Electrolytes
- Ionic compounds are strong electrolytes (single arrow for dissociation reaction)
- Most molecule compounds (not molecular acids) are nonelectrolytes
- Strong molecular acids are strong electrolytes (single arrow)
- Weak bases are weak electrolytes (doub
Solubility rules
- All compounds containing alkali metal cations and ammonium ion are soluble
- All compounds containing NO3-, ClO4-, ClO3-, and C2H3O2- anions are soluble.
- All chlorides, bromides, and iodides are soluble except those containing Ag+, Pb2+, or Hg2+
- All
Metathesis Reactions
- Use formulas to determine ions present.
- Write formulas of product by switching cations and anions (use charge to find new formulas)
- Balance
Types of Equations
Molecular equation - shows the
complete chemical formulas of reactants
and products
Complete ionic equation - shows all
soluble strong electrolytes as ions (split
the aqueous compounds)
Net ionic equation - shows reaction
after spectator ions are eliminat
Writing net ionic equations
(i) Write balanced molecular equation.
(ii) Separate all aqueous strong
electrolytes into ions.
(iii) Cancel spectator ions.
Common Precipitates
Hydroxides, carbonates, phosphates, and
chromates (except with ammonium and
group 1)
Acids
contain ionizable hydrogen
(proton donor).
Acid formulas usually start with a
hydrogen or contain -COOH.
Acids have a sour taste and burn.
Monoprotic - 1 ionizable hydrogen
o HCl
o CH3COOH, the hydrogen in the
carboxyl group (COOH) is ionizable
Diprotic -
Bases
Bases - accept ionizable hydrogen
(proton acceptor).
Bases taste bitter and feel slippery.
Bases often contain hydroxide or
amines (-NH2).
Other aqueous anions can also attract
protons to form insoluble compounds or
gases and function as bases.
Ammonia (N
Seven strong acids
Hydrochloric acid, HCl
Hydrobromic acid, HBr
Hydroiodic acid, HI
Chloric acid, HClO3
Perchloric acid, HClO4
Nitric acid, HNO3
Sulfuric acid, H2SO4
Eight strong bases
Group1 hydroxides
o LiOH, NaOH, KOH, RbOH, CsOH
Heavy group 2 hydroxides
o Ca(OH)2, Sr(OH)2, Ba(OH)2
Neutralization reactions
- When acidic and basic hydroxide solutions mix the
result is water and a salt (ionic compound
formed from a cation from an base and
an anion from an acid)
Gas forming acid-base reactions
carbonates (and hydrogen carbonates)
H2O and CO2 + salt
Sulfites (SO3) H2O and SO2 + salt
Sulfides H2S + salt
Nitrites (NO2) NO + NO2 + salt
Oxidation-reduction reactions
Leo Ger OIL RIG
Oxidation: loss of e
; ox # increases
Reduction: gain of e
; ox # decreases
example: Fe
2+
+ 2e
Fe(s) (reduction)
Oxidation number rules
Elements in their elemental form have
an oxidation number of 0.
The oxidation number of a monatomic
ion is the same as its charge.
Oxygen has an oxidation number of -2,
except in the peroxide ion (O2
2-
) in
which it has an oxidation number of -1.
Hydroge
Half reaction method
determine oxidation & reduction
write two separate half-reactions
balance all atoms except H & O
balance O's (add H2O's)
balance H's (add H+'s)
add e
's to more positive side
balance e's between half-reactions
combine half-reactions
Molarity
Molarity (M) = moles of solute / liters of solution
Dilution
M1V1=M2V2
Solution Stoichiometry
- Moles (mole ratio) are the common link that connect
all substances in chemical reactions.
How do you get from substance A to
substance B?
o Mole ratio from the coefficients in
the balanced equation
How do you get to (and from) moles?
o Liters - use mola
TItration
- analytical technique used to determine the unknown concentration of a solution by reacting it with a solution of
known concentration (called a standard solution).
Can be an acid-base neutralization, redox, or any other type of reaction.
Equivalence poin