Chemistry of Environment A deeper dive into the Hussin put 3af
10.1 WATER
Chemical tests for water ✿Using anhydrous cobalt(II) chloride [blue to pink] ✿Using anhydrous copper(II) sulfate [white to blue] How to test water purity ✿Boiling, so impure water will boil at temperatures above 100°C ✿Melting, so impure water will melt at temperatures below 0°C Distilled water during experiments ✿Distilled water is used in practical chemistry because of its high purity Tap water contains more impurities which could interfere with chemical reactions so is typically not used
Substances in natural water sources :✿Dissolved oxygen ✿Metal compounds ✿Plastics ✿Sewage ✿Harmful microbes ✿Nitrates from fertilisers ✿Phosphates from fertilisers and detergents Beneficial substances ✿Dissolved oxygen - essential for aquatic life ✿Metal compounds - some provide essential minerals which are necessary for life, suchas calcium and magnesium
Harmful substances ✿Metal compounds - some are toxic like aluminium and lead ✿Some plastics - these may be harmful to aquatic life in many ways ✿Sewage - contains harmful microbes which can cause disease ✿Nitrate & phosphates from fertilisers - these can promote the growth of aquatic plant life which leads to deoxygenation of water. Ultimately, this can cause damage to aquaticlife in a process called eutrophication Treatment of domestic water supply ✿Mud, sand and other particles will fall to the bottom of the tank due to gravity and form a layer of sediment, in a process called sedimentation ✿Filtration is the process used to remove smaller particles by passing the water through layers of sand and gravel filters that trap solid particles
✿Carbon is used to removed bad odors and smell ✿Chlorination is the addition of chlorine to the water supply which kills bacteria and other unwanted microorganisms
10.2 fertilisers
Common fertilisers ★Ammonium salts and nitrates are commonly used as fertilisers Uses of NPK fertilisers ★Fertilisers contain nitrogen, potassium and phosphorus ★Nitrogen makes chlorophyll and protein and promotes healthy leaves ★Potassium promotes growth and healthy fruit and flowers ★Phosphorus promotes healthy roots
10.3 Air quality and climate
Composition in air ♣︎78% Nitrogen, 21% Oxygen, and the rest being mixtures of carbon dioxide and noble gases Sources of air pollution ♣︎carbon dioxide from the complete combustion of carbon-containing fuels ♣︎carbon monoxide and particulates from the incomplete combustion of ccarboncontaining fuels ♣︎ethane from the decomposition of vegetation and waste gases from digestion in animals ♣︎oxides of nitrogen from car engines. ♣︎sulfur dioxide from the combustion of fossil fuels which contain sulfur compounds
Effects of air pollutants ♣︎Carbon dioxide: higher levels of carbon dioxide leading to increased global warming. Which leads to climate change. ♣︎Carbon monoxide: toxic gas ♣︎Particulates: increased risk of respiratory problems and cancer ♣︎Methane: higher levels of methane leading to increased global warming, which leads to climate change ♣︎Oxides of nitrogen: acid rain, photochemical smog and respiratory problems ♣︎Sulfur dioxide: acid rain
Strategies to reduce the effects of climate change ♣︎Planting trees, reduction in livestock farming, decreasing use of fossil fuels, increasinguse of hydrogen and renewable energy., for example, wind energy and solar energy Strategies to reduce the effects of acid rain ♣︎The use of catalytic converters in vehicles, reducing emissions of sulfur dioxide by using low-sulfur fuels and flue gas desulfurisation with calcium oxide Photosynthesis The reactants for this reaction are carbon dioxide and water Glucose and oxygen are produced ♣︎ Carbon dioxide + water → glucose + oxygen
Greenhouse gases cause climate change source: savemyexams
Catalytic converters ♣︎Present in car exhausts: contains transition metal catalysts of platinum andrhodium ♣︎Aids redox reactions to neutralize toxic pollutants formed as a result of incomplete fuel combustion: (a) carbon monoxide, (b) nitrogen oxides, (c) unburned hydrocarbons ♣︎A single reaction can summarise the reaction of nitrogen monoxide and carbon monoxide within a catalytic convertor: 2NO + 2CO → N2 + 2CO2
The end May Allah easeyour studiesand help you rememberall the knowledgesyou have poured effort into remembering