WorksheetsBALANCING CHEM EQUATIONS
Total questions: 36
Worksheet time: 56mins
What does the Law of Conservation of Mass say? It says,
"During a chemical reaction, mass is neither _______ or destroyed."
burned
created
melted
The substances that go into a reaction are called the _______.
products
reactants
So, the Law of Conservation of Mass would tell us that the mass of all the REACTANTS must __________ the mass of all PRODUCTS in a chemical reaction.
equal
be greater than
be less than
An ENDOTHERMIC reaction would feel ______ to the touch, while an EXOTHERMIC reaction would feel ______ to the touch.
hot ; cold
cold ; hot
How many HCl molecules do you need to balance this equation?
2Mg + (a) HCl ---> 2MgCl2 + 2H2
What coefficient should be used to make the following equation balanced?
N2+O2--> __?__NO
1
2
3
4
Drag and drop the coefficients that balance this equation 2 Fe + (a) Cl2 ----> (b) FeCl3
Balance this equation (a) N2 + (b) H2 --> (c) NH3
Balance this equation. _CF4 + _Br2 → _CBr4 + _F2
3,1,2,1
1,2,1,2
2,2,2,2
In 3P2O5, there are (a) phosphorus (P) atoms and (b) oxygen (O) atoms.
What's unbalanced about this equation?
Al + O2 --> Al2O3
Oxygen (O) only
Aluminum (Al) only
Both oxygen and aluminum
Nothing; it is balanced.
Balance this equation:
(a) Fe + (b) O2 --> (c) Fe2O3
Mg + __HCl ---> MgCl2 + H2
4Fe + 3O2 --> 2Fe2O3
Al + O2 → 2Al2O3
2H2 + O2 --> 2H2O
Reactants
Products
Subscripts
Coefficients
2H2 + O2 --> 2H2O
Reactants
Products
Subscripts
Coefficients
Atom or molecule?
H2O
Atom
Molecule
Atom or molecule?
Cl
Atom
Molecule
H2 + O2 -> H2O
Coefficient
Product
Subscript
Reactants
What does the part in red tell you?
H2 + O2 -> H2O
How many of that MOLECULE
How many ATOMS of that element
The reactants
The products
What is the number before a molecule or atom called?
Ex: 2H2 + O2 --> 2H2O
Coefficient
Reactant
Subscript
Product
How many atoms of hydrogen (H) are in C6H12O6?
3
6
12
24
How many atoms of hydrogen are in 4NH3?
When balancing equations, what is the ONLY thing you can change?
Molecular structure
Coefficients
Subscripts
Products
Which side has more oxygen (O) atoms: H2O2 --> H2O + O2
Products
Reactants
What's unbalanced about this equation?
Al + O2 --> Al2O3
Oxygen (O) only
Aluminum (Al) only
Both oxygen and aluminum
Nothing; it is balanced.
What is wrong with how this student balanced the equation?
Original equation: Ag + O2 ---> Ag2O
Solution: Ag + O2 ---> 2Ag2O
They changed the molecular structure of the products/reactants.
The silver (Ag) still isn't balanced.
The oxygen (O) still isn't balanced.
They left out the reactants.
What is wrong with how this student balanced the equation?
Original equation: H2 + O2 ---> H2O
Solution: H4 + O2 ---> 2H2O
They changed the molecular structure of the products/reactants.
The hydrogen (H) still isn't balanced.
The oxygen (O) still isn't balanced.
They left out the reactants.
Balance this equation:
(a) Fe + (b) O2 --> (c) Fe2O3
Balance this equation:
(a) FeCl2 + (b) Cl2 --> (c) FeCl3
What is the Law of Conservation of Mass?
It states that matter cannot be created or destroyed.
It states that energy cannot be created or destroyed.
It states that matter can be created or destroyed.
It states that sound can be created or destroyed.
N2+O2--> _NO
H2O
NaHCO3 --> Na2CO3 + H2O + CO2
2CH3OH + 3O2 --> 2CO2 + 4H2O
