CHM 1045 - exam 3 Questions and Answers 100% Pass

___________ and _________ are inversely proportional; _________ and _______ are directly proportional - frequency and wavelength ; frequency and energy 1st Law of Thermodynamics - delta-U = q + W heat transferred + work done by system on surroundings - W is positive if work is done on the system (by surrounding) - W is negative if work is done by the system A system doing work pushes back on surroundings, it ___________. When surroundings do work, pushes back on system, it _________ . - expands; compresses Amplitude - A : intensity -> 1/2 height between peaks and troughs - light : brightness - sound : loudness Angular Momentum Quantum Number (l) - - subshells - describes the shape of orbital Atomic spectroscopy - suggest wave nature for subatomic particle - the study of light that is absorbed or emitted by atoms - atoms of different elements emit light as characteristic color, Hg= blue, He = violet, H = red Aufbau Principle - to build up - electrons enter subshell of lowest energy subshell until that subshell is filled, then they begin to fill next lowest energy subshellbomb calorimeter - operate at constant volume used to measures reactions that yield large amounts of heat and gaseous products q_rxn = - (q_surroundings + q_cal) Calorie (cal) - amount of energy required to raise 1g of H2O 1C; depends on pressure and temp - I kcal describes the amount of energy in food that your body can convert into its own form of energy (ATP) Calorimeter - a device used to measure amount of heat involved in chemical or physical process - exothermic reaction releases heat (system) surroundings will increase Calorimetry - the technique used to measure amount of heat transferred to or from a substance Core electrons - The electrons in the inner shells - Shells get completely filled for ex/ Ne = 1s^2 2s^2 2p^6 D block for electrical configuration - groups 3 -12 - 5 orbitals - 10e^- - for n values use (n-1) Density - d = g/mL - increasing temperature decreases density - only bubbles that are less dense than the water will float Diffraction - a phenomena of waves; when wave encounters barrier, it will bend around barrierElectromagnetic radiation - a spectrum of electromagnetic waves of varying speed, size, energy Electron configuration for anions - electrons are added in order predicted by Aufbau Principle P: [Ne] 3s^2 3p^3 P^3-: [Ne} 3s^2 3p^6 Electron configuration for main group cations - less e^- then neutral atom - the last e^- added is 1st e^- removed so Na = Na+: 1s^2 2s^2 2p^6 Electron configuration for transition metal cations - electrons in ns orbital removed prior to e^- in (n-1)d orbital Fe: [Ar} 4s^2 3d^6 Fe^2+ : [Ar] 3d^6 Fe^3+ : [Ar] 3d^5 Emission spectrum - the distinct wavelengths emitted by an element - can use this to identify elements present in sun Endothermic process - absorbs heat (enters) Energy - the capacity to do work - causing matter to move against an opposing force Enthalpy - a state function that describes system's energy as heat (H) H = U + PV - at constant pressure: delta-H = delta-U + P delta-V delta-H = q_p + W-W = q_p - expansion workW = - P delta-V - internal energy delta-U = q + W