Chemical Reactions
Where are reactants located in a chemical equation?
Which part of a chemical equation can you change to balance?
Coefficients
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
Can a chemical equation only have one molecule as a reactant?
Yes
Identify the reactants and products in the following chemical equation: H2 + NaCl ---> H2Na + Cl2 + S
Reactants: H, Na, Cl Products: H, Na, Cl, S
If you don't add a coefficient in front of a molecule, you have _______ of that molecule.
One
Balance the following Equation: _____KClO3 ---> _____KCl + ______O2
2KClO3 ---> 2KCl + 3O2
Balance the chemical equation:
__ Li + __ H2O ---> ___ LiOH + ___ H2
2 Li + 2 H2O ---> 2 LiOH + 1 H2
Define what it means to have a "balanced chemical equation"
Equal amounts of atoms on both sides
What is true of all of the following: H2 O2 Cl2 N2
They are all gases at room temperature.
Which molecule should you balance LAST in this equation? O2 + CH4 --> CO2 + H2O
Oxygen, because it is in three different molecules it is likely the most challenging to balance.
Balancing chemical equations:
____ N2 + ____ H2 ----> ____ NH3
1 N2 + 3 H2 --> 2 NH3
What does the arrow from reactants --> products mean?
Produces
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.
If you do not make this all your equations are balanced or they are impossible to balance.
What is neutral chemicals?
Balance the following equation: ____P + _____O2 --->_____P2O5
4P + 5O2 ---> 2P2O5
Balance the following chemical equation: ___ N2 + ___ O2 ----> ___ N2O5
2 N2 + 5 O2 ----> 2 N2O5
List ONE trick in balancing equations that you could use to help you.
Odd/even, single elements last
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
Balance the following equation: ____C3H8 + _____O2 ---> ____CO2 + ____H2O
1C3H8 + 5O2 ---> 3CO2 + 4H2O
Balance the following chemical equation:
____ C2H6 + ___ O2 ---> ____ CO2 + ____ H2O
2 C2H6 + 7 O2 ---> 4 CO2 + 6 H2O
A student completes an experiment to test the law of conservation of mass by reacting baking soda with vinegar. The students mixes the baking soda and vinegar in an open beaker. The mass of the reactants was 100g and the mass of the products was 50g. What did the students do wrong that caused the mass of the products to be less than the mass of the reactants?
Did not put a cover one the beaker, allowed gas to escape.