Elements Of The sea

Question 1

What are the group 7 elements

Answer 1

Halogens

Question 2

As you go down the group, what happens to the thermal stability, physical appearance, states, reactivity, volatility, mp/bp

Answer 2

Thermal stability decreases
Becomes darker in colour
Gases to liquids to solids
Reactivity decreases
Becomes less volatile 
Mp/bp increases

Question 3

What is a reducing agent

Answer 3

It’s been oxidised and it reduces another ion

Question 4

What are spectator ions?

Answer 4

Ions that don’t change in a reaction

Question 5

What is a displacement reaction?

What displaces each other in group 7?

Answer 5

When an atom pushes out another atom and takes its place
Chlorine displaces bromine and iodine
Bromine displaces iodine

Question 6

What are the colours formed when halogens react with silver to form silver halides?
+ when ammonium solution is added?

Answer 6

Chlorine - White
Bromine - Cream
Iodine - Pale yellow

Chlorine - clear
Bromine - cloudy/bit clear
Iodine - insoluble

Question 7

O I L R I G?

Answer 7

Oxidation Is Loss Reduction Is Gain

Question 8

What are oxidation states useful for?

Answer 8

• Naming inorganic compounds
• Deciding what has been oxidised and what has been reduced
• identifying the oxidising agents and reducing agents
• balancing redox reactions

Question 9

What is the oxidation states for :

• Element
• Simple ion
• Compound
• Complex compound

Answer 9

• 0
• the charge on the ion
• charges add to 0
• charges add to charge on the compound

Question 10

What is electrolysis?

Answer 10

When electricity is passes through a molten or aqueous ionic compound, the compound is broken down and the process is called electrolysis

Question 11

What Is reduced at the cathode when there’s a group 1/2 metals present?

Answer 11

Hydrogen

2H2O + 2e —> 2OH- + H2

(If other metals then the metal is reduced.)
(Hydrogen if acid)

Question 12

What is oxidised at the anode if the salt is a halide?

Answer 12

Halogen

Oxygen if sulfate or nitrate
(Oxygen is alkali)

Question 13

Kc - constant

What is the equation?

Answer 13

[A]a [B]b

Products
___________
Reactants

Question 14

Risks of chlorine?

Answer 14

Toxic gas
Irritant to eyes, skin, respiratory system
Reacts with lungs to for, HCl which effects the tissues

Question 15

How is chlorine transported?

Answer 15

Uses pressurised tank containers
In liquid to store more
If pressure or temp too high, the tanks has pressure release devices to vent the tank and releases Cl as a gas
The tank if made and lined with steel
Dry so doesn't react with anything

Question 16

Uses of chlorine

Answer 16

Water treatment
Household bleach
Remove stains on clothing

Question 17

What is atom economy and what is the equation?

Answer 17

It’s the percentage of reactants that end up in the desired products

Atom economy = Mr of desired product / Mr of reactants x 100

Question 18

How do u make hydrogen halides?

Answer 18

HCl = sodium chloride + sulfuric acid as it's not a strong enough reducing agent
HBr = sodium bromide + phosphoric acid as its a strong enough reducing agent to reduce sulfuric acid to sulfur dioxide 
HI = sodium iodide + phosphoric acid as it reduces sulfur dioxide to hydrogen sulfide

Question 19

What happens if:
Pressure increases
Temperature increases
Temperature decreases
Pressure decreases

Answer 19

Side with fewer gas moles
Endothermic direction
Exothermic direction
Side with more gas moles

Question 20

If concentrations of :
Reactants increase
Reactants decrease
Products increases
Products decrease

Answer 20

The equilibrium moves to the 
Products side
Reactants side
Reactants side
Products side

Question 21

What is the trend in thermal stability and acidity as you go down the group?

Answer 21

Thermal stability decreases

HCl HBr HI are very acidic

Question 22

What is the reaction with halogens and ammonia?

Answer 22

Glass rid dipped in ammonia solution and put it near halogen and a white cloud of ammonium halide is made.