Description of Interactive

You will balance three chemical equations by adding elements or molecules to each side of a chemical equation until there are equal numbers on both sides.

1. The formation of water.

Determine the number of hydrogen (H2), oxygen  (O2)  and water (H2O) molecules needed to balance the chemical equation H2 + O2 → H2O

Reactants
Hydrogen (H2)
Oxygen  (O2)

Produces

Products
Water (H2O)

_______H2 + _______O2 → ________ H2O


Answer

2H2 + O2 → 2H2O

When the equation is balanced, you will notice that you have an equal number of hydrogen and oxygen atoms on each side of the equation. 

 

2. The oxidation of copper (what makes copper roofs turn green over time).

Determine the number of copper (Cu), oxygen  (O2)  and copper oxide (CuO) molecules are needed to balance the chemical equation Cu + O2 → CuO

Reactants
Copper (Cu)
Oxygen  (O2)

Produces

Products
Copper oxide (CuO)

______Cu + _______O2 → ________ CuO


Answer

2Cu + O2 → 2CuO

When the equation is balanced, you will notice that you have an equal number of copper and oxygen atoms on each side of the equation. 

 

3. The formation of ammonia (used in fertilizer, and cleaning products).

Determine the number of nitrogen (N2), hydrogen (H2),  and ammonia (NH3) molecules needed to balance the chemical equation N2 + H2 → NH3

Reactants
Nitrogen (N2)
Hydrogen (H2)


Produces

Products
Ammonia (NH3)

_______N2 + _______H2 → ________ NH3


Answer

N2 + 3H2 → 2NH3

When the equation is balanced, you will notice that you have an equal number of nitrogen and hydrogen atoms on each side of the equation. 

 

4.  The formation of magnesium oxide. Determine the number of magnesium (Mg), oxygen (O2) and magnesium oxide (MgO) molecules needed to balance the chemical equation.

Reactants
Magnesium (Mg)

Oxygen (O2)


Produces

Products

Magnesium Oxide (MgO)

_______Mg + _______O2 → ________ MgO


Answer

2Mg + O2 -> 2MgO

Magnesium metal when burned in the presence of oxygen gas, produces magnesium oxide.

5. Replacement reaction of potassium iodide and chlorine gas. Determine the number of potassium (K), chlorine (Cl2), potassium chloride (KCl) and iodine (I2) molecules needed to balance the chemical equation. 

Reactants
Potassium (K)

Chlorine (CI2)


Produces

Products

Potassium Chloride (KCI)

Iodine (I2)

_______KI + _______CI2 → ________ KCI + _______I2


Answer


2KI + Cl2 -> 2KCl + I2

Potassium iodide mixed with chlorine gas produces potassium chloride and iodine gas.