Extracting metals and equilibria C4

Displacement reactions

Displacement reactions

• a type of redox reduction (reduction/oxidation)

• more reactive element displaces a less reactive element from a compound in terms of electrons

oxidisation

• gain of oxygen

• loss of electrons

reduction

• loss of oxygen

• gain of electrons

extraction of metals includes

reduction of ores

extraction of ores in relation to position on the reactivity scale

• Metals Below Carbon in the Reactivity Series (e.g., iron) can be extracted by heating with carbon, which is a cost-effective method.

• Metals Above Carbon in the Reactivity Series (e.g., aluminium) require electrolysis, which is more expensive due to the high energy demands.

extraction of ores biological methods

Bioleaching uses bacteria to extract metals from low-grade ores, making it cost-effective and environmentally friendly, but slower than traditional methods.

Phytoextraction involves plants absorbing metals from the soil, which is sustainable and good for land restoration, but it’s slow and yields less metal.

Life Cycle Assessment

• Raw Materials: Assessing the environmental effects of obtaining and processing the raw materials.

• Manufacturing: Evaluating the impact of producing the product, including energy use and waste.

• Use: Considering the environmental effects during the product’s usage, such as energy consumption and emissions.

• Disposal: Examining the impact of disposing of the product, including recycling, landfill, or incineration.

Reversible reactions

• reversible reactions can go both ways ⇌

• changing conditions can shift the direction of the reaction

• e.g A+B⇌C+D

Dynamic equallibrium

• Dynamic equilibrium occurs in a reversible reaction when the rates of the forward and reverse reactions are equal

• The reaction appears to stop, but both forward and reverse reactions continue at equal rates.

Formation of ammonia

• sources: nitrogen form air, hydrogen from natural gas

• dynamic equilibrium: rates of forward and reverse reactions are equal

Haber Process

• Produces ammonia

• use for fertiliser production

Haber process conditions

• temp - 450 °C

• pressure - 200 atmospheres

• catalyst - iron

Predict how the position of a dynamic equilibrium is affected by changes in

• Temperature:

  • Increase: Shifts equilibrium away from the heat (endothermic direction).

  • Decrease: Shifts equilibrium toward the heat (exothermic direction).

• Pressure:

  • Increase: Shifts equilibrium toward the side with fewer gas molecules.

  • Decrease: Shifts equilibrium toward the side with more gas molecules.

• Concentration:

  • Increase Reactant: Shifts equilibrium toward the product side.

  • Increase Product: Shifts equilibrium toward the reactant side.