GRADE 8 - BALANCING EQUATIONS

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. 

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

• Reactants
• Products 
• Yields 
• Chemical Equation 

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

• Reactants
• Products 
• Yields 
• Chemical Equation 

What is the total number of atoms present in 5Na₃PO₄

• 5
• 40
• 55
• 8

What is the little number after an element in a chemical equation called.
Example: H₂

• Coefficient 
• Subscript
• Atom
• Equation

Is the following equation balanced?...
Al + O₂ --> 2Al₂O₃

• Yes!
• No!

Is the following equation balanced?
2C₂H₂ + 5O₂ --> 4CO₂ + 2H₂O

• yes
• no

Which of the following equations are correctly balanced?

• 12CO₂ +H₂O --> C₆H₁₂O₆ + O₂
• CO₂ + 9H₂O --> C₆H₁₂O₆ + O₂
• CO₂ + H₂O --> 3C₆H₁₂O₆ + O₂
• 6CO₂ + 6H₂O --> C₆H₁₂O₆ + 6O₂

Is the following reaction balanced?
NaHCO₃ --> Na₂CO₃ + H₂O + CO₂

• yes
• no

Balance the following equation:

___ H₂+ ___ O₂→___ H₂O

• 1, 1, 3

• 2, 2, 2

• 1, 2, 1

• 2,1, 2