Test 8- Reactions Flashcards
Chemical reaction
A process by which one or more substances are changed into one or more different substances
Substance
Atom (element), Formula Unit (ionic compound), or molecule (covalent bonded compound)
Atom
Element all by itself
Formula Unit
ionic compounds- metal and nonmetal
Molecule
covalent compound=2 nonmetals
To represent a chemical reaction
use an equation- can be with words or symbols
Reactants yield sign
⇒ products
Plus sign
separates reactants/products
Phases of matter
in parenthesis after substance symbols
- S= Solid
- L= liquid
- G= gas
- Aq= aqueous
Aqueous
dissolved in water- water doesn’t take place in the reaction
Coefficient
(big number in front of the substance symbol)= number of particles in the substance
Subscripts
used to write the formula correctly so that we have a net charge of zero
catalyst
- speeds up the reaction without changing its structure
- represented above the yield sign
up arrow indicates
g, don’t need to put it in parenthesis
Δ=
add heat for reaction to occur
Down arrow indicates
s for a precipitate, don’t put in parenthesis
Endothermic
Energy+reactants⇒products
Exothermic
Reactants⇒Products+Energy
Exothermic
Reactants⇒Products+Energy
Reaction types
- Synthesis or Composition
- Decomposition
- Single Replacement/Single Displacement
- Double Replacement/Double Displacement/Ionic
- Water forming/Neutralization
- Combustion
Synthesis or Composition
- Many reactants⇒one product
- Opposite of synthesis/composition
Types of Synthesis or Composition
2 types:
a) Metals with Halogens (all diatomic)
Ex. Na(s)+Cl2(g)⇒2NaCl(s)
b) With oxides (end in O)
Ex. CaO(s)+H2O(l)⇒Ca(OH)2(s)
Decomposition
One reactant⇒many products
Types of Decomposition
6 Types:
- Electrolysis
- Binary
- Metal carbonate
- Metal hydroxide
- Metal chlorate
- Tertiary acid
First type of decomposition
Electrolysis
- Use electricity to break the bond
- Ex. H2O(l)⇒2H2(g)+O2(g)
Second type of decomposition
Binary
- Take elements in compound and break them apart
- Ex. 2HgO(s)⇒2Hg(l)+O2(g)
Third type of decomposition
Metal Carbonate breaks to form metal oxide+carbondioxide
- Ex. CaCO3(s)⇒(Δ above arrow) CaO(s)+CO2(g)
Fourth type of decomposition
Metal hydroxide to form metal + water
- Ex. Ca(OH)2(s)⇒(Δ above arrow)CaO(s)=+H2O(l)
Fifth type of decomposition
Metal chlorate to form a metal chloride and oxygen
- Ex. 2KClO3(s)⇒2KCl(s)+3O2(g)