Question 1
While Hiking, water can be purified in the following ways:
| Method | Effectiveness | Cost |
|
Boiling |
Sterilizes by disease-causing micro-organisms, but does not remove impurities
May provide activation energy for toxic reactions to occur |
High fuel consumption
Bring to a boil and continue boiling for at least 1 minute |
|
Filtration |
Filters away most micro-bacteria, sediments, and water parasites
With activated charcoal filters, able to filter out even more organic compounds, toxic substances, and chemical contaminants |
Expensive
Commercially available, but not common
|
|
Iodine Tablets |
Kills many common pathogens present in fresh water, but does not remove sediments or chemical pollutants
Leaves unpleasant aftertaste that can be reduced with Vitamin C tablets |
Cheap
Commercially available, available at many pharmacies
Waiting time of at least 30 mins before consumption |
Question 2
Desalination techniques are not used more widely to produce potable water because its uses a lot of energy to produce potable drinking water therefore its is not economical and not effective.
Question 3
3a) Major source of lead in water could be from the corrosion of pipes leading to leaching of lead into the water supply
3b) Research activities done in the chemistry lab should not be accounted for the elevated lead levels in water as any waste made in the lab would have been properly disposed. Furthermore, chemical waste are not allowed to be disposed into the sink.
Question 4
I would expect water soluble vitamins to be polar compounds and fat soluble vitamins to be non polar compounds.
Polar compounds can form permanent dipole- permanent dipole interactions with water or if H in the vitamin is bonded to F,O or N, hydrogen bonds can be formed with water.
Non polar compounds can only form induced dipole- induced dipole interaction (London dispersion forces) with other molecules and so they dissolve in fat which has the same type of intermolecular forces.
In short, “like dissolves like” and molecules that can form the same types of bonds are more soluble in one another. E.g Hydrogen bond with another type of molecule that form Hydrogen bonds.