Atomic Structure, Compounds, and Chemical Formulas

Atomic Structure and Chemistry Fundamentals

Organic chemistry is the science of matter. All matter occupies space. Plasma is when atoms are in a high-temperature environment.

• Elements: A single type of atom that cannot be transformed into simpler substances.
• Compounds: Substances formed by different types of atoms combined in a constant ratio.
• Homogeneous: Has a single phase, and components are indistinguishable (H₂O + C₆H₁₂O₆). Can be separated by evaporation or distillation.
• Heterogeneous: Components can be distinguished from each other.
• Phase: A portion of matter with definite limits. Can be separated by filtering or decanting.

d = mass / volume

Prefixes: milli (m) - 10^-3 / micro (μ) - 10^-6 / nano (n) - 10^-9

1 kg = 1000 g and 1 dozen = 12 units

Temperature Conversions:

• C° = 5 / 9 (F° - 32)
• K° = C° + 273.15
• F° = 9 / 5 (C° + 32)

Atomic Structure

The atomic theory of Dalton (1808) states that matter is made up of tiny particles called atoms.

• Nucleus: Made up of protons and neutrons.
• Electrons: Move away from the nucleus.

Particle Properties:

• Proton (P⁺): Charge +1, Location: Nucleus, Mass: 1.67 x 10^-24 g
• Neutron (N⁰): Charge 0, Location: Nucleus, Mass: 1.67 x 10^-24 g
• Electron (e^-): Charge -1, Location: Exterior, Mass: 9.11 x 10^-28 g

Example: O_8p+ = 8 x 1.97 x 10^-19 = 1.576 x 10^-18

Atoms differ in the number of neutrons and protons in their nucleus.

^A_ZC, e.g., ¹²₆C

⁴⁰₁₉K⁺: P⁺ = 19, N⁰ = 21, e^- = 18

Isotopes are atoms of the same element with a different number of neutrons in the nucleus.

Electron Configuration: 1s²2s²2p⁶3s²3p⁶4s²3d²

Quantum Numbers:

• m = -1 for 3d²
• s = 0 / p = 1 / d = 2 / f = 3
• l = 2, then the sequence is -2, -1, 0, +1, +2
• If s = +1/2, the rest are -1/2
• n = 3
• s = +1/2

Calculations with Moles and Atoms

Calcium has a mass of 40.8 g/mol. How many atoms are in 10g of Ca?

40.8 g contains 6.02 x 10²³ atoms
10 g contains X atoms
X = 1.475 x 10²³ atoms

Epinephrine: 59.0% C, 7.1% H, 26.2% O, 7.7% N

C = 59/12 = 4.91
H = 7.1/1.01 = 7.02
O = 26.2/16 = 1.63
N = 7.7/14 = 0.55
Divide by the smallest value (0.55):
C₉H₁₃O₃N

How many molecules of quinine (C₂₀H₂₄O₂N₂) are in 1.08 g of quinine? How many moles?

C = 12 x 20 = 240
H = 1.01 x 24 = 24.24
O = 16 x 2 = 32
N = 14 x 2 = 28
Total molar mass = 324.24 g/mol

324.24 g contains 6.02 x 10²³ molecules
1.08 g contains X molecules
X = 2.005 moles
XX = 2.01 x 10²¹ molecules

315 g of acetic acid (CH₃COOH):

a) Moles of CH₃COOH
C = 12 x 2 = 24
H = 1 x 4 = 4
O = 16 x 2 = 32
Molar mass = 60.04 g/mol
Moles = mass / molar mass = 315 g / 60.04 g/mol = 5.246 moles

b) Moles of each element
1 mol CH₃COOH contains 2 mol C
5.246 mol CH₃COOH contains X mol C
X = 10.492 mol C

c) Number of atoms of each element
315 g x (1 mol CH₃COOH / 60.04 g/mol) x (2 mol C / 1 mol CH₃COOH) x (6.02 x 10²³ atoms / 1 mol C)
X = 6.32 x 10²⁴ C atoms

SO₃:
S = (32 x 1 / 80) x 100 = 40%
O = (16 x 3 / 80) x 100 = 60%

Ionic Compounds and Nomenclature

Ionic compound, ANION

• K⁺ = Potassium ion
• N^3- = Nitride
• O^2- = Oxide
• Br^- = Bromide
• CN^- = Cyanide
• Fe²⁺ = Ferrous ion
• Fe³⁺ = Ferric ion
• FeCl₂ = Ferrous chloride
• Mn²⁺: Manganese oxide MnO (II)
• N₂O₄ = Nitrogen tetroxide
• CH₄ = Methane
• HCl = Hydrochloric acid
• H₂SO₄ = Sulfuric acid

Acid Nomenclature:

• -1, Hypo-ous
• -2, -ous
• -3, -ic
• -4, Per-ic

Anion Nomenclature:

• -1, Hypo-ite
• -2, -ite
• -3, -ate
• -4, Per-ate

Examples:

• NaOH = Sodium hydroxide
• KOH = Potassium hydroxide
• Ba(OH)₂ = Barium hydroxide
• ClO^- = Hypochlorite
• ClO₂^- = Chlorite
• ClO₃^- = Chlorate
• ClO₄^- = Perchlorate
• Mn(OH)₂ = Manganese hydroxide
• CO₂ = Carbon dioxide
• Al₂O₃ = Aluminum oxide
• Cu₂O = Cuprous oxide
• HBrO = Hypobromous acid
• Fe₂O₃ = Ferric oxide
• KClO₂ = Potassium chlorite
• NH₄OH = Ammonium hydroxide
• MnO₂ = Manganese dioxide
• FeSO₄ = Iron sulfate
• H₂Se = Selenhydric acid
• CaCO₃ = Calcium carbonate
• NH₃ = Ammonia
• KClO₃ = Potassium chlorate
• HCl = Hydrochloric acid
• KMnO₄ = Potassium permanganate
• RbH = Rubidium hydride
• CsBr = Cesium bromide
• HF = Hydrofluoric acid
• CuSO₄ x 5H₂O = Copper sulfate pentahydrate
• Ni(OH)₃ = Nickel hydroxide
• KHCO₃ = Potassium bicarbonate (Potassium hydrogen carbonate)
• NaHSO₄ = Sodium bisulfate (Sodium hydrogen sulfate)
• HClO₂ = Chlorous acid
• Mg(ClO₂)₂ = Magnesium chlorite
• Au₂Se₃ = Auric selenide
• ZnCl₂ = Zinc chloride
• Barium hydroxide = Ba(OH)₂
• Perbromic acid = HBrO₄
• Silver nitrate = AgNO₃
• Hydrogen sulfide = H₂S
• Sodium silicate = Na₂SiO₃
• Aluminum sulfate = Al₂(SO₄)₃
• Calcium carbonate = CaCO₃
• Nitrogen dioxide = NO₂
• Hydrogen peroxide = H₂O₂
• Mercuric oxide = HgO
• Magnesium phosphate = Mg₃(PO₄)₂
• Aluminum fluoride = AlF₃