Stoichiometry Basics Review

Stoichiometry Basics Review

Counting Atoms

• For an atom, recall they all START with a capitol letter

• If a lower case letter follows, that is the same atom

• if another upper case letter follows that is a new atom

Counting atoms

• If there is a subscript, that applies to ONLY the atom that it is with

• If there is a coefficeint, that applies to the WHOLE molecule

• If there are parenthesis followed by a subscript, the subscript applies to everything in the parentheses

Counting atoms continued

• if you are looking for atoms in the entire molecule, count them and just add them up!

• 
  

• 
  

Multiple Choice

How many Oxygen are in H₂O?

• 1
• 2
• 0
• 4

Multiple Choice

How many atoms are there TOTAL in H₂SO₄ ?

• 6

• 5

• 7

• 3

Multiple Choice

4CF₂Cl₂

• C = 4, F = 4, Cl = 2

• C = 1, F = 8, Cl = 8

• C = 4, F = 8, Cl = 8

• C = 1, F = 4, Cl = 8

Multiple Choice

How many Sodium (Na) are in 6NaCl?

• 1
• 12
• 6

Multiple Choice

Number of N in (NH₄)₂CrO₄

• 1
• 2
• 8
• 16

Multiple Choice

How many Sodium (Na) are in 6NaCl?

• 1
• 12
• 6

Multiple Choice

How many Magnesium are in 10MgCl₂?

• 10

• 5

• 20

Multiple Choice

How many atoms are in Al₂(SO₄)₃

• 4

• 12

• 17

• 24

Multiple Choice

How many atoms are in this compound?... NaHCO₃

• 3

• 4

• 5

• 6

Multiple Choice

C₁₂H₂₂O₁₁ has how many total atoms?

• 3

• 11

• 35

• 45

Multiple Choice

How many total atoms are in the compound C₂H₈O ?

• 2

• 10

• 11

• 3

Multiple Choice

How many Hydrogen are in 4H₂O?

• 6

• 8

• 2

• 4

When determining if an equation is balanced or not-

• count the number of atoms on each side

• is it balanced??

Multiple Choice

2 KNO₃ + H₂CO₃ → K₂CO₃ + 2 HNO₃

• Balanced
• Not Balanced

Multiple Choice

2 AgI + Na₂S → Ag₂S + 2 NaI

• Balanced
• Not Balanced

Multiple Choice

4AgI + Na₂S → AgS + 3NaI

• Balanced
• Not Balanced

Multiple Choice

Ca + O₂ --> CaO

Is this reaction balanced?

• Yes

• No

• Maybe

Multiple Choice

PCl₅ + 4 H₂O → H₃PO₄ + 5 HCl

• Balanced
• Not Balanced

Multiple Choice

C₂H₆O + 3 O₂ → 2 CO₂ + 3 H₂O

• Balanced
• Not Balanced

Multiple Choice

CO₂ + H₂O → C₆H₁₂O₆ + 6H₂O₂

• Balanced
• Not Balanced

Multiple Choice

6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂

• Balanced
• Not Balanced

Multiple Choice

Is the following equation balanced or unbalanced?
Fe + S --> FeS

• balanced
• unbalanced

Multiple Choice

How many atoms of aluminum are on each side of the following equation: 4Al + 3O₂ --> 2Al₂ O₃

• 2
• 6
• 1
• 4

Multiple Choice

How many atoms of aluminum are on each side of the following equation: 4Al + 3O₂ --> 2Al₂ O₃

• 2
• 6
• 1
• 4

Multiple Choice

Is this balanced?...

Al + O₂ --> 2Al₂O₃

• Yes!

• NO!

Multiple Choice

Is this balanced?...

Al + O₂ --> 2Al₂O₃

• Yes!

• NO!