redox

Question 1

What is the oxidation number of hydrogen in metal hydrides e.g. LiH?

Answer 1

-1

Question 2

What is the oxidation number of a metal

Answer 2

0 because it is an uncombined element

Question 3

What is hydrated salt?

Answer 3

A hydrated salt contains water of crystallisation

Question 4

What are oxyanions?

Answer 4

Negative ions that have an element along with oxygen

Question 5

Define oxidation in terms of electron transfer and oxidation number

Answer 5

Oxidation is:

• Loss of electrons
• Increase in oxidation number

Question 6

What is the oxidation number of combined hydrogen?

Answer 6

+1

Question 7

What is a redox reaction

Answer 7

A reaction in which both oxidation and reduction take place

Question 8

What is the oxidation number of oxygen in peroxides e.g: Na2O2?

Answer 8

-1

Question 9

What is the oxidation number of combined oxygen?

Answer 9

-2

Question 10

How do hydrated salts lose their water of crystallisation?

Answer 10

Hydrated salts lose their water of crystallisation when heated, to become anhydrous.

Question 11

What is the oxidation number of an uncombined element such as: C, H, O2?

Answer 11

0

Question 12

What is the oxidation number of a simple ion?

Answer 12

Same as charge on the ion

Question 13

Define reduction in terms of electron transfer and oxidation number

Answer 13

Reduction is:

• Gain of electrons
• Decrease in oxidation number

Question 14

What is the oxidation number of Fe in iron (III) chloride

Answer 14

3+

Question 15

What is the oxidation number of combined fluorine such as in NaF?

Answer 15

-1

Question 16

What is water of crystallisation?

Answer 16

The water in a lattice (crystals of the compound contain water molecules bonded into the crystal structure).

Question 17

What is an oxidation number?

Answer 17

The number of electrons an atom uses to bond with any other atom

Question 18

When an element has more than 1 stable oxidation number how is it indicated?

Answer 18

Written as a Roman Numeral