Chem 241 - Study guides, Class notes & Summaries

If you are unsure which layer of your separatory funnel is the organic layer and which is the aqueous layer, which of these is the safest way to figure it out? - correct answers Add a few drops of water to each layer to see if the water mixes in (aqueous layer) or forms a separate layer (organic) How do you know when you have used a sufficient amount of sodium sulfate? - correct answers When some of the sodium sulfate is powdery or free flowing When should you throw out the layer from the ...

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 ...

carrier gas - correct answers MP gase in GC cold trapping - correct answers Splitless gas chromatography injection technique in which solute is condensed far below its boiling point in a narrow band at the start of the column. electron capture detector - correct answers gas chromatography detector that is particularly sensitive to compounds with halogen atoms, nitro groups, and other groups with high electron affinity flame ionization dectector - correct answers gas chromatography detec...

lab 7: what sort of condenser should you use and why? - correct answers a water condenser instead of an air condenser because it is better at preventing your solvent and or products from evaporating how can you reduce the health risk of silica gel? - correct answers keep it wet with solvent so less powder gets in the air, handle the gel in the fume hood, I'm some gel spills wipe it with a wet paper towel, wear PPE What is true about mixing liquids in a separatory funnel? - correct answers...

Purification techniques (discussed so far) - correct answers Extraction Recrystallization Simple/fractional distillation Analysis techniques (discussed so far) - correct answers Mp NMR TLC When to use extraction - correct answers Want to separate compounds based on solubility and density gradient, and you have two immiscible liquids. Why could hexane be used in an extraction with water, but not acetone? - correct answers Acetone is water soluble and hexane isn't; extraction require...

Beer's Law Conditions - correct answers 1. Monochromatic Radiation is passed thru solution 2. Solution is not too concentrated. Typically <0.01M 3. Solution is homogenous 4. Absorbing species is not participating in a concentration dependent equilibirum X-Ray - correct answers Electronic Transitions - Core electrons UV-Vis - correct answers Electronic Transitions - Valence electrons; vibrational; rotational IR - correct answers Vibrational; Rotational Micro - correct answers R...

How do you extract the amine - correct answers 1. Dissolve in ether 2. add HCl to make amine soluble in water (not ether) 3. Extract aqueous layer 4. add NaOH 5. collect precipitate What layer will the amine be found in (ether/ aqueous) - correct answers aqueous Which layer is the aqueous layer - correct answers bottom which layer is the ether layer - correct answers top how can you tell which liquid will be which layer - correct answers density how do you extract the amine - ...

carrier gas - correct answers mobile phase gas in gas chromatography cold trapping - correct answers splitless gas chromatography injection technique in which solute is condensed far below its boiling point in narrow band at the start of the column electron capture detector - correct answers gas chromatography detector that is particularly sensitive to compounds with halogen atoms, nitro groups, and other groups with high electron affinity flame ionization detector - correct answers A g...

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...