Elements of Sea

Question 1

Where do negative ions (anions) move to during electrolysis?

Answer 1

the postive electrode (anode) lose electrons

Question 2

Where do positive ions (cations) move to during electrolysis>

Answer 2

the negative electrode (cathode) gain electrons

Question 3

At the cathode, if the metal is less reactive than hydrogen, What will be formed?

Answer 3

the metal

Question 4

If the metal is more reactive than hydrogen at the cathode what will form>

Answer 4

hydrogen gas

Question 5

What is formed at the anode when a concentrated halide solution is electrolysed?

Answer 5

the halogen gas

Question 6

Explain what determines the product formed at the cathode when you electrolyse an aqueous solution,

Answer 6

If the metal ion is more reactive than hydrogen, hydrogen is formed.

If the metal ion is less reactive than hydrogen, the metal is formed

Question 7

What two halogens does chlorine displace during electrolysis?

Answer 7

bromine and iodine

Question 8

what would the oxidation state of a Mg2+ ion be?

Answer 8

+2

Question 9

What oxidation state is hydrogen nearly always?

Answer 9

+1

Question 10

if an atom loses one electron what happens to the oxidation state?

Answer 10

it increases by 1

Question 11

in a redox reaction. Is the oxidising agent oxidised or reduced?

Answer 11

reduced

Question 12

what do iodine-sodium thiosulfate titrations find?

Answer 12

the concentration of an oxidising agent.

Question 13

what is the trend in reactivity of the halogens as you go down the group?

Answer 13

reactivity decreases.

Question 14

Cl2 + 2KBr —–> ?????

Answer 14

——> 2KCl + Br2

the chlorine has displaced the less reactive halide ions in the solution

Question 15

What colour is chlorine in water?

Answer 15

colourless

Question 16

what colour is bromine in water?

Answer 16

yellow/orange

Question 17

what colour is iodine in water?

Answer 17

brown

Question 18

what colour is iodine in hexane

Answer 18

pink

Question 19

what colour is bromine in hexane

Answer 19

orange/red

Question 20

what colour is chlorine in hexane

Answer 20

colourless

Question 21

What is the appearance of flourine at RTP?

Answer 21

pale yellow gas

Question 22

What is the appearance of chlorine at RTP?

Answer 22

yellow-green gas

Question 23

What is the appearance of bromine at RTP?

Answer 23

red-brown liquid

Question 24

What is the appearance of iodine at RTP?

Answer 24

shiny grey solid

Question 25

Why do halogens have low solubility in water.

Answer 25

because they are covalent and non polar

Question 26

If you are identifying a halide in a solution by adding silver nitrate and a cream precipitate is formed. What is the halide present?

Answer 26

Bromine

Question 27

If you are identifying a halide in a solution by adding silver nitrate and a white precipitate is formed. What is the halide present?

Answer 27

chloride

Question 28

If you are identifying a halide in a solution by adding silver nitrate and a yellow precipitate is formed. What is the halide present?

Answer 28

Iodide

Question 29

If you are identifying a halide in a solution by adding silver nitrate and no precipitate is formed. What is the halide present?

Answer 29

fluoride

Question 30

if you increase temperature what way will the equilibrium shift?

Answer 30

endothermic direction

Question 31

if you increase the pressure of a reaction what way will the equilibrium shift?

Answer 31

to the side with fewer gas molecules