105) Magnesium produces small bubbles of gas when placed in water; it reacts rapidly with steam and acid. Lithium fizzes on the surface of water. Which is more reactive?
Answer 33106) What is a displacement reaction?
Answer 106107) In metal displacement reactions, is the reactive metal oxidised or reduced?
Answer 107108) Where are most metals obtained from?
Answer 108109) Name a metal that is not extracted from an ore and explain why.
Answer 109110) When metals are extracted are ores oxidised or reduced?
Answer 110111)Describe how iron is extracted from its ore.
Answer 111112) Describe how aluminium is extracted from its ore.
Answer 112113) Explain why aluminium is extracted in this way, and not by simply heating it with carbon.
Answer 113Aluminium is a reactive metal.
Reactive metals bond strongly to the other elements in their ores. It requires a lot of energy to break these chemical bonds. Electrolysis can provide large amounts of electrical energy to separate the metal from the other elements in the ore.
All reactive metals have to be extracted by electrolysis. The disadvantage is that this method is expensive.
114) Why is iron not extracted from its ore using electrolysis?
Answer 114115) How does the phyto extraction of copper work?
Answer 115116) What is bioleaching?
Answer 116117) Would you expect a metal low down the reactivity series to be susceptible to oxidation?
Answer 117118) Why do we recycle scrap metal?
Answer 118- It can often be cheaper to recycle rather than extract new metal from its ore.
- Recycling cuts waste which could otherwise harm the environment.
- Preserves the remaining raw materials on the planet.
119) What does a lifetime assessment of a product involve?
Answer 33Evaluating the effect on the environment of:
- Manufacturing
- Using
- Disposing
120) What does this symbol mean? ⇌
Answer 120121) What is meant by the term ‘dynamic equilibrium’?
Answer 121122) How can you change the equilibrium of a reversible reaction?
Answer 122123) What is the equation for the Haber process?
Answer 123124) Where are the reactants obtained from in the Haber process?
Answer 124125) What is the chemical formula for ammonia?
Answer 125126) What are the conditions used in the Haber process?
Answer 126- temperature 450 °C
- pressure 200 atmospheres
- iron catalyst
127) How does increasing the temperature affect the yield of ammonia?
Answer 127128) If increasing the temperature reduces the yield of ammonia why is a temperature of 450 oC used?
Answer 128129) How does increasing the pressure affect the yield of ammonia?
Answer 129130) How does adding a catalyst affect the yield of ammonia?
Answer 130131) How would the position of a dynamic equilibrium be affected by?
- temperature?
- pressure?
- concentration?
- Increasing the temperature will move the dynamic equilibrium in the direction of the endothermic reaction.
- Increasing the pressure will move the dynamic equilibrium towards the side where there are less gas molecules.
- Increasing the centration of a substance will move the equilibrium to reduce the concentration of that substance.