Organic Analysis

Question 1

Test for aldehyde

Answer 1

Tollens reagent
Positive test silver mirror

Fehlings solution
Positive test: blue solution to red precipitate

Question 2

Test for carboxylic acid

Answer 2

React solution with carbonate
Makes CO2 (fizz)
When bubbles through limewater turns cloudy

Question 3

Test for alkenes

Answer 3

Add bromine water

Orange to colourless

Question 4

Tests for alcohols

Answer 4

Acidified potassium dichromate

Orange to green if primary or secondary alcohol is present

Question 5

When is high resolution mass spec useful

Answer 5

When identifying different molecules with the same molecular mass rounded to the nearest whole number

Question 6

How does infrared spectroscopy work

Answer 6

Increases vibrational energy of covalent bond of structure

Question 7

Why is the fingerprint region useful

Answer 7

Allows us to identify specific molecules

Question 8

How do you make tollens reagent

Answer 8

1. Silver nitrate
2. then add sodium hydroxide
3. then add ammonia

Question 9

What are the three greenhouse gases

Answer 9

Water vapour
Carbon dioxide
Methane

Question 10

How does global warming happen

Answer 10

• Electromagnetic radiation from the sun comes to the earth and is either absorved or re emitted as infrared
• Greenhouse gases absorb the raditation and remit this back to the earth (this warms the earth up)
• However an increase in human activity leading to the increase in greenhouse gases means that more heat is remitted back to the eart