Fundamental Concepts in Chemistry: Atomic Theory, Quantum Mechanics, and Thermodynamics, Exams of Nursing

Download Fundamental Concepts in Chemistry: Atomic Theory, Quantum Mechanics, and Thermodynamics and more Exams Nursing in PDF only on Docsity! CLEP Chemistry EXAM LATEST QUESTIONS AND CORRECT DETAILED ANSWERS | AGRADE John Dalton - ANSWER>> Proposed that matter is composed of atoms; these atoms have different identities called elements, which combine to form compounds; measured masses of reactants and products. J.J. Thompson - ANSWER>> Observed deflection of particles in a cathode ray tube; proposed that atoms are composed of positive and negative charges; developed the plum pudding model of the atom Robert Millikan - ANSWER>> Calculated the charge-to-mass ratio of electrons using oil drops falling in an electric field; surmised the charge of a single electron Ernest Rutherford - ANSWER>> Used the deflection of alpha particles in a cathode ray tube to discover that most of the atom is empty space, with protons and neutrons centered in the nucleus. Niels Bohr - ANSWER>> Determined that electrons exist around the nucleus at a fixed radius; electrons with higher energy exist farther from the nucleus. Electrons give off electromagnetic radiation when moving between energy levels. Max Planck - ANSWER>> Determined that energy is quantized, or composed of discrete bundles. 6.63 x 10^-34 J*sec - ANSWER>> Planck's Constant (h) 3.00 x 10^8 m/sec - ANSWER>> Speed of Light (c) E = hv - ANSWER>> Energy of a Photon Formula (1) E = hc / wavelength - ANSWER>> Energy of a Photon Formula (2) Louis DeBroglie - ANSWER>> Combined Einstein's relationship between mass and energy and the relationship between velocity and the wavelength of light. All particles with momentum have a corresponding wave nature. Wavelength = h / mv - ANSWER>> Wavelength of Particles Formula Heisenberg's Uncertainty Principle - ANSWER>> It is impossible to simultaneously know the position and momentum of an electron. Erwin Schrodinger - ANSWER>> Attributed a wave function to electrons, describing the probability of where an electron might exist. Orbitals - ANSWER>> Regions of high probability where electrons might exist; broken into four levels: s, p, d, or f Atomic Mass - ANSWER>> The cumulative mass of all the particles in the atom; found by adding the masses of the protons and neutrons. Units: Atomic Mass Units (AMU) Example: helium = 2 protons + 2 neutrons = 4 AMU Atomic Number - ANSWER>> The number of protons in the nucleus of an atom, or the total nuclear charge. Also the number of electrons surrounding the nucleus. Isotopes - ANSWER>> Atoms with the same number of protons but different numbers of neutrons. Example: carbon-12 (6 neutrons) vs carbon-14 (8 neutrons) Atomic Weight - ANSWER>> Molar mass of the element, or the mass in grams of one mole of atoms Pauli Exclusion Principle - ANSWER>> No two electrons can occupy the exact same energy level or have the same set of four quantum numbers Quantum numbers - ANSWER>> 1. Principal (n) 2. Angular Momentum (l) 3. Magnetic (ml) 4. Magnetic Spin (ms) Principal Quantum Number - ANSWER>> The shell or energy level an electron occupies; values from 1-7. Electrons with higher values are farther from the nucleus. Angular Momentum Quantum Number - ANSWER>> The subshell the electron occupies; describes the shape of an electron's orbital. n = 1: l = 0 (s) n = 2: l = 0 (s), 1 (p) n = 3: l = 0 (s), 1 (p), 2 (d) n = 4: l = 0 (s), 1 (p), 2 (d), 3 (f) Magnetic Quantum Number - ANSWER>> Represents the orbital position. l = 0: ml = 0 (1 possible s orbital) l = 1: ml = -1, 0, 1 (3 possible p orbitals) l = 2: ml = -2, -1, 0, 1, 2 (5 possible d orbitals) l = 3: ml = -3, -2, -1, 0, 1, 2, 3 (7 possible f orbitals) Magnetic Spin Quantum Number - ANSWER>> Each orbital contains at most 2 electrons: one with a positive spin (+1/2) and one with a negative spin (-1/2) (The volume of a gas is inversely proportional to its pressure, when temperature is constant) - ANSWER>> Boyle's Law V1T2 = V2T1 (The volume of a gas is directly proportional to temperature, when pressure is constant) - ANSWER>> Charles's Law P1T2 = P2T1 (The pressure of a gas is directly proportional to temperature, when volume is constant) - ANSWER>> Law of Gay-Lussac Ptotal = P1 + P2 + ... + Pn (The total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the gases in the mixture.) - ANSWER>> Dalton's Law V1n2 = V2n1 (The volume of a gas is proportional to the number of moles of gas present when temperature is constant) - ANSWER>> Avogadro's Law PV = nRT (Pressure x Volume = number of gas moles x ideal gas constant x absolute temperature) - ANSWER>> Ideal gas law formula 0.082 L*atm / K*mol - ANSWER>> Ideal gas constant (R) 273 K; 1.0 atm; 1.0 mol gas = 22.4 L gas - ANSWER>> Standard Temperature and Pressure (3 components) P(mm) = dRT (Pressure x molar mass = density x ideal gas constant x absolute