4.9 Oxidation-reduction reaction

Question 1

how to recognise a redux reaction

Answer 1

The charges of the atoms must be different at the end than at the beginning

Question 2

what is the oxidation state of pure element Fe2, O2, Cl2

Answer 2

0

Question 3

what is the oxydation state of ions

Answer 3

their charge

Question 4

What is the oxydation state of H

Answer 4

when bonded to a non metal: 1
when bonded to a metal : -1

Question 5

What is the oxydation state of Fluorine when it‘s in a compound (F)

Answer 5

-1

Question 6

What is the oxydation state of oxygen when it‘s in a compound (O)
what is the exception

Answer 6

-2
exception:
H202 (peroxide) = -1

Question 7

What is the oxydation state of sodium and potassium when it‘s in a compound (alkali metals in general)

Answer 7

1

Question 8

oxydation state of chlorine

what are the exceptions

Answer 8

-1
Exception: when in compound with O and F

Question 9

What is the element that is being oxydised

Answer 9

• element that loses electrons (charge goes from smaller to bigger)
• it is called the reducing agent

Question 10

What is the element that is being reduced

Answer 10

• element that gains electrons (charge goes from bigger to smaller)
• also called the oxydizing agent

Question 11

In the half reaction method, what does it mean when electrons are on
- the right
- the left

Answer 11

right = oxydised
left = reduced

Question 12

how to know quickly if it is a redox reaction

Answer 12

• if a pure element becomes a compound
• general = when change in charge