Physical/Chemical Changes
Chemical Equations
Counting Atoms
Law of Conservation of Mass
Miscellaneous
100
Breaking an egg and freezing a popsicle are what type of changes?
physical change
100
These are found on the left side of a chemical equation
What is the reactants?
100
4Na3OS
How many sodium atoms are present?
12 atoms
100
How can you tell if an equation is balanced?
The number of atoms of each element on the reactants is equal to the product
100
Substances with a pH less than 7 are called?
Acids
200
What type of change causes a change in state or phase of matter from a solid to a liquid?
a physical change
200
These are found on the right side of a chemical equation
What is the product?
200
2C4H10O has how many total atoms
What is 30?
200
How does the mass of the reactants compare to the mass of the product?
They are both equal.
200
What does the presence of a new substance usually mean?
a chemical change took place
300
What kind of change occurs when water evaporates from salt water?
What is a physical change?
300
2C4H10O
What is the number of molecules?
2 (coefficient)
300
6CO2 + 6H2O → C6H12O6 + 6O2 has how many oxygen in the reactants
What is 18?
300
Does this follow the law?
2H2O2 --> 2H2O + O2
Yes
300
When the atoms in a reactants are rearranged in the product what does it mean?
The Law of Conservation of Mass occurred or it is balanced
400
What type of reaction causes a gas to form?
a chemical change
400
2Na3AsO3
How many elements are present?
3
400
2Fe + 3HC2H3O2 → 2Fe(C2H3O2)3+ 3H2
How many atoms in the product?
50
400
SnO2 + 2H2 → Sn + 2H2O
_?__ + 16g → 29g + 32g
45g
400
2 g of O2
500
Leaves using CO2 to make sugar and
fungus decomposing organic matter
chemical change
500
H2 + O2 → CH2O
16.0 + 2.02 → ?
18.02 g
500
Cu + 2AgNO3→ Cu(NO3)2 + 3Ag
How many atoms in the chemical reaction?
23 atoms
500
State the Law of Conservation of Mass
What is Energy is not created or destroyed it just changes form?
500
Element 2