Identifications

Question 1

soluble in water/have 1 layer

Answer 1

1-4/5 (small) carbons

alcohols, amines, aldehydes, ketones, carboxlic acids, amides, and very small esters

Question 2

insoluble in water/make 2 layers

Answer 2

Carbons >= 5 (larger)

alcohols, amines, carboxylic acids, amides, esters

Question 3

insoluble in water/make 2 layers

Answer 3

All alkanes, alkenes, alkynes, haloalkanes

Question 4

turn moist red litmus blue

Answer 4

amine

Question 5

turn moist blue litmus red

Answer 5

carboxylic acid

Question 6

turn UI soln gree to blue/ moist UI paper blue

Answer 6

amine

Question 7

turn UI soln green to orange/ moist UI paper orange

Answer 7

carboxylic acid

Question 8

turn Cr2O72-/H+(aq) to Cr3+(aq),
orange to green when heated

Answer 8

1 alcohol, 2 alcohol, aldehyde

Question 9

turn Mno4-/H+(aq) to Mn2+(aq),
purple to colourless when heated

Answer 9

1 alcohol, 2 alcohol, aldehyde

Question 10

turn MnO4-/H+ to Mn2+,
purple to colourless soln
no heat needed

Answer 10

alkene(makes the diol)

Question 11

turn MnO4- to MnO2
purple soln to brown precipitate
no heat needed

Answer 11

alkene(makes the diol)

Question 12

react with NaHCO3 or Na2CO3 solid or soln(any salt containing carbonate ion)
producing colourless gas

Answer 12

carboxylic acid
gas is CO2

Question 13

react with Mg(any reactive metal)
producing colourless gas

Answer 13

carboxylic acid
gas is H2

Question 14

rotten, decomposing, fishy smell

Answer 14

amine

Question 15

sharp vinegary smell

Answer 15

carboxylic acid

Question 16

rapidly decolourise orange bromine water, Br2

Answer 16

alkenes and alkynes(unsaturated)

Question 17

slowly decolourise orange bromine water, Br2, needing UV light and/or heat

Answer 17

alkanes/other molecules with C-C bonds(saturated)

Question 18

often have pleasant fruity smell

Answer 18

esters

Question 19

react vigorously with water, making fumes of HCl;
remaining soln is acidic

Answer 19

acid chloride

Question 20

react with blue Cu2+(aq) to form deep blue soln of [Cu(RNH2)4]2+(aq)

Answer 20

amine

Question 21

create silver mirror(or black ppt) with Tollens’ reagent, [Ag(NH3)2]+ or Ag+/NH3

Answer 21

aldehyde

Question 22

Tollens’ reagent

Answer 22

solution of silver nitrate and ammonia, often with sodium hydroxide

Question 23

give red/orange ppt of Cu2O with Benedict’s or Fehling’s reagent/solution Cu2+

Answer 23

aldehyde

Question 24

Benedict’s reagent

Answer 24

mixture containing copper(II) sulfate, sodium citrate, and sodium carbonate

Question 25

Fehling's reagent

Answer 25

reagent is made by combining two separate solutions, Fehling's solution A and Fehling's solution B (CuSO4) soln A (NaOH) and sodium potassium tartrate soln B

Question 26

Fehling's vs Benedicts reagents

Answer 26

Benedict's reagent is a single solution containing copper(II) citrate, while Fehling's reagent consists of two separate solutions, A and B, containing copper(II) sulfate and sodium potassium tartrate/potassium hydroxide, respectively. Benedict's reagent is more stable and can be stored for longer periods, while Fehling's reagent is less stable and needs to be prepared fresh before use

Question 27

Able to rotate plane polarised light

Answer 27

molecule with chiral/asymmetric C atom

Question 28

soluble in water - one layer

Answer 28

polar molecule

Question 29

insoluble in water - two layers

Answer 29

non-polar molecule, or one with large non-polar region

Question 30

release NH3 gas if heated with NaOH NH3(g) turns red litmus blue

Answer 30

amide