Environmental Chemistry Flashcards
What are gases which cause the greenhouse effect mainly referd to as?
Chloro-flouro-carbons (CFC’s)
Describe the greenhouse effect, and also state why it is important
Gases like carbon dioxide, methane CFC’s, water vapour and oxides of nitrogen trap the infra-red radiation (heat) from the sun and keeps it near the earth’s surface, to maintian a global average temperature of 5 degrees celcius. This makes life possible on earth.
Describe the greenhouse effect in terms of wavelength
CFC’s allow heat in short wavelengths to pass through, but the long wavelenghts wich are re-radiated are reflected by CFC’s
Why is the amount of carbon dioxide in the air increasing?
- Increase in burning of fossil fuels
- Deforestation
Give a name to the gradual increase in temperatures and change in global climate
Global warming
What causes global warming?
The greenhouse effect “overworks” because there are to many CFC’s (especially carbon dioxide)
Name one property of ozone, and also state the reason for this property
- One of the most vigorous oxidizing agents
- Molecules have much more energy than oxygen molecules
Name two domestic uses of ozone, and state why ozone is suitable for these uses
- Antiseptics, destroys bacteria
- Bleach, causes colours to fade rapidly
What is the function of ozone in the upper atmosphere?
Absorbs ultraviolet light and converts it to less harmful radiation.
Name the main air pollutants in our atmosphere
- Carbon monoxide
- Unburnts hydrocarbons
- Sulphur dioxide
- Oxides of nitrogen
- Lead compounds
Name the effects of carbon monoxide
- Stops red blood cells from carrying oxygen from the lungs to the rest of the body.
- Can cause death and is highly poisenous
Name the effects of unburnt hydrocarbons
- Smell horrible
- Cause liver damage and cancer
Name the effects of sulphur dioxide
- Attacks lungs and breathing tubes causing bronchitis and other diseases
- Dissolves in rainwater, casuing acid rain
- Acid rain damages trees, plants limestone buildings and metal work
- Has a devastating effect on aquatic life
Name the effects of nitrogen oxides
- Attacks the breathing system
- Causes acid rain
Name the effects of lead compounds
- Brain damage, especially children
Explain into what harmful gases are converted to inside a catalytic converter, and also state the catalyst
- CO to CO2 (platinum)
- NO to N2 (rhodium)
- Unburnt hydrocarbons to water & CO2 (palladium)
Name three problems with catalytic converters
- Works only with unleaded petrol
- Lowers fuel economy
- Does not work in cold conditions
Why are fertilisers added to soil?
To stimulate plant growth
What is nitrogen used for in plants?
Formation of proteins
What is phosphorus used for in plants?
- Disease and frost resistence
- Good root growth
- Formation of DNA
What is potassium used for in plants?
- Photosynthesis
- Respiration
- Formation of seeds
Why is molecular nitrogen so unreactive?
Due to the strong tripple covalent bonds between atoms
State the ratio in which nitrogen, phosphorus and potassium appear in fertilisers
N : P : K
2 : 3 : 2
State the dangers of overuse of fertilisers
- Eutrophication
- Converts oxygen carrying haemoglobin in red blood cells into a form incapable of carrying oxygen
Why is methane gas a hazard in dumping sites?
It is flammable and can cause a fire risk to the surrounding environment
Name a disease transmitted by flea-carrying pests
Bubonic plague
Name the dangerous chemicals found in dumping sites and also their effects
- Lead affects the brain and nervous system
- Mercury is very poisenous
- PVC (vinyl chloride) affects health over a prolonged period
- Benzene is very toxic
- Arsenic is used as poison
- Carbon tetrachloride penetrates the skin and the heavy vapour is toxic
- Cigarette butts contain nicotine which cause lung diseases
Describe the financial, economical and ecological implications of dumping
- Local cost to industry clearing illegal dumping sites is increasing
- Service fees or property taxes of residents increase
- One option of limiting is recycling
Show the three steps of ozone decomposition in the atmosphere, along with the overall process
- 2NO + O2 2NO2
- NO2 → NO + O
- O + O2 O3
NO + O3 ⇋ NO2 + O2