temperature) - ANSWER>> Ideal gas law formula (in terms of density) 1/2 (ma x va^2) = 1/2 (mb x vb^2) (Two gases at the same temperature and pressure will have the same kinetic energy; v = velocity; m = mass) - ANSWER>> Graham's Law ra^2 / rb^2 = Mb / Ma (gas molecules of smaller molar mass move faster than gas molecules of larger molar mass) - ANSWER>> Graham's law of effusion [P + (an^2 / V^2)](V - nb) = nRT (Pressure + number of moles squared x intermolecular attraction constant / volume of gas squared, x Volume - no. moles x space occupied by one mole, = number of moles x ideal gas constant x temperature) - ANSWER>> Van der Waals Equation for real gases Phase diagram - ANSWER>> Shows the state of a substance at any given temperature and pressure Critical point - ANSWER>> The temperature and pressure point on a phase diagram above which the substance must exist as a gas. Triple point - ANSWER>> The temperature and pressure point on a phase diagram at which a substance may exist in all three phases Vapor pressure curve - ANSWER>> Defines the boundary between the liquid & gas phases on a phase diagram Crystalline solids - ANSWER>> Composed of structural units bounded by a specific geometric pattern. Example: table salt Unit cell - ANSWER>> The smallest repeating unit in a crystalline solid Simple cubic unit cells - ANSWER>> These have one atom at each of the corners of the cube; containing a total of one atom per unit cell. Face-centered crystal - ANSWER>> A simple cubic unit cell with one additional atom shared between two unit cells on each face of the cube; a total of three atoms per unit cell. Body-centered crystal - ANSWER>> A simple cubic unit cell with one additional atom in the center of the cube, for a total of two atoms per unit cell Amorphous solids - ANSWER>> These don't display a specific geometry; example: glass Solvation - ANSWER>> The interaction of solvent molecules with solute molecules to form loosely bonded combinations. Hydration - ANSWER>> The solvation process when water is the solvent. Miscible solutions - ANSWER>> These occur when one substance is soluble in all proportions with another substance. Saturation - ANSWER>> A solid solute is in equilibrium with dissolved solute. Solubility - ANSWER>> The molar concentration of dissolved solute at saturation Supersaturation - ANSWER>> A solution that contains more solute than required for saturation P = kC (The amount of gas that can dissolve in a liquid is directly proportional to the partial pressure of the gas above the liquid.) - ANSWER>> Henry's Law M = moles solute / liters solution - ANSWER>> Molarity formula pH = - log [H+] - ANSWER>> pH formula Molality = Moles solute / kilograms solvent - ANSWER>> Molality formula mole fraction = moles solute / total solution moles - ANSWER>> Mole Fraction formula P = XP0 (vapor pressure of solution = vapor pressure of solvent x mole fraction of solvent) - ANSWER>> Raoult's Law ∆T = (kb)(m)(i) (change in solvent boiling point = molal boiling point constant of solvent x molality of solute x van't hoff factor of solute) - ANSWER>> Boiling point elevation; or, change in solvent boiling point ∆T = (kf)(m)(i) (change in solvent freezing point = molal freezing point constant of solvent x molality of solute x van't hoff factor of solute) - ANSWER>> Freezing point depression; or, change in solvent freezing point πV = nRTi (osmotic pressure x volume of solution = moles of solute x ideal gas constant x temperature x Van't Hoff factor of solute) - ANSWER>> Osmotic pressure formula Arrhenius Theory - ANSWER>> Acids ionize in water to donate protons; bases ionize in water to produce hydroxide ions. Bronsted-Lowry Theory - ANSWER>> Acids donate protons and bases accept protons; a proton moves from one compound to the other. Lewis theory - ANSWER>> An acid is an electron-pair acceptor, and a base is an electron-pair donor. Neutralization - ANSWER>> The process where an Arrhenius acid and base are combined to form a salt and water. Amphoteric - ANSWER>> Compounds that can act as either acids or bases Precipitation reactions - ANSWER>> Occur when soluble reactants are mixed together to form an insoluble product (see solubility rules) Net ionic reaction - ANSWER>> A reaction that shows only ions that combine to form the precipitate. Spectator ions - ANSWER>> Ions that remain dissolved in a precipitation reaction. Oxidation reaction - ANSWER>> An atom increases control over an electron; a loss of electrons Reduction reaction - ANSWER>> An atom decreases control over an electron; a gain of electrons Combustion reaction - ANSWER>> Oxygen combines with another compound to form water and carbon dioxide Synthesis reaction - ANSWER>> Two or more simple compounds combine to form a more complicated one Decomposition reaction - ANSWER>> A complex molecule breaks down to make simpler ones. Single displacement reaction - ANSWER>> One element trades places with another element in a compound.