Chemical tests

Question 1

test for alkenes

Answer 1

bromine water
orange –> colourless

Question 2

test with acidified potassium dichromate

Answer 2

K2Cr2O7
1 alcohol
2 alcohol
aldehyde
orange –> green

Question 3

test for aldehyde

Answer 3

tollens
-silver mirror

fehlings
-brick red precipitate

Question 4

test for carboxylic acid

Answer 4

-sodium carbonate
NaCO3
effervescence

Question 5

[Ba]2+ ion test

Answer 5

H2SO4
white ppt

Question 6

[SO4]2- ion test

Answer 6

BaCl2
white ppt

Question 7

[Mg]2+ ion test

Answer 7

NaOH
white ppt

Question 8

[OH]- ion test

Answer 8

MgCl2
white ppt

Question 9

Cl- ion test

Answer 9

AgNO3
white ppt

Question 10

Br- ion test

Answer 10

AgNO3
cream ppt

Question 11

I- ion test

Answer 11

AgNO3
yellow ppt

Question 12

AgCl ion test

Answer 12

Dilute NH3
AgCl ppt dissolves

Question 13

AgBr ion test

Answer 13

Conc. NH3
AgBr ppt dissolves

Question 14

[NH4]+ ion test

Answer 14

NaOH and heat
gas released turns
litmus paper
red –> blue

Question 15

[CO3]2-

Answer 15

Acid
Effervescence

Question 16

[Fe]2+

Answer 16

NaOH
green ppt –> brown
in air

Question 17

[Cu]2+

Answer 17

NaOH
blue ppt

Question 18

[Fe]3+

Answer 18

NaOH
brown ppt

Question 19

[Al]3+

Answer 19

NaOH
white ppt

OR

Excess NH3
white ppts dissolves to colourless solution