Chemical Equations and Balancing

How many Hydrogen are in 4H₂O?

• 6
• 8
• 2
• 4

Which of the following shows the correct way to balance the chemical equation?
Fe + O₂ -> Fe₂O₃

• 4Fe + 3O₂ -> 2Fe₂O₃
• 2 Fe + 3O₂ -> Fe₂O₆
• 4 Fe + O₆ -> 2Fe₂O₃
• None of the options are correctly balanced.

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. 

Balance this equation-
__P₄ + __O₂ --> __P₂O₃

• it is already balanced
• 2, 1, 3
• 1, 2, 3
• 1, 3, 2

What is the arrow in a chemical equation...

H_{2 +} O₂ --> H₂O

• Reactants

• Products

• Yields

• Chemical Equation

To balance an equation you should:

• ONLY change subscripts.

• ONLY change coefficients.

• Change BOTH subscripts and coefficients.

If an element is diatomic it should have a subscript of___

• 1, always

• 2, only when it is an element

• it shouldn't have a subscript, it should have a coefficent

• 2, when bonded in a compound

The symbol for a substance dissolved in solution is ______

• (s)

• (l)

• (aq)

• (g)

Fill in the blank. (Copper has a charge of 2+)

Cu+ AgNO₃ → Ag + _____

• Cu(NO₃)₂

• CuNO₃

• CuAg

• Cu

_AlBr₃ + _K₂SO₄ → _KBr + _Al₂(SO₄)₃

• 6 AlBr₃ + 1 K₂SO₄ → 6 KBr + 1 Al₂(SO₄)₃
• 2 AlBr₃ + 3 K₂SO₄ → 6 KBr + 1 Al₂(SO₄)₃
• 1 AlBr₃ + 1 K₂SO₄ → 2 KBr + 3 Al₂(SO₄)₃
• 2 AlBr₃ + 3 K₂SO₄ → 1 KBr + 2 Al₂(SO₄)₃