Topic 4- Extracting Metals/Equilibria

Question 1

Oxidation

Answer 1

Something is gaining oxygen

Question 2

Combustion

Answer 2

• Involves oxidation

- Exothermic

Question 3

Reactivity series

Answer 3

• Lists metals in order of their reactivity
• Carbon is listed in the reactivity series to show how easy it is for a metal to be extracted from its ore
• Hydrogen is included to show the reactivity of metals with dilute acids

Question 4

The Reactivity Series

Answer 4

• Potassium - Zinc
• Sodium - Iron
• Calcium - Hydrogen
• Magnesium - Jewellery metals
• Aluminium
• Carbon

Question 5

Placement of the reactivity series

Answer 5

• Metals at the top are the most resctive and they easily lose their cations. Also they are oxidised easily
• This is the opposite for metals at the bottom

Question 6

Reversible Reactions

Answer 6

• Can go forwards or backwards
• Products can revert to reactants
• The Haber Process is an example

Question 7

Equilibrium in reversible reactions

Answer 7

• As reactants react, their concentrations will fall
• But as concentrations of products rise, the backwards rate of reaction will increase
• After a while, they will reach the exact same rate
• There will be no overall effect
• This is called dynamic equilibrium as reactants and products have reached a balance
• This only takes place in a closed system

Question 8

Equilibrium on the right

Answer 8

• More products than reactants
• The concentration is greater on the right
• There is still no change

Question 9

Equilibrium on the left

Answer 9

• More reactants than products
• Higher concentration
• No overall change

Question 10

Factors that can effect the positioning of equilibrium

Answer 10

• Temperature
• Concentration
• Pressure

Question 11

Le Chatelier’s principle - temperature

Answer 11

• If you decrease the temperature, the equilibrium will move in the exothermic direction to produce more heat
• If you increase the temperature, the equilibrium will move in the endothermic direction to produce less heat

Question 12

Le Chatelier’s principle - Pressure

Answer 12

If you increase the pressure, the equilibrium will move towards the side that has fewer moles of gas to reduce pressure
If you decrease the pressure, the equilibrium will move to the side that has more moles of gas to increase pressure

Question 13

Le Chatelier’s principle - Concentration

Answer 13

• If you increase the concentration of the reactants, the equilibrium will move to the right to use up the reactants (making more products)
• If you increase the concentration of the products, the equilibrium will move to the left to use up the products (making more reactants)
• Decreasing will have a reverse effect