Colours Of Tm

Question 1

What oxidises fe2+ to fe3+

Answer 1

Acidified KMNO4

Question 2

What is the colour change from fe2+ to fe3+

Answer 2

Pale green to yellow

Question 3

What reduces fe3+ to fe2+

Answer 3

Iodine ions

Question 4

What is the colour change from fe3+ to fe2+

Answer 4

Yellow to pale green

Question 5

What does cr3+ get oxidised into

Answer 5

CrO4 2-

Question 6

What oxidises cr3+ to crO4 2-

Answer 6

H2O2

Alkaline conditions

Question 7

What does crO4 2- with acid produce

Answer 7

Cr2O7 2-

Question 8

What colour change happens with the oxidation of cr3+ to crO4 2-

Answer 8

Dark green to yellow

Question 9

What is the colour change from crO4 2- to cr2o7 2-

Answer 9

Yellow to orange

Question 10

How is cr2o7 2- reduced to cr3+

Answer 10

Acidified Zn

Question 11

What is Cr2O7 2- reduced into with Zn

Answer 11

Cr 3+

Question 12

What is the colour change with cr2o7 2- to cr3+

Answer 12

Orange to green

Question 13

How is cu2+ reduced into Cu+

Answer 13

Iodide ions

Question 14

What is cu2+ reduced to in the presence of I-

Answer 14

Cu+

Question 15

What is the colour change with cu2+ to Cu+

Answer 15

Pale blue to off white precipitate

Question 16

What is the equation for Cu+ spontaneously disproportionating

Answer 16

2cu+ -> Cu + cu2+

Question 17

What happens when cu(oh)2 reacts further with excess nh3

Answer 17

[cu(nh3)4(h2o)2]2+

Pale blue ppt > dark blue sol

Question 18

What is the colour of [cr(h2o)6]3+

Chemically and realistically

Answer 18

Chemically = violet

Actually looks= green

Question 19

What is the colour of [cr(oh)3]

Answer 19

Grey green ppt

Question 20

What happens with [cr(h2o)]3+ in excess naoh

Answer 20

Forms cr(oh)6]3-

Grey green ppt -> Dark green solution

Question 21

What happens with [cr(h2o)]3+ in excess nh3

Answer 21

Forms cr(nh3)6]3+

Grey green ppt -> purple