Honors Chemistry Semester 1

Density

mass/volume

Volume

mass/density

Mass

Density times volume

Sig Fig Rules

1. Every nonzero digit in a recorded measurement is significant

2. Zeros between nonzero digits are significant (“Sandwich Rule”)

3. Zeros in front of all nonzero digits are NOT significant

4. Zeros at the end of a measurement where there is no decimal point are ambiguous. To clearly show the correct number of sig figs, they should be written in scientific notation.

   EX: 120= 2/3 sig figs; 3000= ¾ sig figs

0.004550

4 sig figs- The zero in front of all nonzero digits are not significant, and zeros at the end of a measurement where there is no decimal point are ambiguous.

number of sig figs for multiplication/division

number of sig figs in the least precise measurement

number of sig figs in addition/subtraction

result has the same number of decimal places as the least precise measurement

Metric System (MEMORIZE!!)

1. Peta; P; 10^15

2. Tera; T; 10^12

3. Giga; G; 10^9

4. Mega; M; 10^6

5. Kilo; K; 10³

6.hecto; h; 10²

7. deka; da; 10^1

8.deci; d; 10⁻¹

9.centi; c; 10⁻²

10.milli; m; 10⁻³

11.micro; ; 10⁻⁶

12.nano; n; 10⁻⁹

13. pico; p; 10⁻¹²

Specific gravity

measure of mass of an object compared to the mass of an equal volume of water

density of water

1.00 g/ml, specific gravity is equal numerically to the density but HAS NO UNITS

Water displacement

D= m/Vfinal - Vinitial

Angstrom

1 Angstrom= 10^-10 m

Accuracy

closeness of a measurement to the actual value

Absolute error

[Observed value- Accepted Value]

Relative error

[observed value-accepted value]/accepted value *100

JJ Berzelius

created modern symbols of elements

Group 1A

Alkali Metals (except Hydrogen)

Group 11A

Alkaline Earth Metals

Group V11A

Halogens

Group V111A

Noble Gases

Physical properties of substances

Density, specific gravity, hardness, odor, color, taste, solubility, physical state, properties of metals, accidental physical properties (mass and volume)

Chemical properties

color, gas, solid, heat/temperature changes

Homogenous

uniform, constant composition

Heterogenous

non-uniform (varying composition)

Democritus

Matter is composed of indivisible particles called atoms

Law of Conversation of Mass-Antoine Lavosier

mass is neither created nor destroyed

Law of Constant Proportions- Joseph Proust 1799

Compounds always contain the same elements in the same proportions by mass

Law of Multiple Proportions- John Dalton

When two elements can form multiple compounds, the ratio of masses will remain constant for each compound

JJ Thompson

used experiments with Cathode Ray Tube to show that atoms are not indivisible and determined e/me= constant; proposed Plum Pudding Model

Robert A Milikan

Determined e- charge with oil drop experiment

Rutherford

Use radioactive a to discover the +charged nucleus with alpha scattering experiment and proposed incorrect planetary model

Incorrect planetary model

Electrons orbit positive nucleus; this model cannot explain why electrons wouldn’t crash into nucleus

Stable atoms

have favorable n(neutrons)/p(protons) ratio

Larger atoms v. Smaller atoms

Larger atoms= n>p; Smaller atoms= n=p

Belt of stability

Above stability band means that there are too many neutrons and must go through beta emission(neutrons turn into protons)

Below stability band means that there are too many protons and they must go through positron emission(protons turn into neutrons)

Picometer

Picometer= 10^-12 m

Mass number(on top)

Number of protons and neutrons

Atomic number(bottom)

Number of protons

Alpha emissions

4 2 He (subtract 4 and 2)

Beta Emission- neutrons turn into protons

0 -1 e (add 1)

Positron emission- protons turn into neutrons

0 1 e (subtract 1)

Gamma Emission

When nucleus is in an excited energy state and it loses energy gamma rays are emitted; no changes during equation

B+ emission

below stability belt

B- emission

Above stability belt

Radioactive Decay Series

successive decays which start with one parent isotope and proceeds through a number of daughter isotopes. The series ends when a stable, non-radioactive isotope is formed.

What nuclei are most stable?

Nuclei with large binding energies per nuclei

Most stable isotope

56 Fe

What nuclei are very stable?

Nuclei of low atomic numbers with a 1:1 ratio of neutrons to protons are very stable

Stable nuclei

even # of protons and neutrons

Conversion between mass and energy formulas

1 g= 6.022 × 10 ^ 23 amu

I Joule= kg*m²/s²

c= 3.00 × 10^8 m/s

E=mc²

Mass Defect, Binding Energy, Stability

As Mass Defect increases, so does binding energy and stability

Half Lives

the average time it takes for half of the unstable atoms in a sample to decay

Fusion

combining smaller nuclei to form larger nuclei, which increases the binding energy per nucleon and therefore the stability

Nuclei smaller than 56 Fe

give off energy when they fuse together

Fission

Large nucleus is broken into smaller nuclei and one or more neutrons; takes place for electrons larger than 56 Fe

Nuclear Chain Reaction

self-sustaining sequence of nuclear fission reactions

Critical mass

minimum mass of fissionable material needed for a self-sustaining chain reaction

Subcritical mass

less than minimal mass needed for a self sustaining chain reaction, meaning that too many neutrons will escape and no chain reaction will occur

