By Alec “Dr. Bathroom” Levy Niteesh “The Yellow Dart” Chitturu

Nomenclature

 Cation-Electron-deficient atom/molecule (+ charge)  Atoms in transition metals, alkalines, alkaline earths typically form cations  Ex.: Ca 2+ Fe 2+ Li +  Transition metals include Roman Numerals except Zn 2+ Ni 2+ Ag +  Anion-Electron-surplus atom/molecule (- charge  Form in halogens, chalcogens, pnictogens, and polyatomic molecules  Ex: F O 2 N 3 SO 2-

Nomenclature

 Atom-smallest unit of element that retains its properties, includes mono- and poly  Compound-2 different elements bonded together  Molecule-Covalently bonded atoms  Salt-Combination of 2 or more ions bonding to form a neutral compound  Same thing as a neutral ionic compound, which consists of a metal cation and nonmetal anion

Acid Nomenclature

 Acids-Contains H + cation  -ide  hydro_____ic acid  -ate  _____ic acid  -ite  ______ous acid  Ex: Sulfide=hyrdosulfuric acid  Ex: Sulfate=sulfuric acid  Ex: Sulfite=sulfurous acid

Bonding & Formulas

 Covalent compounds-2 or more nonmetals, come first in formula, except for F and O  Organic compounds-Hydrocarbons, consists of only C and H  Alkanes-Carbon backbone, fills in excess with H, ends with –ane 1=meth 2=eth 3=prop 4=but 5+=binary  Alcohols-Adds O to chain, ends in -anol

Common Anions

   1  H (Hydride ion), F Ion), Br (Bromide ion), I (Fluoride ion), Cl (Iodide ion), CN (Chloride (Cyanide ion), OH ClO 3 ( Hydroxide ion), C 2 H 3 O 2 (Chlorate ion) ClO 4 (Nitrate ion), MnO 4 (Acetate ion), (Perchlorate ion), NO (Permanganate ion) 3 2  O Cr 2 O 7 2 2 (Oxide ion), O 2 2 ion), CO 3 2 (Peroxide ion), S (Carbonate ion), CrO (Dichromate ion), SO 4 2 4 2 2 (Sulfate ion) (Sulfide (Chromate ion), 3  N 3 (Nitride ion), PO 4 3 (Phosphate ion)

Atomic Structures

 Angstrom-Å=10 -10 meters=size of an atom  Proton-Subatomic particle with positive charge of 1, in the nucleus  Neutron-Subatomic particle with neutral charge, in the nucleus  Electron-Subatomic particle with negative charge of 1, in energy orbitals  Protons and Neutrons consist of 99.99% of mass  1 electron=1/1800 proton

Isotopic Notation



A Z

X

q

Isotopes have same number of protons but different number of neutrons and are chemically identical  A-Mass number=protons+neutrons  q-Charge=electron+protons  Z-Atomic number=protons

Isotopic Abundance/Molar Mass

 To calculate isotopic abundance from molar mass  Ex: Average mass of sample is 1.614 g/mol. Molar mass of hydrogen-1 is 1.00782, molar mass of deuterium is 2.01410. What is the abundance of the two isotopes?

 Answer: hydrogen-1=39.76%, deuterium=60.24%

Balancing reaction equations

  Given: C 24 Answer : C H 24 46 H O 46 3 + O 2  CO 2 O 3 + H 2 O + 34O 2  24CO 2 + 23H 2 O It’s 1.5-glyceride Isn’t Chemistry pHun?

Mass-mole relationship

 1 mole of a substance is equal to 6.022 x 10 23 particle  1 mole of substance is equal to its amu but in grams  Poly-atomic substances moles are a sum of its constituents  Ex: C 24 H 46 O 3 has 24 C, 46 H, and 3 O. Thus: (12.0107 x 24) + (1.00794 x 46) + (15.9994 x 3)=382.62024 g/mol

Empirical formulas/ percent composition

 Given percent composition by mass spectrometry, the empirical formula of a molecule is what?

 54.50% carbon, 13.72% hydrogen, 31.78% nitrogen  Assume given values are in grams, then calculate for moles  Divide moles by lowest value of moles  Answer is subscript of empirical formula  To determine molecular formula, molar mass must be known Ex: 88.15 g/mol

Limiting/Excess Reactants

 To determine limiting reactant, balance equation and solve for both reactants  Lower value is limiting, the higher one is excess

Percent Yield

 Percent Yield =( actual or experimental value)/(theoretical values determined by limiting reactant) Easy? Yes/No?

IT’S A GAS GAS GAS!!!

 Qualitative: pressure, volume, number of moles, and temperature are at work, along with R, the gas constant  Boyle’s Law: Volume of gas at constant temperature is inversely proportional to pressure V=k ∙ 1/p  Charles’s Law: Volume of gas at constant pressure is directly proportional to absolute temperature V=k ∙ T  Avogadro’s Law: Equal volumes of gases at equal temperature and pressure contains equal number of molecules, and volume of gas at constant pressure and temperature is directly proportional to number of moles V=k ∙ n

Ideal Gas Law

 PV=nRT  R is the ideal gas constant, equal to 0.08206 L atm/mol-K  Volume of a gas at STP is 22.41 L  To calculate density, calculate concentration (mol/L) and convert to g/cm 3 (1 mL=1 cm 3 )

PV=nRT in action…

 Given: pressure is 1020 torr, volume is 1.5 L, and temperature 37. 4 degrees Celsius, mass of sample is 2.530 g, what is the molar mass?

 1020 torr=1.342 atm  37.4 degrees Celsius=310.55 degrees Kelvin  n=PV/RT=.07899 mol  Molar mass=g/mol=2.530 g/ .07899 mol= 32.03 g/mol  It’s O 2 !

Partial Pressure

 Dalton’s law of partial pressures: Total pressure of a mixture of gases equals the sum of the pressures that each would exert alone  Applies only for ideal gases!!!

  P t = P 1 + P 2 + P 3 …. + P n Mole fraction (X)=Moles of given gas/Total Moles of gas  P n = X n P t

Kinetic Molecular Theory

 Gases consist of large amounts of molecules in continuous random motion  The molecules have negligible volume compared to the total volume the gas occupies  There are negligible attractive or repulsive forces between those molecules  The average kinetic energy of the molecules remains constant (the collisions are perfectly elastic)  The molecule’s average kinetic energy is proportional to the absolute temperature

Root Means Square Speed

 Velocity=u=√(3RT/M)  R=gas constant  T=absolute temperature  M=kg/mol  Lighter molecules move on average faster than heavier molecules

Graham’s rates of effusion/diffusion

 Effusion: Gas escaping into a vacuum  Diffusion: Gas mixing into another gas, going from high concentration to low concentration  Rate A escapes/Rate B escapes= u a /u b = √M b /M a

Van der Waals’s equation

 Real (non-ideal) gas equation  Molecules DO occupy space, thus takes up volume  Molecules DO sometimes attract each other  Correction factors are needed   (P real + a(n/v) 2 )(V container – bn)=nRT a=attractive coefficient, expressed in atm ∙ L 2 /mol 2  b=volume coefficient, expressed in L/mol (Das Good?)

Fin

Dr. Bathroom and the Yellow Dart…Away!?!