Chem 241 correct - Study guides, Class notes & Summaries

What are the wavelengths of visible light? - correct answers 400 - 800 nm How do X-Rays affect electrons? - correct answers Electronic Transitions of Core Electrons (Breaks chemical bonds and ionizes molecules) How does UV- VIS affect electrons? - correct answers Electronic Transitions of Valence Electrons (Vibrational + Rotational as well) How does IR affect electrons? - correct answers Vibrational Transitions (Rotational as well) How do Microwave waves affect electrons? - correct a...

History of chromatography (ch 23) - correct answers -Greek word "chromatus" for color -Tswett (1903) first separated plant pigments Applications - correct answers Breast milk, water analysis, urinalysis for drug doping Goals of separation - correct answers Recovery of product, purity of product Type, SP, MP - correct answers 1. Adsorption: one polar substance sticks to another polar substance. Solid SP, gas or liquid MP 2. Partition: dissolving of 2 similar liquids. Liquid SP, gas o...

Assume you have a mixture that is 20% acetone 50% cyclohexane, and 30% dimethyl carbonate. Sketch a GC of this mixture. Label each peak and make each peak roughly the correct size. - correct answers On a graph of abundance vs time, acetone comes off first, then cyclohexane, then dimethyl carbonate. The sizes are in a 2:5:3 ratio. The pKa of benzoic acid is 4.2. At a pH of 2.0, 4.2, and 12.0, in what state(s) of protonation will benzoic acid be? And in which layer (water or organic) would...

Extraction - correct answers Transfer of a solute from one phase to another Eluent - correct answers Fluid entering the column Partition Chromatography - correct answers Separation based on solute dissolving into stationary liquid Ion-Exchange Chromatography - correct answers Separation based on charge, stationary phase is made of either negatively or positively charged beads Size Exclusion Chromatography - correct answers Separation based on molecular size, larger molecules elute fi...

Crystalline solids have what? - correct answers have highly ordered structures In liquids, the active IMF are...? - correct answers strong enough to hold molecules relatively close together but not strong enough to keep molecules from moving past each other In which of the following molecules is H bonding likely to be the most significant component of the total IMF? - correct answers CH3OH What substance has London only? - correct answers Kr What substance has dispersion only as its ...

Which of the following shows the correct order of increasing strength as an oxidizing agent? - correct answers K+ (aq) < MnO4- (aq) < O3 (g) What is the pH of the standard hydrogen electrode? - correct answers pH = 0 What is the correct cell notation for the reaction below? Cu2+ (aq) + Pb (s) ⇔ Cu (s) + Pb2+ (aq) - correct answers Pb (s) I Pb2+ (aq) II Cu2+ (aq) I Cu (s) Calculate standard cell potential for the following reaction: MnO4- (aq) + 8 H+ (aq) + 5 Fe2+ ⇔ Mn2+ + 4 ...

What is the maximum amount of time a specific solute band will spend in the mobile phase of a chromatography column? - correct answers tm Which of the following is NOT an advantage of the use of OPEN TUBULAR columns (capillaries) over packed columns? - correct answers A. smaller plate height (H) B. [[[[greater column capacity]]]] C. faster flow rates D. No A-term in the van Deemter equation E. higher separation efficiency Which mode of chromatography separates compounds based on th...

How do transmittance, absorbance, and molar absorptivity differ? Which one is proportional to concentration? - correct answers *transmittance* = (P/P0) *absorbance* = log(T) absorbance is proportional to concentration Why is it most accurate to measure absorbances in the range A = 0.3-2? - correct answers If absorbance is too high, too little light reaches the detector for accurate measurement If absorbance is too low, there is too little difference between sample and reference for a...

Internal Conversion - correct answers 7 Vibrational Relaxation - correct answers Squiggles Fluorescence - correct answers 10 phosphorescence - correct answers 4 1 meter equals how many nanometers - correct answers 1*10^9 nanometers Lowest to highest photon energy - correct answers radiowave, microwave, infrared, visible, ultraviolet, X-ray, gamma-ray Infrared absorption - correct answers molecular vibration transition UV absorption - correct answers valence electron transiti...

What acid is the primary catalyst in the making of the most explosives used in North America? - correct answers Nitric Acid What is ANFO? - correct answers Ammonium Nitrate Fuel Oil What type of explosive is used mainly for military purposes? - correct answers RDX What is most nitric acid used to produce? - correct answers Ammonium Nitrate Fertilizer Where was the catastrophic nitric acid explosion of 1947? - correct answers Texas City, TX What chemical is produced in the largest ...