Elements from the sea(ES)

Question 1

What factors can affect the position of equilibrium?

Answer 1

Concentration, pressure and temperature

Question 1

What is meant by ‘dynamic equilibrium’

Answer 1

A reversible reaction which takes place in a closed system. The rate of the foward reaction is equal to the rate of the backwards reaction. Concentrations remain constant

Question 2

What happens to the position of eqm if temperature:
-Increases
-decreases

Answer 2

-Increases=direction of the endothermic reaction
-Decreases=direction of the exothermic reaction

Question 3

What happens to the position of eqm if the pressure
-Increases
-Decreases

Answer 3

-Increases=Side with fewer gas molecules
-Decreases=Side with more gas molecules

Question 4

Why don’t catalysts affect the position of eqm?

Answer 4

Catalysts only increase the rate of the foward and backward equation equally. Therefore they don’t affect the position of eqm

Question 5

What is the other name for group 7 elemants?

Answer 5

Halogens

Question 6

What bond is formed between two group 7 elements?

Answer 6

Covalent

Question 7

What is the appearance of Fluorine,Chlorine, Iodine and bromine at room temperature?

Answer 7

• Fluorine~pale yellow gas
• Chlorine~green gas
• Bromine~dark red volatile liquid
• Iodine~shiny black solid

Question 8

What happens as you go down group 7?

Answer 8

• Becomes darker in colour
• Melting and boiling points increase
• Become less volatile

Question 9

Are halogens more soluble in water or organic solvents e.g. hexane

Answer 9

Orgainc solvents~this means that in organic solvents halogens have a much more distinct colour

Question 10

Size of the atom

Why is fluorine a stronger oxidisng agent than chlorine?

Answer 10

• F atoms are smaller=attraction between nucleus and outer electron is very strong
• This attraction is weaker in Cl
• This means that F gains an extra electron more readily to become a negative ion than Cl

Question 11

What is the reaction between a halogen and a halide?

Answer 11

Displacement reaction

Question 12

Why does a displacement reaction happen?

Answer 12

A halogen displaces a less reactive halogen from the compound

Question 13

What is the test for halide ions?

Answer 13

Add silver nitrate solution then ammonia to distinguish between the halides

Question 14

What is precipitate of chloride,bromide and iodide when silver nitrate is added?

Answer 14

• Chlorine~White
• Bromine~Cream
• Iodine~Pale yellow

Question 15

What is the result of cyclohexane with chlorine,bromine and iodine?

Answer 15

• Chlorine~TL pale green and BL colourless
• Bromine~TL orange and BL pale orange
• Iodine~TL violet and BL brown

Question 16

What is the results of potassium bromide with chlorine,bromine and iodine?

Answer 16

• Chlorine~pale yellow
• Bromine and iodine~no reaction

Question 17

What is the results of potassium iodide with chlroine,bromine and iodine?

Answer 17

• Chlorine and bromine~TL violet and BL pale brown
• Iodine~No reaction

Question 18

What can a redox reaction be defined by?

Answer 18

• Electrons
• Oxidation state
• Oxygen

Question 19

What happens if an ionic compound is melted or dissolved?

Answer 19

Charged ions are free to move around and carry a current

Question 20

What is produced at the cathode?

Answer 20

Metal

Question 21

What is produced at the anode?

Answer 21

Non-metal, apart from hydrogen