| Potable water definition | Water that is safe for consumption |
| How is potable water produced? | Water is filtered through wire meshes to remove solids
Water is then sterilised to kill harmful bacteria |
| Method to desalinate sea water | Test pH with pH meter
Neutralise water if pH is too high or low with titration
Complete a flame test to test for sodium ions [sodium chloride]
If present flame will be yellow, so add dilute nitric acid and silver nitrate solution
Heat in a distillation apparatus
Water will evaporate leaving salts behind, and will condense into potable water
Retest pH to ensure water is neutral |
| Differences in treatment waste water, salt water, ground water and sewage water | Waste water- must remove organic matter and harmful microbes
Salt water- must be pH tested and distilled
Ground water- filtered and sterilised
Sewage water- must go through screening, sedimentation and anaerobic digestion |
| Phytomining definition | Where metals are extracted from their ions which are absorbed by plants through their roots |
| Bioleaching definion | Extraction of metals from their ores through the use of living organisms |
| Describe the process of phytomining | Plants absorb mineral ions
Plants are harvested and burned producing ash
Acid is added to ash to produce leachate
Copper can be obtained through displacement with scrap iron |
| Describe the process of bioleaching | Bacteria are used to break down ores to produce leachate
Copper ions in leachate are displaced by scrap iron |
| Advantages and disadvantages of phytoming | It is a slow process
Reduces need of mining
Conserves limited supply of high-grade ores
Reduces rock waste |
| Advantages and disadvantages of bioleaching | Produces toxic substances
Reduces need for mining
Conserves high-grade ores
Reduces rock waste |
| Purpose of the Haber process | Used to make ammonia for fertilisers |
| Haber process reaction | Nitrogen + hydrogen <=[iron catalyst]=> ammonia + heat
N2 + 3H2 <=> 2NH3 + heat |
| When is the yield of ammonia higher? | When the temperatures are lower |
| What is the optimum temperature for the Haber Process? | 450 degrees |
| What also increases the yield of ammonia? | Increasing pressure |
| What is the optimum operating pressure? | 200 atmospheres |
| What does the iron catalyst do? | Increase rate of reaction, doesn't affect yield |
| What is the trade off between rate of reaction and position of equilibrium? | Lower temperatures means the rate of reaction is slower and equilibrium is reached more slowly |
| What limits the Haber process commercially? | Expense of equipment to contain process safely, temperature of process and pressure process is completed under |
| What are NPK fertilisers? | Formulations of various salts including nitrogen, phosphorus and potassium at specific percentages |
| Describe the composition of NPK fertilisers | Comprised of nitrogen, phosphorus and potassium in specific percentages |
| How are NPK fertilisers made? | In the Haber process |
| How is ammonium sulphate [a fertiliser] made in a lab? | Drops of methyl orange indicator added to a set volume of ammonia sulfate solution in a conical flask
Dilute sulfuric acid is added until turns orange
When volume of sulfuric acid added is recorded then neutral ammonia sulfate with indicator is thrown away
Experiment is repeated without indicator with same volumes of sulfuric acid and ammonia
Ammonium sulfate is crystallised and then dried |
| What salt is produced when phosphate rock reacts with nitric acid? | Calcium nitrate and phosphoric acid |
| What salt is produced when phosphate rock reacts with sulfuric acid? | Single superphosphate |
| What salt is produced when phosphate rock reacts with phosphoric acid? | Triple superphosphate |
