Chemical Reactions
Where are reactants located in a chemical equation?
What is the FIRST step to balancing chemical equations?
Make chart or List/count the elements
Balance the following equation: _____H2 + ____O2 ---> ____H2O
2 H2 + 1 O2 ---> 2 H2O
Balance the following chemical equation:
___ C + ___ S8 ---> ___ CS2
4 C + 1 S8 ---> 4CS2
What type of reaction is:
2 H2 + 1 O2 ---> 2 H2O
Synthesis
Where are the products located in a chemical equation?
On the right.
Which part of a chemical equation can you change to balance?
Coefficients
Balance the following Equation: _____KClO3 ---> KCl + ______O2
2 KClO3 ---> 2 KCl + 3 O2
Balance the chemical equation:
__ Li + __ H2O ---> ___ LiOH + ___ H2
2 Li + 2 H2O ---> 2 LiOH + 1 H2
What type of reaction is:
NH3 + I2 ---->N2I6 + H2
Single replacement
What is the difference between a coefficient and a subscript?
Coefficients = how many molecules we have, subscripts = how many atoms we have in a molecule
If you don't add a coefficient in front of a molecule, you have _______ of that molecule.
One
Balancing chemical equations:
____ N2 + ____ H2 ----> ____ NH3
1 N2 + 3 H2 --> 2 NH3
What type of reaction is:
H2SO4 + NH4OH ----> H4O + (NH4)2SO4
Double replacement
What does the law of conservation of mass state?
The law of conservation of mass states that matter durning a chemical change can neither be created nor destroyed.
Which molecule should you balance LAST in this equation? O2 + CH4 --> CO2 + H2O
Oxygen, because it is alone and won't affect other elements when you change the coefficient of O2.
Balance the following equation: ____P + _____O2 --->_____P2O5
4 P + 5 O2 ---> 2 P2O5
Balance the following chemical equation: ___ N2 + ___ O2 ----> ___ N2O5
2 N2 + 5 O2 ----> 2 N2O5
What type of reaction is an acid/base neutralization, like one seen in the following reaction.
H2SO4 + 2NaOH ---> Na2SO4 + 2H2O
Double replacement
Identify the NAMES of the reactants and products in the following chemical equation: H2SO4 + 2NaOH ---> Na2SO4 + 2H2O
Reactants: Hydrogen Sulfate (sulfuric acid) and sodium hydroxide
Products: sodium sulfate and dihydrogen Monoxide (water)
Why do we balance chemical equations?
Because of the Law of Conservation of Mass.
Balance the following equation: ____C3H8 + _____O2 ---> ____CO2 + ____H2O
1 C3H8 + 5 O2 ---> 3 CO2 + 4 H2O
Balance the following chemical equation:
____ C2H6 + ___ O2 ---> ____ CO2 + ____ H2O
2 C2H6 + 7 O2 ---> 4 CO2 + 6 H2O
This reaction occurs in cars to make them move, using gasoline (a hydrocarbon) and oxygen gas as reactants.