Mod 7.2 - Hydrocarbons Flashcards
What are single bonds?
One shared pair of electrons; C-C
What are double bonds?
Two shared pairs of electrons; C=C
What are triple bonds?
Three shared pairs of electrons; C☰C
What are the angles between bonds of a tetrahedral?
109.5 degrees
What are the angles between bonds of a Planar?
120 decrees
What are the angles between bonds of a linear?
180 degrees
What is the geometrical arrangement of bonds and angle between bonds for ‘four single bonds around the carbon atom’
Tetrahedral - 109.5 degrees
What is the geometrical arrangement of bonds and angle between bonds for ‘One double and two single bonds around the carbon atom’
Planar - 120 degrees
What is the geometrical arrangement of bonds and angle between bonds for ‘two double bonds around the carbon atom’
Linear - 180 degrees
What is the geometrical arrangement of bonds and angle between bonds for ‘One triple and one single bond around the carbon atom’
Linear - 180 degrees
What is the general formula of alkanes?
C(n)H(2n+2)
What is the general formula of alkenes?
C(n)H(2n)
What is the general formula of alkynes?
C(n)H(2n-2)
What is the procedure required to safely handle and dispose of organic substances?
There is the use of a safety data sheet as a document which is prepared by the manufacturer or importer of a hazardouz chemical
This provides info on the chemical and how to handle it safely including storage and disposal
How can organic substances enter the body? (3)
Inhalation through the lungs
Absorption through the skin
Ingestion (swallowing)
What are the consequences of organic substances entering the body?
It can cause varying degrees of damage depending on the chemical
What substances can be poured down the sink as a safe disposable of organic substance after being diluted?
Organic substances that are water miscible(A miscible liquid can be mixed with another liquid ) - includes short chained alcohols and short chained ketones.
These substances are readily consumed by microorganisms in the sewer but are highly flammable
Are different types of waste kept in the same place?
No, they are often kept separate and disposed of differently
What is used for water-immiscible organig wastes?
A waste container, as it shouldnt be washed down the sink.
What are the two types of water immiscible organic wastes?
Non-halogenated organic waste
Halogenated organic waste
Why shouldnt non halogenated organic waste by washed down the sink?
Non halogenated organic waste includes hydrocarbons, floats on top of water and can form an explosive vapour
Why shouldnt halogenated organic waste by washed down the sink?
Halogenated organic wastes (contains halogen in the compound) are also flammable, can form toxic halogenated compounds during combustion and many are highly toxic to aquatic life
What are our primary source of hydrocarbons?
Fossil fuels - they are non renewable resources, formed from the remains of prehistoric animals and plants.
Three types of fossil fuels include; coal, crude oil and natural gas
What are the environmental implications of obtaining and using hydrocarbons from the Earth?
The combustion of hydrocarbon fuels releases carbon dioxide (CO2), as well as other greenhouse gases that contribute to atmospheric pollution and climate change.
Materials produced by the chemical industry using components of crude oil as the raw materials are non-biodegradable. Therefore, their disposal poses an environmental concern, particularly in the long-term as the amount of non-biodegradable materials being used accumulate
Oil spills impose significant damage to the environment especially aquatic ecosystems. Oils spills are also difficult to clean up.
What are the economic implications of obtaining and using hydrocarbons from the Earth?
Significant economic growth for countries that have access to oil reservoirs as crude oil forms a major party of their export.
The exponential use of petroleum led to dwindling supplies and high costs of this non-renewable fossil fuel and by the late 1900s it became evident that traditional materials needed to be supplemented or replaced by others derived from renewable resources.
Electrical energy, once largely provided by the burning of fossil fuels such as coal in power stations, is now supplemented by the use of batteries and the development of the renewable energy industry. Renewable energy production is not only environmentally but also more economically viable in the long-term.
What are the sociocultural implications of obtaining and using hydrocarbons from the Earth?
During the twentieth century, the world population increased significantly. With this increase in population came increased demands for materials such as fuels for transport, industry and heating, materials for construction to replace and supplement timber and iron, fibres for clothing and household goods and chemicals to improve medical care. For a large part of that century, the demands were satisfied by hydrocarbons in fossil fuels.
As the demands for liquid fuels for transport increased, crude oil refining increased, and crude oil provided not only petrol, diesel and aviation fuel but also chemicals such as ethylene, which is an essential raw material for polymer production.
Chemical industries based around fossil fuels developed. These included manufactures of polymers, such as polyethylene, PVC and polystyrene, as well as synthetically produced materials including esters, acids, alcohols, nylon, polyesters, synthetic rubber. These chemicals, based on the petroleum industry, changed the lifestyles of society.
How do you deal with the handling of organic substances? (5)
Store “like material with like” – so that flammable materials should be stored together and away (in a different cabinet) from materials that are corrosive, toxic, etc to prevent hazardous reactions.
Oxidising agents must be stored separately from organic substances as they can ignite organic solvents or acids.
Organic nitrates and peroxidies are shock-sensitive and should be handled with care as shock can result them in generating large volume of gases in a short period of time, resulting in a high increasing pressure. This would result in an explosion.
Some organic acids such as acetic and propanoic acid are corrosive which can cause burns upon contact with skin where severity depends on concentration of the acid. TO minimise the risk, lab coat, safety gloves and goggles should be used. Enclosed leather shoes also needed
Ensure that a well-ventilated area such as a fume hood is used when handling flammable, volatile organic substances (e.g. alcohols). This is because the inhalation of alcohol can cause dizziness and could result in brain damage depending on duration of exposure.
What precaution should you use before leaving the lab?
Wash your hands before leaving the laboratory, even if gloves are worn as a safety precaution especially after cleaning up a spill. This is because organic solvents can strip off your skin’s natural oil layer resulting in skin irritation whereby your skin would be more susceptible to absorbing toxic chemicals.
What are intermolecular forces?
It is an attractive force that can be found between molecules?
WHat are the 3 types of intermolecular forces?
Dispersion forces
Dipole-Dipole forces
Hydrogen bonding