Chemical Reactions
Definition of a chemical reaction?
Reaction where a new substance is formed.
Reaction where no new substance is formed.
Compounds in a reaction on the left side of the arrow are the ________, on the right side of the arrow they are called the ________.
Reactants, products.
Basic principle for making sure that chemical equations and number of atoms are balanced?
Law of Conservation of Matter
HI (g) --> H2 (g) + I2 (g)
2 HI (g) --> H2 (g) + I2 (g)
What is a sign that a chemical reaction has occurred?
Gas, light, temp, new substance, colour
What is a sign that a physical change has occured?
State or shape change
Two types of equations?
Word & Chemical/Symbol Equations
Fe2O3 + Al → Fe + Al2O3
Fe2O3+2Al→2Fe+Al2O3
FeO (s) + O2 (g) --> Fe2O3 (s)
4 FeO (s) + O2 (g)g --> 2 Fe2O3 (s)
List 3 examples of chemical reactions?
Various answers
3 examples of physical reactions?
Various answers.
s, l, g, aq
CH4+O2→CO2+H2O
CH4+2O2→CO2+2H2O
Li + AuCl3 --> LiCl + Au
3 Li + AuCl3 --> 3 LiCl + Au
What are the new substances formed by a chemical reaction called?
Products
Process water goes through during three types of physical change?
Solid ice, melts to liquid water, evaporates to water vapour gas
Symbol equation for the following worded equation?
carbon monoxide + water -> carbon dioxide + hydrogen
CO + H2O -> CO2 + H2
C2H5OH+O2→CO2+H2O
C2H5OH+3O2→2CO2+3H2O
C10H8 + O2 --> CO2 + H2O
C10H8 + 12 O2 --> 10 CO2 + 4 H2O
Rust is a chemical compound called iron oxide. It forms very slowly as iron reacts with oxygen and water.
What are the reactants?
Iron, oxygen, water
List all 4 states of matter?
solid, liquid, gas, aqueous.
Two major things that symbol equations provide that word equations don't?
Number of atoms & states of matter
H2SO4+NaOH→Na2SO4+H2O
H2SO4+2NaOH→Na2SO4+2H2O
NiCl2 + O2 --> NiO + Cl2O5
NiCl2 + 3 O2 --> NiO + Cl2O5