Summer Colours

Question 1

Chlorine in water and organic solvent

Answer 1

Pale green

Question 2

Br2 in water and organic solvent

Answer 2

Orange

Question 3

I2 in water and organic solvent

Answer 3

Brown, Violet

Question 4

Cl- in silver halide and solubility

Answer 4

While precipitate, soluble in dilute NH3

Question 5

Br- silver halide and solubility

Answer 5

Cream precipitate, soluble in conc nh3

Question 6

I- silver halide and solubility

Answer 6

Yellow precipitate and insoluble in nh3

Question 7

Test for co32-

Answer 7

Dilute hno3 fizzing co2

Question 8

Test for so42-

Answer 8

Ba(no3)2
insoluble white precipitate of baso4

Question 9

Test for nh4+

Answer 9

Noah and heat nh3 turns litmus blue

Question 10

What species produce green and what are their charges and what is the oxidation number of the transition metal

Answer 10

. Fe2+ 2+ solution
. fe(oh)2 2+ (precipitate)
. Cr(oh)3 3+ grey-green precipitate
. [cr(oh)6]3- +3solution
. Cro42- 6+solution

Question 11

What species produce yellow and what is the oxidation number of the transition metal

Answer 11

. Fe3+ 3+ solution
. Fe(oh)3 3+ precipitAte
. [cucl4]2 2+ solution

Question 12

What species produce brown and what is the oxidation number of the transition metal

Answer 12

. Cu 0 brown solid
. Mn(oh)2 2+ light precipitate

Question 13

What species produce a colourless solution and what is the oxidation number of the transition metal

Answer 13

. Cu+ 1+ colourless

Question 14

What species produce a white solid and what is the oxidation number of the transition metal

Answer 14

. CuI +1 white solid

Question 15

What species produce a blue solution and what is the oxidation number of the transition metal

Answer 15

. Cu2+ 2+ solution
. [cu(nh3)4(h2o)2]2+ 2+ deep blue solution
. Cu(oh)2 2+ blue precipitate

Question 16

What species produce purple and what is the oxidation number of the transition metal

Answer 16

. Cr3+ 3+ violet solution
. [cr(nh3)6]3+ purple solution
. Mno4 - +7 purple solution

Question 17

What species produce an orange solution and what is the oxidation number of the transition metal

Answer 17

. Cr2o72- 6+ orange solution

Question 18

Wha species produce a pink solution and what is the oxidation number of the transition metal

Answer 18

. Mn2+ 2+ pale pink solution

Question 19

What is the chemical test for an alkene

Answer 19

. Br2
. Orange to colourless

Question 20

What is the chemical test for a haloalkane

Answer 20

. Agno3 in ethanol 50°c
. Same observations as cl br and I

Question 21

What is the chemical test for phenol

Answer 21

. Na2co3, br2
. No fizzing due to weak acidity
. Orange to colourless with white precipitate

Question 22

What is the chemical test for carbonyl aldehyde or ketone

Answer 22

. 2,4-dnph
. Orange precipitate

Question 23

What is the chemical test for aldehydes

Answer 23

. Tolkien’s reagent
. Silver mirror

Question 24

What is the chemical test for a 1 or 2 alcohol or aldehyde

Answer 24

. K2cr2o7 and h2so4 and heat
. Orange to green

Question 25

What is the chemical test for carboxylic acid

Answer 25

. Na2co3
. Fizzing