Ch 10 - (Redox Reactions)

Question 1

What is a redox reaction?

Answer 1

When oxidation and reduction take place together at the same time.

Question 2

What is oxidation?

Answer 2

Gain of oxygen (when O2 is added)

Question 3

What is reduction?

Answer 3

Loss of oxygen (when O2 is removed)

Question 4

What does the roman numeral written after the number refer to?

Answer 4

The oxidation number of an element.

Question 5

What can redox reaction also be defined as?

Answer 5

Electron transfer

Question 6

Define oxidation.

Answer 6

Oxidation is the reaction in which an elements, ion, or compound loses electrons

Question 7

What happens to the oxidation number due to oxidation?

Answer 7

• Oxidation number increases.
• Shown in half equation

Ag –> Ag+ + e-

Question 8

Define reduction.

Answer 8

Reduction is the reaction in which an element, ion, or compound gains electrons

Question 9

What happens to the oxidation number due to reduction?

Answer 9

• Oxidation number is decreased
• Half equation

O2 + 4e –> 202-

Question 10

Why are spectator ions?

Answer 10

That do not change or take part in the reaction.

Question 11

What is OIL RIG?

Answer 11

O - Oxidation
I - is
L - Loss of electrons

R - Reduction
I - is
G - gain of electrons

Question 12

What is oxidation number?

Answer 12

A number assigned to an atom or ion in a compound which indicates the degree of oxidation (reduction)

Question 13

What does oxidation number show?

Answer 13

It shows the number of electrons that an atom has lost, gained, or shared in forming a compound.

Question 14

What does the oxidation number help keep track of?

Answer 14

It helps you keep track of the movement if electrons in a redox process.

Question 15

How is oxidation number written as?

Answer 15

+/- sign followed by a number ( not to be confused with a charge which is written by a number followed by + / - )

Question 16

When can redox reaction be identified?

Answer 16

The changes in oxidation number when a reactant goes to a product.

Question 17

How can we test for redox reactions?

Answer 17

Involve the observation of a color change.

Question 18

Hats re two examples of identifying color change in redox reactions?

Answer 18

• Acidified potassium manganate (VII)
• Potassium iodide
• Potassium manganate (VII), KMnO4 is an oxidising agent which tests for the presence of reducing agents.

Question 19

What happens when acidified potassium manganate (VII) is added to a reducing ageng?

Answer 19

Color changes from purple to colorless

Question 20

What is potassium iodide? KI?

Answer 20

A reducing agent which is often used to test for the presence of oxidising agents.

Question 21

What happens when acidified solution of an oxidising agent such as aqueous chlorine or hydrogen peroxide (H2O2)

Answer 21

• turns red brown due to the formation of I2
• Potassium iodide is oxidised as it loses electron and peroxide is reduced, therefore potassium iodide is a reducing agent.

Question 22

What is an oxidising agent?

Answer 22

A substance that oxidises another substance, and becomes reduced in the process.

Question 23

What happens in an oxidising agent?

Answer 23

An oxidising agent agent gains electrons as another substance loses electrons

Question 24

What is an example of an oxidising agent?

Answer 24

Hydrogen peroxide, fluorine and chlorine

Question 25

Define a reducing agent.

Answer 25

A substance that reduces another substance, and becomes oxidised in the process.

Question 26

What happens in a reducing agent?

Answer 26

Loses electrons as another substance gains electrons.

Question 27

What’s are examples of reducing agents?

Answer 27

Carbon and oxygen.

Question 28

Why is reduction very important in chemical industry?

Answer 28

To extract metal from metal ores.