1.7 Redox

Question 1

Define oxidation

Answer 1

The addition of oxygen, the loss of hydrogen, the loss of electrons

Question 2

Define reduction

Answer 2

The loss of oxidation, the gain of hydrogen, the gain of electrons

Question 3

What is an oxidation agent?

Answer 3

Oxidising agents are electron acceptors

Question 4

What is a reducing agent?

Answer 4

Reducing agents are electron donors

Question 5

What are the rules of oxidation numbers ?

Answer 5

1) the oxidation number of any element is zero
2) the oxidation of each of the atoms in a compound. Punts separately and their sum is 0
3) The oxidation of an element existing as a monatomic ion is the charge of the ion
4) in a polyatomic ion, the algebraic sum of the oxidation is the charge on the ion

Question 6

What elements have invariable oxidation numbers in their common compounds

Answer 6

Group 1 - 1+
Group 2 - 2+
Al - 3+
H - 1+
F - F-
Cl, Br, I - 1- (except in compounds with O and F)
O - O2- (except in peroxides and compounds with F)

Question 7

What are the rules for writing REDOX equations?

Answer 7

1) Write equations for the reduction and oxidation
2) add electrons to balance the change in oxidation number
3) balance for oxygen with water
4) balance for hydrogen with H+ ions
5) make sure the number of electrons in each equation is the same
6) add half equations together
7) cancel out any electrons and hydrogen ions