Chemistry of the environment Details/Definitions Flashcards
Chemical reaction of water and anhydrous copper(II) sulfate
CuSO₄(s) + 5H₂O(l) → CuSO₄.5H₂O(s)
Water turns anhydrous copper(II) sulfate…
from white to blue
Chemical reaction of water and anhydrous cobalt(II) chloride
CoCl₂(s) + 6H₂O(l) → CoCl₂.6H₂O(s)
Water turns anhydrous cobalt(II) chloride…
from blue to pink
How to test for the purity of water using melting and boiling points
-Heating it and observing when it boils(pure water should have a boiling point of 100°C; If we heat a liquid and it begins to boil either below or above 100°C, the liquid contains impurities)
-Cooling it and observing when it freezes(pure water should have a freezing point of 0°C; If we cool a liquid and it begins to freeze either below or above 0°C, the liquid contains impurities.)
Why is distilled water used instead of practical water in chemistry
Distilled water contains fewer chemical impurities
Substances in water
-Dissolved oxygen
-Metal compounds
-Plastics
-Sewage
-Harmful microbes
-Nitrates from fertilizers
-Phosphates from fertilizers and detergents
Beneficial substances in water
-Dissolved oxygen(for aquatic life)
-Some metal compounds(provide essential minerals for life)
Potentially harmful substances in water
-Some metal compounds(are toxic)
-Some plastics(harm aquatic life)
-Sewage(contain harmful microbes which cause disease)
-Nitrates and phosphates(lead to deoxygenation of water and damage to aquatic life)
Process of treatment of domestic water supply
-Sedimentation and filtration(to remove solids)
-Use of carbon(to remove tastes and odours)
-Chlorination(to kill microbes)
Chlorination
The process of adding chlorine to drinking water in order to kill parasites, bacteria and viruses
Ammonium salts and nitrates are used as…
fertilisers
Use of NPK(nitrogen/phosphorus/potassium) fertilizers
Provide the elements nitrogen, phosphorus and potassium in the soil for improved plant growth
Percentage of nitrogen in clean, dry air
78%
Percentage of oxygen in clean, dry air
21%
Apart from nitrogen and oxygen, clean air also contains…
a mixture of noble gases and carbon dioxide
Source of carbon dioxide
The complete combustion of carbon-containing fuels
Source of carbon monoxide and particulates
The incomplete combustion of carbon-containing fuels
Source of methane
-The decomposition of vegetation and waste gases from digestion in animals
-Cracking hydrocarbons
Source of oxides of nitrogen
Car engines
Source of sulfur dioxide
Acid rain
How greenhouse gases carbon dioxide and methane cause global warming
They absorb, reflect and emit thermal energy into the atmosphere, hence reducing the amount of thermal energy lost to space
Strategies to reduce the effect of climate change
-Planting trees
-Reduction in livestock farming
-Decreasing use of fossil fuels
-Increasing use of hydrogen and renewable energy(eg. wind, solar, etc.)
Strategies to reduce the effect of acid rain
-Use of catalytic converters in vehicles
-Reducing emissions of sulfur dioxide(by using low sulfur fuels and flue gas desulfurization with calcium oxide)
