Balancing equations

The Law of Conservation of Matter

• tells how many atoms of an element are contained in one molecule or formula unit.

• the starting materials in a chemical reaction

• the new substances that are formed in a chemical reaction

• A law stating that atoms are not created or destroyed during a chemical reaction.

Is the equation balanced?: 2H₂O + O₂ --> 4MgO + 3Fe

• yes

• no

Balance this equation

_Al +_HCl --> _H₂ +_AlCl₃

• 2,6,3,2

• it's already balanced

• 4,12,3,4

• 2,1,4,5

The coefficient in 3H₂O is

• 6

• 5

• 2

• 3

How many atoms of carbon (C) are in C₆H₁₂O₆?

• 3
• 6
• 12
• 24

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 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!

What is the number before a chemical formula called?
Ex: 2H₂ + O₂ --> 2H₂O

• Coefficient
• Subscript
• Atom
• Equation