Balancing Equations

What is a coefficient?

• The small number on the right of the chemical symbol.
• The large number to the left of a formula.

Which side of a chemical equation is the product side?

• Left (before the arrow)
• Right (after the arrow)

Which side of a chemical equation is the reactant side?

• Left (before the arrow)
• Right (after the arrow)

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

• Yes
• No

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

• Coefficient 
• Subscript
• Atom
• Equation

Balance this equation.
_Mg + _Cl₂ --> _MgCl₂

• 1, 2,1
• already balanced
• 2,1,1
• 1,1,2

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. 

Is this balanced?...
Fe + S --> FeS

• YES!
• NO!

 Mg  +  ___ HCl  →   MgCl₂  +   H₂

• 1
• 2
• 3
• 4

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

• Yes
• No