Chemical Reactions. Chemical Reaction: The conversion of old material into new material via a chemical change. The Basic form for all chemical equations is: Old Stuff New Stuff Read the above line like this: “The old stuff reacts to form the new stuff.”
Chemical Reaction: The conversion of old material into new material via a chemical change.
The Basic form for all chemical equations is: Old Stuff New Stuff
Read the above line like this:
“The old stuff reacts to form the new stuff.”
“The old stuff yields the new stuff.”
“The new stuff is produced from the old stuff.”
Old Stuff = reactants
(cuz they’re what’s reacting)
New Stuff = products
(cuz they’re what’s being produced)
Ex: Hydrogen peroxide reacts to form water and oxygen.
Convert names to formulas & write equation.
Hydrogen peroxide = H2O2
Water = H2O
Oxygen = O2
Chemical Equation = H2O2 H2O + O2
Four abbreviations are used to indicate physical states of chemicals:also shown as part of the chemical equation
(s) = solid
(l) = liquid
(g) = gas
(aq) = aqueous solution(=dissolved in water)
There is no way that you can predict the physical states of materials. This is only done through observation.
There is no pattern to the physical states in a reaction. A solid can give a solid, liquid, gas, or aqueous material.
*This is why we cannot predict the physical states of materials.
What are the driving forces that drive reactants toward products?
1. Formation of a solid (Precipitate)
2. Formation of water (Acid/Base rxns)
3. Transfer of electrons (oxidation/reduction rxns)
4. Formation of a gas (combustion)
There are four (5) types of chemical reactions.
You can count them on one hand!
3. Single Replacement
1. Combination or
4. Double Replacement
Here we have it in
of our hand
Two or more reactants form one product
A + B AB
2Na(s) + Cl2 2NaCl
One reactant forms two or more products
AB A + B
2H202 2H20(l) + O2(g)
An element reacts with a compound to form a new element and a new compound.
AB + C AC + B
The “C” replaced the “B”
2Na(s) + 2H20 2 NaOH(aq) + H2
Two Compounds react and produce 2 new compounds.
AB + CD AD+ CB
FeS(s) + 2HCl(aq) H2S(g) + FeCl2(aq)
A material reacts with oxygen to form a variety of compounds.
AB + O2 misc. products
4Al(s) + 3O2(g) 2Al2O3
C3H8(g) + 5O2(g) 3CO2(g) + 4H20(g)
You have to be able to recognize the type of reaction and what should result.
Look at the table on p.197 for general patterns.
Do the rest of the practice problems on p. 198.