxygen.
2H20 → 2H2 + O

Answer 5

1. Balance equation
   a. 2H20 → 2H2 + O2
2. Check for diatomics.
3. Identify the Given + Find
   a. Given: 5 mol 2H2O
   b. Find: ? mol O2
4. Convert given → moles
5. Do a mole → mole ratio
   a. moles given x (LC of moles find/ LC of moles given)
   Answer: 2.5 mol O2.

Question 6

What’s the limiting reactant/ reagent?

Answer 6

The given substance that produces less of the desired product.

Question 7

Limiting Reagent steps?

Answer 7

1. Convert both to moles

2. Multiply by LC moles find/ LC moles given