Module 6

Question 1

Qualatative test for carbonyl c=o

Answer 1

Add 2,4-DNP. Positive test= deep orange/red precipitate.

Question 2

Test for aldehyde from a carbonyl

Answer 2

Trollers reagent - add to warm sample and leave for 5 mins. Aldehyde forms silver mirror

Question 3

Acyl chloride production equation

Answer 3

CH3COOH + SOCl2>CH3COCl+SO2+HCl

Question 4

solid purification

Answer 4

Recrystalisation: dissolvedve in min volume of hot suitablele solvent. cool then vaccum filter.wash with distilled.

Question 5

Liquid purification

Answer 5

Separating funnel. Neutralisation N2CO3, remove bottom layer. Wash with distilled water+remove bottom layer. Dry with drying agent MgCl2

Question 6

Halo alkane test

Answer 6

React with AgNO3 (aq), test precipitate with NH3 (aq).
AgCl- white precipitate, soluble in dilute NH3
AgBr- cream precipitate, soluble in concentrated NH3
AgI - yellow precipitate, insoluble in NH3
Reactivity increases down group ( I is most reactive Cl is least)

Question 7

Carboxylic acid test

Answer 7

pH less than 7 and effervescence when reacted with carbonate as CO2 is released.

Question 8

Primary and secondary alcohol and aldehyde

Answer 8

Add acidified potassium dichromate in water bath, colour change from orange to green

Question 9

Carbonate test CO3 ^2-

Answer 9

Add dilute nitric acid to the test subject, bubbles will form, bubble the gas through lime water and it will turn cloudy.

Question 10

Sulfate ion test SO4 ^2-

Answer 10

Add aqueous barium ions and white precipitate will form

Question 11

Order of anion gets

Answer 11

Carbonate,sulfate,halide