Revision topic 12

Question 1

what is crude oil

Answer 1

It is a mixture containing compounds that are not chemically boned and have different boiling points made of hydrocarbons

Question 2

what is fractional distillation

Answer 2

It is a process that separates liquids with different boiling points

Question 3

why isn’t crude oil good straight from the ground

Answer 3

because it has many substances in it

Question 4

what are alkanes

Answer 4

they are saturated hydrocarbons with single bond between the carbon atoms

Question 5

what is the formula for alkanes

Answer 5

C(n)H(2n+2)

Question 6

what are the properties of short-chain molecules vs long-chain molecules and which one is more useful

Answer 6

short chains have lower boiling point have higher volatility, lower viscosity, and higher flammability making the short chains more useful

Question 7

how does fractional distillation work

Answer 7

crude oil is fit into a bottom of a long tower with many fractions each has its own temperature with the temperature getting cooler as you go up the crude oil is heated breaking up the mixture with each substance in the mixture is collected from the column with its boiling point

Question 8

how can fuels cause pollutions

Answer 8

1. they are sulfur impurities in fuel so once it is burned sulfur would react with oxygen forming sulfur oxide which is a toxic gas that causes acid rain, we can avoid this by filtering out the impurities
2. also when burning fuels with carbon in them, that would release carbon which would react with oxygen forming carbon dioxide that’s is a factor in climate change since its a greenhouse gas
3. also incomplete combustion because of lack of oxygen cause carbon monoxide, which a toxic gas that shouldn’t be in our bodies
4. also nitrogen and oxygen would react in high temperatures in engines forming nitrogen oxide which is a toxic gas that can cause acid rain
5. in diesel engines hydrocarbons with burn with large molecules sometimes these large molecules don’t burn completely this would cause tiny particles called carbon (soot) and unburnt hydrocarbons to be produced hence causing global dimming

Question 9

what are biofuels

Answer 9

they are fuels made from plants or animals products it is considered renewable

Question 10

what are the advantages of biofuel

Answer 10

1. it is less harmful to animals
2. it burns more cleanly
3. it is renewable
4. it is CO2 neutral

Question 11

how does biofuel release carbon

Answer 11

1. from fertilizing and harvesting crops
2. from extracting and processing the biofuel
3. from transporting the plant material

Question 12

what are the disadvantages of biofuel?

Answer 12

it is required to use up a lot of farmland in order to get biofuel this can cause famine in poorer countries and also taking the farmland can endanger species by the destruction of their habitat

Question 13

compare hydration vs fermentation

Answer 13

fermentation is a slow process that makes ethanol from sugar canes now it is advantages because it CO2 neutral, it burns cleaner than fossil fuels, it’s renewable and safer for animals but it is very slow can take up products that could be used for food, can destroy animals habitats, hydration is a process where steam is reacted with ethene over a high pressure plus phosphoric acid catalysts this process is very fast and produces a lot of energy and can be converted back easily but it releases CO2 and it isn’t renewable it might have sulfur impurities that would form sulfur dioxide