Environmental problems

Question 1

what are the main burners of fossil fuels?

Answer 1

power stations and cars

Question 2

what happens during combustion of crude oil and coal?

Answer 2

the carbon and hydrogen are oxidised so that carbon dioxide and water vapour are released into the atmosphere (and energy)

Question 3

what happens if the fuel contains sulfur impurities?

Answer 3

the sulfur will released as sulfur dioxide when the fuel is burnt

Question 4

if the fuel is burned at a high temperature, what will also be produced?

Answer 4

oxides of nitrogen

Question 5

what is complete combustion?

Answer 5

when there is plenty of oxygen and all the fuel burns `

Question 6

what is partial combustion?

Answer 6

when there is not enough oxygen and some of the fuel doesn’t burn, particulates of soot (carbon) and unburnt fuel are released. carbon monoxide is also released

Question 7

what is the gas that causes acid rain?

Answer 7

sulfur dioxide

Question 8

how is acid rain formed?

Answer 8

the sulfur dioxide released mixes with the clouds and forms sulfuric acid, which forms as acid rain

Question 9

what effects can acid rain have?

Answer 9

causes lakes to become acidic and many plants and animals die as a result, kills trees and damages limestone buildings and stone statues

Question 10

disadvantages of removing sulfur from fuels before they are burnt

Answer 10

costs more to do it, takes more energy which comes from burning more fuel releasing more of the greenhouse gas carbon dioxide

Question 11

how do power stations take out the harmful gases before releasing their fumes into the atmosphere?

Answer 11

they have acid gas scrubbers

Question 12

what is happening to the level of carbon dioxide in the atmosphere and why?

Answer 12

it is increasing because of the large amounts of fossil fuels humans burn

Question 13

what is carbon dioxide causing?

Answer 13

global warming-the average temperature of the earth has increased

Question 14

what types of climate change can global warming cause?

Answer 14

changing rainfall patterns and severe flooding due to the polar ice caps melting

Question 15

what is global dimming?

Answer 15

in some areas nearly 25% less sunlight has been reaching the surface of the earth compared to 50 years ago.

Question 16

what is global dimming caused by?

Answer 16

particles of soot and ash that are produced when fossil fuels are burnt reflect sunlight back into space, or they can help to produce more clouds that reflect the sunlight back into space

Question 17

alternative fuels to fossil fuels

Answer 17

ethanol, biodiesel and hydrogen gas

Question 18

how is ethanol produced?

Answer 18

from plant material (so known as a biofuel), made by fermentation of plants and is used to power cars, often mixed with petrol to make a better fuel

Question 19

pros of ethanol

Answer 19

it’s carbon neutral- the CO2 released when it’s burnt was taken in by the plant as it grew
only other product is water

Question 20

cons of ethanol

Answer 20

engines need to be converted before they’ll work with ethanol fuels.
ethanol fuel not widely available
worries that as demand for it increases farmers will switch from growing food crops to growing crops to make ethanol, so food prices will increase

Question 21

how is biodiesel produced?

Answer 21

from vegetable oils such as rapeseed oil and soybean oil, can be mixed with ordinary diesel fuel and used to run a diesel engine

Question 22

pros of biodiesel

Answer 22

‘carbon neutral’
engines don’t need to be converted
produces much less sulfur dioxide and ‘particulates’ than ordinary diesel or petrol

Question 23

cons of biodiesel

Answer 23

can’t make enough to completely replace diesel
expensive to make
could increase food prices if farmers switch from growing food crops to growing crops to make biodiesel (due to increase in demand)

Question 24

how is hydrogen gas produced?

Answer 24

from the electrolysis of water, electrical energy needed to split water up which can come from a renewable source e.g solar

Question 25

pros of hydrogen

Answer 25

combines with oxygen in the air to form just water-very clean

Question 26

cons of hydrogen

Answer 26

need a special, expensive engine
hydrogen isn’t widely available
still need to use energy from another source to make it
hard to store