Redox

Question 1

oxidation number of an atom in elemental state?

Answer 1

0

Question 2

oxidation number of group 1 metals?

Answer 2

+1

Question 3

oxidation number of group 2 metals?

Answer 3

+2

Question 4

oxidation number of group 13 elements?

Answer 4

+3

Question 5

oxidation number of fluorine?

Answer 5

-1

Question 6

oxidation number of hydrogen?

Answer 6

• mostly +1
• -1 in metal hydrides

Question 7

oxidation number of oxygen?

Answer 7

• mostly -2
• -1 in peroxides
• +2 in OF2, oxygen difluoride

Question 8

what is oxidation?

Answer 8

• gain in oxygen
• loss in hydrogen
• gain in oxidation number
• loss in electrons

Question 9

what is reduction?

Answer 9

• loss in oxygen
• gain in hydrogen
• loss in oxidation number
• gain in electrons

Question 10

definition of a redox reaction?

Answer 10

electron transfer reactions where both oxidation and reduction occurs simultaneously

Question 11

what is a disproportionation reaction?

Answer 11

a redox reaction where a single substance undergoes oxidation and reduction simultaneously

Question 12

what is an oxidizing agent?

Answer 12

a substance that oxidizes other substances but undergoes reduction itself

Question 13

what is a reducing agent?

Answer 13

a substance that reduces other substances but undergoes oxidation itself

Question 14

examples of oxidizing agents and their color change?

Answer 14

1. acidified potassium manganate (KMnO4), purple to colorless
2. acidified potassium dichromate (K2Cr2O7), orange to green
3. hydrogen peroxide (H2O2), no color change

Question 15

examples of reducing agents and their color change?

Answer 15

1. potassium iodide (KI), colorless to brown
2. hydrogen peroxide (H2O2), no color change