Organic chemistry

• What is crude oil? A finite resource that is used to produce fuels and other chemicals
• How is crude oil formed? Formed over millions of years from the fossilised remains of plankton
• Where is crude oil found? In the porous rocks in the Earth's crust
• What are hydrocarbons? Is a compound that is made out of only hydrogen atoms and carbon atoms
• What are most compounds in crude oil made up of? Hydrocarbons
• What do hydrocarbons affect if they vary in size? [2] - Properties - How they can be used as fuels
• The larger the hydrocarbon, the more? [4] - More viscous - Higher its boiling point - Less volatile - Less easy for it to ignite
• How can crude oil be separated into different fractions (parts)? By fractional distillation
• What does each fraction contain? Hydrocarbon molecules with a similar number of carbon atoms
• What are most of the hydrocarbons obtained? Alkanes
• What happens during fractional distillation? [3] - Crude oil is heated until it evaporates - Vapour moves up the fractionating column - Hydrocarbon molecules condense and are collected at different temperatures
• What happens to the shorter hydrocarbon molecules in a fractionating column? They reach the top of the fractionating column before they condense and are collected
• What happens to the longer hydrocarbon molecules in a fractionating column? They condense at higher temperatures and are collected lower down the column.
• What are carbon atoms linked to? Four other carbon atoms by a single bond
• How many bonds do alkanes contain? Single bond
• What are alkanes described as? Saturated hydrocarbons
• Why are alkanes described as saturated hydrocarbons? Because they contain the maximum number of bonds possible
• How reactive are alkanes, and do they burn well? Fairly unreactive, but they burn well
• What is the general formula for alkanes? CnH2n+2
• What is methane? Methane is the simplest alkane.
• What is methane made up of? 4 hydrogen atoms and 1 carbon atom
• What is ethane made up of? A molecule made up of 2 carbon atoms and 6 hydrogen atoms.
• What is propane made up of? A molecule made up of 3 carbon atoms and 8 hydrogen atoms.
• What do shorter-chain alkanes release? [2] - Shorter-chain alkanes release energy more quickly by burning - So there is a greater demand for them as fuels
• What are most fuels compounds of? Carbon and Hydrogen
• What do many fuels also contain? Sulfur
• What happens during combustion of hydrocarbon fuels? [3] - Both carbon and hydrogen are oxidised - Energy is released - Waste products are produced
• What happens to the waste products produced during the combustion of hydrocarbon fuels? They are released into the atmosphere
• What happens if combustion is not complete? Then carbon monoxide, unburnt fuels and solid particles including soot (carbon) may be released
• What is carbon monxide? A colourless, odourless and toxic gas
• What effects does carbon monoxide have on organisms or the enviroment? [1] Decreases energy levels in the lungs which can cause severe difficulties
• What are solids particles in the air called? Particulates
• How are particulates formed? A result of complex reactions of chemical such as sulpur dioxide and nitrogen oxides
• What effect does particulates have on organisms or the enviroment? [4] - Global dimming - Premature death in people who have a lung or heart disease - Irregular heartbeat - Non-fatal heart attack
• What is global dimming? Reducing the amount of sunlight reaching the Earth's surface
• How is nitrogen oxide produced? From combustion reactions.
• What effects does nitrogen oxide have on organisms or the enviroment? [3] - Causes damage to the human respiratory system - Increases an individual's vulnerability to respiratory infections and asthma - Long term expose = Chronic lung disease
• How is sulpfur dioxide produced? [2] - Burning fossil fuels - Smelting of mineral ores that contain sulphur
• What effect does sulpfur dioxide have on organisms or the enviroment? [2] - Formed into acid rain which could kill organisms and disrupt the enviroment. - Erode buildings made up of limestone
• How is carbon dioxide produced? [2] - From respiration - Machinery