redox

Question 1

what are the oxidation numbers/states?

Answer 1

are the charge on the particle assuming all substances, compounds are made up of ions

Question 2

oxidation rules

Question 3

all elements have an oxidation state of?

Answer 3

0 - zero

Question 4

all group 1 elements have an oxidation state of..?

Answer 4

+1

Question 5

all group 2 elements have an oxidation state of..?

Answer 5

+2

Question 6

Al has a oxidation state of..?

Answer 6

+3

Question 7

F always have an oxidation state of …?

Answer 7

-1

Question 8

O oxygen always has an oxidation sate of..? except in …? and …?

Answer 8

• -2
• H2O2 = -1
• F2O = +2

Question 9

H has an oxidation sate of …? in all compounds except …? where it is..?

Answer 9

• +1
• metal hydrides = -1

Question 10

often but not always group 7 elements have an oxidation number of ..?

Answer 10

-1

Question 11

what is the key rule?

Answer 11

adding together all of the oxidation states equals the overall charge of the species

Question 12

for neutral compounds the sum of the oxidation sates equal ?

Answer 12

0 zero

Question 13

for -2 charged ions sum of the oxidation states equals?

Answer 13

-2

Question 14

for 1+ charged ions the sum of the oxidation numbers equal?

Answer 14

+1

Question 15

Redox

Question 16

what does oil rig stand for?

Answer 16

Oxidation
Is
Loss of electrons
Reduction
Is
Gain of electrons

Question 17

what examples of reactions are redox reactions?

Answer 17

• metal + non-metal –> ionic compounds
• non-metal + non-metal —> covalent compounds
• all displacement reactions
• all oxidation reactions including all combustion and oxidation of organic chemicals
• all reduction reactions including all extraction of all metals and reduction of organic compounds

Question 18

explain what is happening in the reaction below?
Mg (s) + 1/2 O2 (g) ——> MgO (s)

Answer 18

• magnesium has lost 2 electrons, so magnesium has been oxidised
• oxygen has gained 2 electrons, so oxygen has been reduced
• oxygen is the oxidising agent, magnesium is the reducing agent

Question 19

what are oxidising agents?

Answer 19

are electron acceptors so non-metals

Question 20

what are reducing agents?

Answer 20

are electron donors so metals

Question 21

redox reactions in acidic solutions

Question 22

some redox reactions will take place only in the presence of an …?

Answer 22

acid

Question 23

what do all acidic solutions contain?

Answer 23

H+ ions and water

Question 24

when balancing acidic redox equation what do we need to remember?

Answer 24

Water (WHE)
H+ ions
Electrons

Question 25

explain in steps?

Answer 25

1. write out the reactants on the left side and products on the right side of arrow 2. balance the oxygens by adding water 3. balance the hydrogens by adding H+ ions 4. Balance the charges by adding Electrons