CH 222 Lab Quiz Study Guide

TLC and when it should be used

Thin Layer chromatography is used to separate mixtures into different products

How to identify Separated spots on a TLC plate

Based on the color and polarity, the more polar molecules will be closer to the bottom

What compounds are in spinach

Carotenes(orange), Chlorophyll a & b(green or blue-green), xanthophylls(yellow)

Retention Factor Equation

Distance of spot/distance of solvent

What does IR measure?

Measures the vibrations of atoms

What info is obtained by IR

functional groups, number of functional groups, reduced mass, polarity

How does mass influence vibrations in IR?

Less vibrations, the higher the reduced mass the further to the right it is

How does bond order influence vibrations in IR?

The higher the bond order the smaller the vibrations

What is required after immediately shaking a separatory funnel?

Turn the nozzle to release gas

What makes a good extracting solvent?

Has very high solubility and is immiscible with the solvent

Why are there layer in extraction?

Due to density of the liquids

How do you take the melting point?

30C under and set temp to 10C over the melting point, when it starts melting to when it is fully a liquid is its melting point

Identify the purpose of a centrifuge

Separates materials, with the denser materials towards the bottom of the vial

Calculate the distribution coefficient in an extraction and what is a good value for it

Conc. of A in solvent/conc. of A in diff solvent,Above 1 is efficient

Count number of components in a mixture using GC

Wherever there is a bump

What properties influence the retention time in GC

1. Length of column 2. Temp. at which the column is maintained 3. Rate of flow of the carrier gas 4. The nature of the stationary liquid phase

Predict the correct order in GC

???

Calculate peak height of a substance in GC

Measure height in inches, find area by multiplying height by the width at half the height

Find major product in GC

whatever peak has the most area

Calculate percent of a substance in GC

Area of substance/area of all substances

Dehydration of an alcohol, what is the major and minor products

-OH is taken off, tertiary carbons with double bond is major, secondary with double bond is minor

Difference between dehydration of an alcohol with a polyatomic acid and with an acid halide

A double bond is formed with the polyatomic acid whereas an alkylhalide is formed with an acid halide

what is the purpose of anhydrous sodium sulfate?

drying agent, for removing traces of water from organic solutions

What does it mean to acid catalyze a reaction

Proton is donated from the acid to the organic reactant(substrate)

Name and ID common glassware used in the lab?

Test tube, beaker, pipet, Separatory funnel

What factors influence he rate of n SN2 reaction

1. Alkylhaide structure 2. Nature of leaving group 3. Properties of the nucleophile 4. Steric Hinderance