Chemical Reactions
Vocabulary
Balancing Chemical Equations
How to Balance Equations
Counting Atoms
100

What is the Reactant of the chemical equation and where is it located?

The reactant starting substances and it is always located on the left side of the equation.

100

By definition, the Law of Conservation of Mass states that matter (mass) may not be __________ nor _________ .

created / destroyed.

100

Balance the following equation: _____H2 + ____O2 ---> ____H2O

2 H2 + O2 ---> 2H2O

100

What is the FIRST step to balancing chemical equations?

Count the number of atoms given

100

How many atoms total? 

H2CO3

6

200

What is the Product of a chemical equation and where is it located?

The product is the chemical change or new/ending substance. It is always located on the right side of the equation.

200

This is the force that holds atoms in a compound together. 

CHEMICAL BOND

200

Balance the following Equation: _____KClO3 ---> 2 KCl + ______O2

2KClO3 ---> 2KCl + 3O2

200
Which part of the chemical equation are you to add or change.
The Coefficients
200

How many atoms total? 

(NH4)2S

11

300

Identify the reactants and products in the following chemical equation: H2 + NaCl ---> H2Na + Cl + S

Reactants: HNaCl Products: H2Na, Cl, S

300

12 grams of reactant X react with 15 grams of reactant Y. What is the total mass of the products? 

27 grams

300

Balance the following equation: ____C3H8 + _____O2 ---> ____CO2 + ____H2O

C3H8 + 5O2 ---> 3CO2 + 4H2O

300
Within a chemical formula, if you don't see a subscript, you can conclude that there are how many atoms of that element within each molecule.
One
300

How many atoms total? 

3 Mg(OH)2

15

400

What does it mean for chemical equations to follow the law of conservation of mass? 

For balancing it means the number of atoms of each element must be equal before and after the reaction. 

400

What are broken and formed in chemical reactions? 

Chemical bonds


400

Balance the following equation: ____P + _____O2 --->_____P2O5

4P + 5O2 ---> 2P2O5

400

Which part of chemical equations can we NOT CHANGE? 

The subscripts

400
How many Hydrogen atoms are there?

4 H2O2?

8

500

How many atoms does each element have in the following chemical equation: 2 NaOH + 1 H2CO3 ---> 1 Na2CO3 + 2 H2

2 Na, 5O, 4 H, 1 C

500

BONUS Question ~ DOUBLE Points

How could you speed up chemical reactions?

Higher temperature, higher concentration of reactants, or increased surface area.

500

Balance the following equation: ___NaBr + ____CaF2 ---> ____NaF + ____CaBr2

2NaBr + CaF2 ---> 2NaF + CaBr2

500

Why do we need to balance chemical equations?

To ensure the Law of Conservation of Mass is followed. 

500

How many Hydrogen atoms in a single Ammonia molecule, 3 NH3?

3 Hydrogen