168-203 (joel)

Question 1

What do the ions discharged when an aqueous solution is electrolysed using inert electrodes depend on ?

Answer 1

The relative reactivity of elements involved

Question 2

What is the water in the solution broken down during electrolysis broken into ?

Answer 2

Hydrogen ions
Hydroxide ions

Question 3

What is produced at the cathode

Answer 3

Hydrogen is produced if the metal is more reactive than hydrogen

Question 4

What is produced at the anode ?

Answer 4

Oxygen is produced unless the solution contains a halide then the halogen is produced

Question 5

In the electrolysis of salt solution (brine) what is produced (3)

Answer 5

Hydrogen is produced at the cathode,chlorine is produced at the anode and sodium hydroxide is the solution

Question 6

During electrolysis what happens to positively charged ions

Answer 6

They gain electron(s) this is reduction

Question 7

Reactions at the electrodes can be represented as?

Answer 7

Half equations

Question 8

During electrolysis what happens to the negatively charged ions

Answer 8

They lose electrons this is known as oxidation

Question 9

What is an exothermic reaction (2)

Answer 9

One that transfers the energy to the surroundings so the temperature of the surroundings increases

Question 10

What happens to energy in chemical reactions

Answer 10

It is conserved

Question 11

What are some examples of exothermic reactions (3)

Answer 11

Combustion many oxidation reactions and neutralisation

Question 12

What are everyday uses of exothermic reactions (2)

Answer 12

Slef heating cans and hand warmers

Question 13

What is an endothermic reaction (2)

Answer 13

One that takes energy in form the surroundings so the temperature of surroundings decreases

Question 14

Endothermic Reactions include (2)

Answer 14

Thermal decomposition, and the reaction if Citric acid and sodium hydroxide

Question 15

What’s an everyday use of an endothermic reaction

Answer 15

Sports injury pack

Question 16

What is the activation energy

Answer 16

The energy needed for a reaction to occur

Question 17

On a reaction profile the activation of energy is shown as

Answer 17

The distance from the energy of the reactants to the top of the curved line

Question 18

On a reaction profile if the reactants have more energy than the products what type of reaction is it

Answer 18

Exothermic more as energy had been released

Question 19

On a reaction profile if the products energy than the reactants what type of reaction had taken place

Answer 19

Endothermic energy has been taken in

Question 20

To break bonds what is needed

Answer 20

Energy

Question 21

What is released as bonds are made

Answer 21

Energy

Question 22

In an exothermic reaction the energy released from forming new bonds is greater or less than the energy needed to break existing bonds

Answer 22

Greater

Question 23

What is electrolysis

Answer 23

The break down of a substance using electricity

Question 24

What can metals be extracted form using electrolysis

Answer 24

Molten compounds

Question 25

The ions in ionic compounds are free to move when they are melted or dissolved so can do what

Answer 25

Conduct electricity

Question 26

What are electrolysis

Answer 26

Liquids and solutions that can conduct electricity

Question 27

What happens when electricity Is passed through an electrolyte

Answer 27

Positive ions move to the negative electrode(cathode) and negative ions move to the positive electrode(anode)

Question 28

What is the positive electrode called

Answer 28

Anode

Question 29

What is negative electrode called

Answer 29

The cathode

Question 30

Ions are discharged at the electrode to produce

Answer 30

Elements

Question 31

Metal ions are attracted to what and what is produced

Answer 31

The cathode A metal is produced

Question 32

What electrodes are used when extracting a metal from it’s compound

Answer 32

Inert(unreactive)

Question 33

What are large amounts of used for in electrolysis to melt compounds and produce the electrical current

Answer 33

Energy

Question 34

What is aluminium oxide mixed with to lower it’s melting point

Answer 34

Cryolite

Question 35

Why does the anode need to be replaced regularly

Answer 35

Because it is made out of graphite a form of carbon that reacts with oxygen to form carbon dioxide