Organic Analysis Flashcards Preview

A Level chemistry year 1 > Organic Analysis > Flashcards

Flashcards in Organic Analysis Deck (10):
1

what reagent could you use to test a sample of alcohol to find out whether it was a tertiary secondary or primary alcohol?

acidified potassium dichromate
add 10 drops of alcohol warm and wait for colour change

primary - orange turns to green as aldehyde forms
secondary - orange turns to green as ketone forms
tertiary - nothing happens

2

describe how you can use benedict's solution to find out if a solution is an aldehyde or ketone

1. add 2cm3 of benedicts solution to test tube
2. add 5 drops of the aldehyde or ketone to the test tube
3. place in hot water bath for a few mins

aldehyde - blue solution gives brick red precipitate
ketone - nothing happens

3

which three solutions do you need to mix to create tollens reagent?

silver nitrate
dilute sodium hydroxide
dilute ammonia

4

describe how you would test a sample to find out weather it was a alkane or alkene

add solution to test tube
add bromine water to test tube and shake
alkenes - orange to colourless
alkanes - nothing happens

5

name the gas produced when a carboxylic acid reacts with sodium carbonate

carbon dioxide

6

in mass spectrometry, what is meant by a molecular ion?

a molecular ion is when a molecule looses an electron

7

explain how you could find the molecular mass of a compound by looking at its mass spectrum

if the value of the m/z value is 72 so must be the Mr
if you calculate the Mr for the first few straight chain alkanes you will find that it is pentane

8

which parts of a molecule absorb infrared radiation?

covalent bonds

9

on an infrared spectrum, what is meant by the fingerprint region?

the region between 500 and 1500 cm-1

10

explain how increasing the amount of carbon dioxide in the atmosphere leads to global warming

electromagnetic radiation absorbed by the sun id emitted as IF radiation

greenhouse gasses absorb the IF radiation then reemit it back to the earth . green house effect

heat is being trapped in the earth so it is getting hotter
global warming