Topics 7 8 And 9

Question 1

What series are alkanes and what are jt the first 4

Answer 1

Homologous
Methane Ethane propane butane

Question 2

Properties of chains

Answer 2

Shorter the chain the less viscous it is and the more volitile (it turns to a glass at lower temps -lower boiling point and more flammable

Question 3

Complete combusion in hydrocarbons

Answer 3

Waster products water and co2
Hydrocarbons used as fuel due to the amount of energy released in combusion

Question 4

How is crude oil made

Answer 4

Mainly planketon formed under millions of years of high temp and pressure

Question 5

What are the uses of crude oil

Answer 5

Petrochemical industry uses some of the hydrocarbons from crude oil as feedstock to make new compounds for polymers and solvents
Oil provides differnt fuels for differnt types of transport

Question 6

Why is cracking and how do you test for alekens

Answer 6

Longer hydrocarbons turning into smaller more useful ones
When bromide water added to alkane the water will stay orange
But add bromide water to an alkene and shake it the soltuion will turn colourless

Question 7

Differnt types of cracking

Answer 7

Catalystic cracking
Heat long chain hydrocarbons to vaporise them ,pour the vapour over a hot aluminium oxide power catalyst
The molecueles will split apart
therefore cracking them
Steam cracking
Vaporise hydrocarbons ,mix with steam and then heat to a very high temp

Question 8

How does melting and boiling point tell you how pure a substance is

Answer 8

Chemically pure substance will melt and boil at a specific temp ,test the purity by measuring the melting and boiling point and comparing that to data
Impurities in a sample will lower the melting point and increase the melting range and increas the boiling point

Question 9

What’s a formulation

Answer 9

A mixture with a specific purpose

Question 10

How do you test for the 4 common gasses

Answer 10

Chlorine -bleaches damp litmus paper turning it white
Oxygen-hold glowing splint near it and the splint will relight
Carbon dioxide -bubble co2 through solution of calcium hydroxide will cause solution to go cloudy
Hydrogen-hold burning splint at open end of test tube you’ll get a squeaky pop

Question 11

Evolution of atmosphere phase 1

Answer 11

Earth surface coverd in volcanos erupted lots of gasses
How we think early atmosphere was formed
Atmosphere made up of mostly co2 and no oxygen similar to mars and Venus
Volcanic activity also released nitrogen

Question 12

Phase 2

Answer 12

Water vapour in atomposhee condensed and formed oceans
Co2 in atomposhere was removed as it dissolved in ocean and formed carbon precipitates that formed sediment on seabed
Marine animals evolved their shells containing those carbon precipitates
Green plants and algae evolved to alcarry out photosynthesis by aborning the carbon

Question 13

Phase 3

Answer 13

Plants e olives to photosynthesise and oxygen built in atmosphere meaning more conplex life could form
200 million years ago the atmosphere reached one similar to today

Question 14

How does fossil fules form and what is coal and limestone

Answer 14

Plants and plankton die and fall to seabed
Over millions of years they compress and form oils and sedimentary rocks (trapping carbon within them )
Coal is sedimentary rock made from plant deposits
Limestone is sediments rocks made from calcium carbonate

Question 15

How does the earth warm up

Answer 15

Greenhouses gasses act like an insulting layer to earth trapping the heat in
Greenhouse gasses don’t absorb short wave lengths but they do absorb the long wavelength radiation that gets reflected back to earth
Then they reraditate it in all directions
Thsi warms up the earth and. Is called the greenhouse effect

Question 16

Why are carbon footprints difficult to measure

Answer 16

Due to their being so many different factors to measure ,emotions released from manufacturing,emissions produced when using it and when it’s is disposed

Question 17

What ways reduce co2 emissions

Answer 17

Renewable energy sources
Using more efficient processes could conserve energy and cut waste
Goverment could tax companies or individuals on how much greenhouse gasses they emit

Question 18

What are the 2 problems of incomplete combustion

Answer 18

Particulates
Dangerous if Inhaled can stick to lungs and cause damage
Bad for environment ,reflect sunlight back into space ,less light reaches earth ,causing global dimming

Carbon monoxide
Is dangerous due it stopping blood from carrying oxygen around the body
It does this by binding to the haemoglobin
Lack of oxygen in blood leads to fainting coma or death

Question 19

How is acid rain produces and what’s the issues of it

Answer 19

Sulfur dioxide is released during combustion of fossil fuels and in air it becomes oxidised
Nitrogen oxides are made between nitrogen and oxygen caused by the heat of burning
These gasses mix with water and clouds nand form either diluted sukfic acid or diluted nitric acid and then falls as rain
Acid rains kills plants corrodes metal ,contaminated water supply and causes respiratory problems if brethee in