paper 2

Question 1

test for aldehydes and ketones and results

Answer 1

tollens reagent
- aldehyde: silver mirror
-ketone: no observation

or fehlings solution
aldehyde: orange/red precipitate
ketone: no observation

Question 2

whats the meaning of fractions in fractional distillation

Answer 2

a mixture of compounds with similar boiling points

Question 3

whats the catalyst used for catalytic cracking

Answer 3

zeolites

Question 4

test for alkenes and alkanes and results

Answer 4

bromine water

-alkene: turns colourless
-alkanes: no observation

Question 5

why does carbon dioxide absorb infrared radiation

Answer 5

the C=O bond vibrates at the frequency of IR radiation

Question 6

what environmental problem does NO cause

Answer 6

acids rain

Question 7

why may experimental and theoretical enthalpies differ

Answer 7

the value measured may not be accurate due to heat loss or incomplete combustion

Question 9

What’s is a reflux reaction

Answer 9

heating the chemical reaction while continually cooling the vapour produced back into liquid form, using a condenser