Counting Atoms and Balancing Equations

How to Balance Chemical Equations

Multiple Choice

What is the Law of Conservation of Mass?

• It states that matter cannot be created or destroyed.

• It states that energy cannot be created or destroyed.

• It states that matter can be created or destroyed.

• It states that sound can be created or destroyed.

Multiple Choice

What is a coefficient?

• The small number on the right of the chemical symbol.

• The large number in front of a chemical formula.

• The number in between the chemical symbols.

• The number behind a chemical formula.

Multiple Choice

What is the part of the chemical equation in green called?

Fe + S --> FeS

• products

• reactants

• yield

• chemical formula

Multiple Choice

What is the little number after an element in a chemical equation called.

Example: H₂

• Coefficient

• Subscript

• Atom

• Equation

Multiple Choice

What coefficient should be used to make the following equation balanced?
N₂+O₂--> _NO 

• 1
• 2
• 3
• 4

Multiple Choice

Which problem is balanced?
(Check ALL answers)

• PbO₂ + 2H₂
• SO₂ + H₂0 --> H₂SO₄
• 2Na + 2H₂O --> 2NaOH + H₂

Multiple Choice

How many HCl molecules do you need to balance this equation? 
Mg +  __HCl --->  MgCl₂ + H₂

• 1
• 2
• 3
• 4

Multiple Choice

What is the right part of a chemical equation called...
2H_{2 +} O₂ --> 2H₂O

• Reactants
• Products 
• Yields 
• Chemical Equation 

Multiple Choice

What does the Law of Conservation of Mass state?

• Matter cannot be gained or lost in a chemical reaction.
• Matter can only be lost in a chemical reaction.
• Matter can only be gained in a chemical reaction.
• Matter can be gained and lost in a chemical reaction. 

Multiple Choice

Balance this equation.

_SnO₂ +_H₂-->_Sn +_H₂O

• 1,1,2,1

• 1,2,1,1

• 1,2,1,2

• 1,2,2,1

Multiple Choice

Balance this equation

_Al +_HCl --> _H₂ +_AlCl₃

• 2, 6, 3, 2

• it is already balanced

• 4, 12, 3, 4

• 2, 1, 4, 5

Multiple Choice

Balance this equation.

_CH₄ + _O₂ --> _CO₂ + _H₂O

• 1,2,1,1

• 2,1,2,1

• 1,2,1,2

• 0,2,0,2

Multiple Choice

Is this balanced?
Al + O₂ → 2Al₂O₃

• Yes
• No

Multiple Choice

2NH₃ + 3CuO --> N₂ + ___Cu + 3H₂O

• 1

• 2

• 3

• 4

Multiple Choice

2H₂ + O₂ --> ___H₂O

• 1

• 2

• 3

• 4

Multiple Choice

2NaN₃ --> 2Na + ___N₂

• 1

• 2

• 3

• 4

Multiple Choice

2KClO₃ --> ___KCl + 3O₂

• 1

• 2

• 3

• 4

Multiple Choice

C₂H₅OH + ___O₂ --> 2CO₂ + 3H₂O

• 1

• 2

• 3

• 4

Multiple Choice

3Pb(NO₃)₂ + 2Na₃PO₄ --> ___Pb₃(PO₄)₂ + 6NaNO₃

• 1

• 2

• 3

• 4

Multiple Choice

___Pb + S --> PbS + Pb

• 1

• 2

• 3

• 4

Multiple Choice

2Al + ___Cl₂ --> 2AlCl₃

• 1

• 2

• 3

• 4

Multiple Choice

___AlBr₃ + 3Cl₂ --> 2AlCl₃ + 3Br₂

• 1

• 2

• 3

• 4

Multiple Choice

4Ag + O₂ --> ___Ag₂O

• 1

• 2

• 3

• 4

Multiple Choice

2NaCl + CaO --> ___Na₂O + CaCl₂

• 1

• 2

• 3

• 4

Multiple Choice

CO + ___H₂ --> CH₄ + H₂O

• 1

• 2

• 3

• 4

Multiple Choice

Balance this equation

_Al +_HCl --> _H₂ +_AlCl₃

• 2,6,3,2

• it's already balanced

• 4,12,3,4

• 2,1,4,5