topic 4: extracting metals and equilibria

Question 1

bacterial extraction

Answer 1

a method of metal extraction which uses bacteria to extract metals from their ores. the bacteria breaks down low grade ores to produce an acidic solution containing metal ions

Question 2

cation

Answer 2

a positively charge ion. metals tend to form cations. formed when an atom loses at least one electron.

Question 3

displacement

Answer 3

a chemical reaction in which a more reactive element displaces a less reactive element from its compound

Question 4

dynamic equilibrium

Answer 4

a reversible reaction will reach dynamic equilibrium when the rate of the forward reaction is equal to the rate of the backward reaction. at dynamic equilibrium, the concentration of reactants and products remains constant

Question 5

electrolysis

Answer 5

the splitting up of an ionic compound using electricity. the electric current is passed through a substance causing chemical reactions at the electrodes which leads to the decomposition of the materials, electrolysis is used for metal extraction if the metal is more reactive than carbon

Question 6

haber process

Answer 6

an industrial process which produces ammonia from the reaction between nitrogen and hydrogen. the reaction conditions are 450C and 200 atm and it requires an iron catalyst

Question 7

life cycle assessment

Answer 7

the analysis of the impact a product has on the environment. it considers the raw materials, manufacturing, packaging, transportation, product use and disposal

Question 8

ore

Answer 8

a type of rock which contains metal compounds, the metals or metal compound are present in sufficient amounts making it work extracting them

Question 9

oxidation

Answer 9

a reaction involving the gain of oxygen. oxidation is the loss of electrons

Question 10

phytoextraction

Answer 10

a method of metal extraction which uses plants to absorb the metal compounds through their roots. the plants are then burned so that the metal compound can be removed from the ash

Question 11

reactivity series

Answer 11

a series in which metals are arranged in order of their creativity. this can be used to predict products from reactions

Question 12

redox reaction

Answer 12

a reaction in which both oxidation and reduction occur simultaneously

Question 13

reduction

Answer 13

a reaction involving the loss of oxygen. reduction is the gain of electrons

Question 14

reduction with carbon

Answer 14

process used to extract metals from their oxides when the metal is less reactive than carbon. the metal oxide is heated with carbon so that the carbon reduces the metal oxide to the metallic element

Question 15

reversible reaction

Answer 15

a reaction in which the products can react together to reform the reactants. reversible reactions are denoted by the symbol