Physical: Redox Reactions

Question 1

What is an oxidising agent?

Answer 1

a substance that removes electrons from another species

an electron receiver

Question 2

What is a reducing agent?

Answer 2

a substance that adds electrons to a species

Question 3

What is a redox reaction?

Answer 3

a reduction-oxidation reaction

electrons are transferred from one species to another

Question 4

What is an oxidation state?

Answer 4

it tells you how many electrons you have lost or gained

Question 5

What is the oxidation state in elements?

Answer 5

0

Question 6

What does the oxidation state of elements in a compound sum to?

Answer 6

0

Question 7

For complex ions, what does the sum of the oxidation states sum to?

Answer 7

the charge on the ion

Question 8

What is the oxidation state for hydrogen?

Answer 8

+1

except in metal hydrides, then it is -1

Question 9

What is the oxidation state of Al?

Answer 9

+3

Question 10

What is the oxidation state of oxygen?

Answer 10

-2 in compounds except in peroxides when it is -1

Question 11

What is the oxidation state of fluorine?

Answer 11

-1

Question 12

What is the oxidation state of chlorine?

Answer 12

-1

except when it is in a compound with oxygen or fluorine - then it has a positive value

Question 13

How can you use oxidation states to determine whether there is a redox reaction?

Answer 13

if there is an increase in oxidation state in a species, oxidised
if there is a decrease in oxidation state in a species, reduction occurs
if both happen in the same reaction, then it is redox