Drexel University

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...

What is the Van Deemter equation? - correct answers H = A + B/ux + Cux Independent of flow velocity - correct answers A term Inapplicable in open tubular columns - correct answers A term Inversely proportional to flow rate - correct answers B term Proportional to temperature - correct answers D (diffusion coefficient) / B term (longitudinal diffusion) Proportional to linear flow velocity - correct answers C term Inversely proportional to temperature - correct answers C term (th...

A triplet state is an ___________________ state in which the electron _______ is _______________ paired with the electron remaining in the _______________. - correct answers electronic excited spin no longer ground state Name the regions of the electromagnetic spectrum in order of longest to shortest wavelength. (Hint: longest time to kill you to shortest time to kill you) - correct answers radiowave microwave infrared visible ultraviolet x ray gamma ray Name the regions of the el...

What is a junction potential? - correct answers When dissimilar electrolyte solutions are in contact, a voltage difference, called a junction potential, will usually develop at their interface. What is a fundamental limitation on the accuracy of direct potentiometric measurements? Why? - correct answers Junction potential; we do not know its contribution to voltage What is alkaline error when using a pH measuring glass electrode? - correct answers Too much Na+ relative to H+, electrode wil...

What was solvent-solvent extracted used for in experiment 1? - correct answers -to extract ethanol from alcoholic beverages (busch, busch light, and a non-alcoholic drink) Why can you not do a direct analysis on alcohol? - correct answers because it also contains carbs, proteins, and water and these things could interfere with the analysis How do you combat this problem (in exp 1)? - correct answers -isolate the compound of interest from the rest of the compounds in the sample what is a...

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 ...

Arrhenius acid - correct answers increases [H+] in water Arrhenius base - correct answers increases [OH-]

What is the Arrhenius definition of an acid/base? - correct answers acid: increases [H30+] in solution base: increases [OH-] in solution What is the Bronsted-Lowry definition of an acid/base? - correct answers acid: donates H+ base: accepts H+ What is the Lewis definition of an acid/base? - correct answers acid: e- pair acceptor base: e- pair donor What are the 7 strong acids? - correct answers HCl, HBr, HI, HNO3, HClO3, HClO4, H2SO4 (first H only) What functional group do the str...

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...

Van Deemter Equation - correct answers A-term: multiple paths - correct answers - only affects packed columns - A term goes down with uniformly packed columns - smaller SP particles decrease A - no A term in OT because there are no particles A term band broadening - correct answers different particles take different paths with varying lengths and times to get out of column B term: longitudinal diffusion - correct answers - smaller molecules diffuse more than larger molecules - incr...