Atomic bomb

must contain a critical mass of uranium 235 (critical mass must be kept in separate place before detonation)

Group 1A ions

Hydrogen, Lithium, Sodium, Potassium, Rubidium, Cesium

Group 11A ions

Beryllium, Magnesium, Calcium, Strontium, Barium

Group 111A ions

Aluminum, Boron

Miscallaneous

Silver (Ag+), Ammonium(NH4+), Zinc(Zn2+), Cadmium (Cd2+)

Positive ions with multiple charges

Iron 11 - Ferrous

Iron 111- Ferric

Copper 1- Cuprous

Copper 11- Cupric

Cobalt 11- Cobaltic

Cobalt 111- Cobaltic

Mercury 1- Mercurous

Mercury 11- Mercuric

Manganese 11- Manganous

Manganese 111- Manganic

Tin 11- Stannous

Tin 1111- Stannic

Lead 11- Plumbous

Lead 1111- Plumbic

Group 1V A ions

Carbide, Sillicide

Group VA ions

Nitride, Phosphide

Group V1A ions

Oxide, Sulfide

Group V11A ions

Fluoride, Chloride, Bromide, Iodide

Group 1A ions (again)

Hydride (hydrogen with a -1 charge)

Chloride oxyhalogens

hypochlorite: ClO-

chlorite: ClO2-

chlorate: ClO3-

Perchlorate: ClO4-

Bromide oxyhalogens

Hypobromite: BrO-

Bromite: BrO2-

Bromate: BrO3-

Hypobromate: BrO4-

Iodide oxyhalogens

Hypoiodite: IO-

Iodite: IO2-

Iodate: IO3-

Periodate: IO4-

Miscellaneous Polyatomic Ions Part 1

Peroxide: O2-

Hydroxide: OH-

Carbonate: CO3 2-

Bicarbonate: HCO3 -

Monohydrogen phosphate: HPO4 2-

Dihydrogen phosphate: H2PO4 -

Arsenite: AsO3 3-

Arsenate: AsO4 3-

Chromate: CrO4 2-

Dichromate: Cr2O7 2-

Phosphite: PO3 3-

Phosphate: PO4 3-

Acetate: C2H3O2 -

Miscellaneous Polyatomic Ions Part 2

Cyanide: CN-

Thiocyanate: SCN-

Cyanate: OCN-

Nitrite: NO2-

Nitrate: NO3-

Sulfite: SO3 2-

Sulfate: SO4 2-

Thiosulfate: S2O3 2-

Permanganate: MnO4-

Oxalate: C2O4 2-

Phthalate: C8H4O4 2-

Sillicate: SiO4 4-

Borate: BO3 3-

1 mole

6.022 × 10 ^ 23 atoms

Molar mass

The mass in grams of 1 mole

Mole Road Map

number of atoms ——> 6.022× 10 ^ 23 ——→ mol —→ molar mass —→ mass(g)

HOFBrINCl

H2, O2, F2, Br2, I2, N2, Cl2

Molecular formula

show the exact numbers of atoms; true formulas of molecules

Empirical formula

show the ratio of atoms

Molecular mass

sum of the atomic masses in amu of all the atoms in a molecule, the molar mass is the same mass but in grams

Limiting Reagant

Reactant depleted first

Theoretical yield

Amount of product that forms if all the limiting reagent has reacted

Actual yield

amount of product that is actually made

Percent yield

comparison of actual yield to theoretical yield; actual yield/theoretical yield *100

excess reagant

reactant left at the end of the reaction

stochiometry

the mass relationships among reactants and products in chemical reactions

Synthesis

A+X=AX

ex; sodium+chlorine

Decomposition

AX= A+ X

FeCl3 —→ 2Fe + 3Cl2

** metal hydroxide —→ metal oxide + water

Double displacement

(AX + BY —→ AY+ BX)

*remember solubility rules!!

Solubility Rules

1. All alkali metal compounds are soluble

2. All ammonium compounds are soluble

3. All compounds containing nitrate are soluble

4. Most hydroxides are insoluble EXCEPT alkali metals

5. Most chlorides, bromides, iodides are soluble

   EXCEPT Ag+, Hg2 2+, Pb 2+

Cation Displacement

AX +B —→ BX+A

(single element must be more reactive than the element it replaces, otherwise NR)

Anion Displacement

AX + Y —→ AY + X

Reactivity: F2> Cl2> Br2 > I2

Combustion

CxHyOz + O2 —→ CO2 + H2O

Percent by mass

mass solute/mass solution * 100

Percent by volume

vol solute/ vol solution * 100

Molarity

mol solute/ L solution

Preparation of a solution of a known molarity

1. Calculate mass required

2. Weigh; put in volumetric flask

3. Add distilled water; swirl to dissolve

4. Add water after solute dissolves

Quantitative Analysis updated solubility rules

1. all compounds containing NO3-, CLO3-, CLO4- are soluble

2. Most OH- insoluble; alkali metals and Ba are exceptions

3. All CO32-, PO4 3-, S 2- compounds are insoluble

4. Most SO42- are insoluble; Ba, Hg, Pb exceptions

James Maxwell

Proposed accelerating electrons —→ electromagnetic waves

Verified by Hertz experiment ( created first radio transmitter and receiver)