Unit 4: Chemical Reactions

Strong Electrolytes

Strong Electrolytes

substances that completely ionize or dissociate in water.

Types of Strong Electrolytes

S.A.S.: strong acids, aqueous ionic compounds, strong bases

The Six Strong Acids

HCL (hydrochloric acid)
HBr (hydrobromic acid)
HI (hydroiodic acid)
HNO3 (nitric acid)
H2SO4 (sulfuric acid)
HClO4 (perchloric acid)

HCl (g) + H2O (l) → ???

HCl (g) + H2O (l) → H3O+ (aq) + Cl-

NaCl (s) → (when dissolved in H2O)

NaCl (s) → Na+ + Cl-

Types of Strong Bases

alkali metals, barium, or strontium bonded to the hydroxide ion
(Li, Na, K, Rb, Cs, Fr, Ba, Sr)

Ba(OH)2 (s) → (when dissolved in H2O)

Ba(OH)2 (s) → Ba+2 (aq) + 2OH- (aq)

Weak Electrolytes

substances that only ionize a little bit in water (<5%); uses a double sided arrow when showing reactions

Types of Weak Acids

any acids that are not part of the six strong acids

HC2H3O2 (aq) ⇌ ??? (when dissolved in water)

HC2H3O2 (aq) ⇌ H+ (aq) + C2H3O2- (aq)

Types of Weak Bases

ammonia or ammonia-like compounds (amines) (has an N with a lone pair attached to it)

NH3 + H2O → ???

NH3 + H2O → NH4+ + OH-

Non Electrolytes

substances that dissolve but do not break into ions

Types of Non Electrolytes

non-acidic/basic covalent compounds like sugars (CxHxOx) and alcohols (CxHyOH) and insoluable ionic compounds

C12H22O11 (s) → ??? (when dissolved in water)

C12H22O11 (s) → C12H22O11 (aq)

The ________ the ion concentration, the __________ the conductor.

The greater the ion concentration, the better the conductor.

S.N.A.P. Rule

all sodium (Na+), nitrate (NO3-), ammonium (NH4+), and potassium (K+) salts are aqueous in water

Solubility Rule #1: All __________ and __________ salts are aqueous.

All alkali metal and ammonium salts are aqueous.

Solubility Rule #2: All ________, ________, ________, and ________ are aqueous.

All nitrates, acetates, perchlorates, and chlorates are aqueous.

Solubility Rule #3: All ________, ________, and ________ are aqueous unless bonded to ________, ________, or ________.

All chlorides, bromides, and iodides are aqueous unless bonded to lead (Pb+2), mercury (Hg2+2), or silver (Ag+) (PMS).

Solubility Rule #4: All ________ are aqueous unless bonded to _____, _____, _____, and PMS.

All sulfates are aqueous unless bonded to Ca2+, Ba2+, Sr2+, and PMS. (CBS and PMS)

Solubility Rule #5: All ________, ________, ________, ________, ________, and ________ are precipitates unless bonded to rule #1.

All carbonates, sulfides, oxides, hydroxides, phosphates, and chromates are precipitates unless bonded to rule #1. (SHOP CC)

Solubility Rule #6: All ________, ________, and ________ salts are precipitates unless bonded to rule #1.

All silver, lead, and mercury(I) salts are precipitates unless bonded to rule #1.

Steps to a Net-Ionic Equation Problem

1. Write out balanced molecular equation with states of matter

2. Rewrite balanced equation splitting up any strong electrolytes

3. Cross out any spectator ions

4. Box your final answer

If a burning splint test results in a popping noise, what gas is being produced?

H2

If a burning splint test results in it being extinguished, what gas is being produced?

CO2

If a glowing splint test results in it being reignited, what gas is being produced?

O2

Reduction-Oxidation reactions involve __________ and are identified by a change in __________.

Reduction-Oxidation reactions involve transfer electrons and are identified by a change in oxidation numbers.

Oxidation Number

the charge an atom would have in a molecule/compound if electrons were transferred completely

Oxidation Number Rule: Fluorine is always a ___ in compounds.

-1

Oxidation Number Rule: Oxygen is usually a ___ in compounds (unless it’s peroxide, where each oxygen is ___).

-2, -1

Oxidation Number Rule: Hydrogen is ___ in covalent compounds and ___ when bonded to metals.

+1, -1

Order of Electronegativity for HONClBrIF

F, O, N, Cl, Br, C, H

Oxidation

process of losing electrons

Reduction

process of gaining electrons (oxidation number reduces)

Oxidizing Agent

whichever species is being reduced; whichever ion/molecule is gaining electrons, allowing for something else to be oxidized

Reducing Agent

whichever species is being oxidized; whichever ion/molecule is losing electrons, allowing something else to be reduced

Steps to a Redox Reaction

1. Write the balanced net ionic equation

2. Split the net ionic equation into two half reactions

3. Add electrons to balance out the charges in each half reaction (should be on opposite sides for each half reaction)

4. Put the two half reactions together

5. Cancel out the electrons

Acid-Base Reaction

involves the transfer of one or more protons (H+) between chemical species.

Types of Acid-Base Reactions

Acid + Base → Salt + H-OH
Acid + Metal Carbonate → Salt + H2O + CO2
Bronsted-Lowry Acid-Base Reactions

Bronsted Acid

species in a bronsted-lowry reaction that donates a proton/H+(always has a conjugate base on the product side)

Bronsted Base

species in a bronsted-lowry reaction that accepts a proton/H+ (always has a conjugate acid on the product side)

Precipitation Reactions

when two aqueous solutions combine to make an insoluble salt precipitate