Redox

Question 1

What is oxidation?

in terms of oxygen, electrons and hydrogen

Answer 1

The gain of oxygen
The loss of electrons
The loss of hydrogen

Question 2

What is reduction?

in terms of oxygen, electrons and hydrogen

Answer 2

The loss of oxygen
The gain of electrons
The gain of hydrogen

Question 3

What is the oxidation state of an uncombined element?

Answer 3

Zero

Question 4

What is the sum of the oxidation states of all atoms or ions in a neutral compound?

Answer 4

Zero

Question 5

Which is given the negative oxidation state? The more electronegative element, or the less electronegative element?

Answer 5

The more electronegative element.

Question 6

What is the oxidation state of group 1 metals?

Answer 6

+1

Question 7

What is the oxidation state of group 2 metals?

Answer 7

+2

Question 8

What is the oxidation state of oxygen? Exceptions?

Answer 8

-2 (except in peroxides and F2O)

Question 9

What is the oxidation state of hydrogen? Exceptions?

Answer 9

+1 (except in metal hydrides where it is -1)

Question 10

What is the oxidation state of fluorine?

Answer 10

-1

Question 11

What is the oxidation state of chlorine?

Answer 11

-1 (except in compounds with O or F)

Question 12

What is a disproportionation reaction?

Answer 12

A species is both oxidised and reduced.

Question 13

What is the step by step process for writing out half equations?

Answer 13

1) Balance all species (ignore oxygen hydrogen)
2) Balance oxygen using H2O
3) Balance hydrogen using H+ ions
4) Balance charges using electrons (e-)

Question 14

How can half equations be combined?

Answer 14

Ensure the number of electrons are the same for both half equations. Multiply equation (like simultaneous equations).