Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Chemistry C123 > C1 > Flashcards

C1 Flashcards

(60 cards)

Start Studying
1
Q

What is the air made up of? What are the percentages of each gas?

A 
Nitrogen: 78%
Oxygen: 21%
Argon: 1%
Carbon Dioxide: 0.04%
(other gases like water vapour are included)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In general, what actually is ‘air’ ?

A

A mixture of different gases consisting of small molecules with large spaces in between them.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is affecting the change in atmosphere and air quality?

A

Human activity or by natural processes (e.g. volcanoes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the evolution of the atmosphere.

A
  1. Earth’s surface was originally molten. Volcanoes released huge amounts of CARBON DIOXIDE, WATER VAPOUR and NITROGEN (no oxygen) and lava & dust.
  2. As the water vapour condensed, oceans formed and the Earth cooled.
  3. Simple bacteria-like creatures evolved to use photosynthesis.
  4. These creatures removed CO2 from the air and released oxygen. This allowed complex organisms (i.e. animals) to evolve.
  5. CO2 was removed by plants and animals died and were buried. These soon became fossil fuels.
  6. CO2 dissolved in the ocean reacts with the salt to form calcium carbonate. This formed SEDIMENTS which become buried and cemented to make SEDIMENTARY ROCKS.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What five pollutants have been added by human activity (in small amounts) ?

A
  1. Carbon Dioxide
  2. Carbon Monoxide
  3. Carbon Particulates
  4. Sulfur Dioxide
  5. Nitrogen Oxides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How are the pollutants formed (in general) ?

A
  1. From burning fuels and vehicles.

2. It can also be released by nature, e.g. volcanoes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the difference between direct and indirect harm?

A

Direct harm: Things that would directly harm humans, e.g. diseases or death to people who breathe in CO

Indirect harm: Things that do not directly harm humans but harm the environment which LEADS TO harming us, e.g. Carbon Dioxide –> Global Warming –> Drowning to humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is needed for any fuel to burn and release energy?

A

Oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Fossil fuels such as petrol, diesel and fuel oil are examples of what?

A

Hydrocarbons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are Hydrocarbons?

A

Compounds that only contain CARBON and HYDROGEN atoms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the reaction when a hydrocarbon fuel is burned?

A

Hydrocarbon Fuel + Oxygen –> Carbon Dioxide + Water (+Energy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is Oxidation?

A

When oxygen is ADDED to a substance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is Reduction?

A

When oxygen is REMOVED from a substance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is Combustion (burning) ?

A

An OXIDATION reaction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What can Pure Oxygen do to fuels? What is an example of using Pure Oxygen?

A

It can make fuels burn more RAPIDLY and at a HIGHER temperature.
E.G. An oxy-fuel welding torch (it can melt steel!)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is Coal mostly made out of?

A

It’s mainly Carbon. It contains lots of impurities, though.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

In a chemical reaction the ______ of the reactants and products are _______.

A

In a chemical reaction the PROPERTIES of the reactants and products are DIFFERENT.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

During a chemical reaction, what happens to atoms?

A

Atoms are rearranged.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why is mass conserved in a reaction?

A

Because all the atoms in the reactants are rearranged into the products.
e.g, all the carbon atoms in all fossil fuels ever burnt are still present but in DIFFERENT forms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How is sulfur dioxide produced?

A

When SOLID YELLOW SULFUR burns. The gas produced (Sulfur Dioxide) is COLOURLESS.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the difference between sulfur and sulfur dioxide in terms of its solubility?

A

Sulfur - Insoluble

Sulfur Dioxide - Dissolves in water to make an acid solution.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What do fossil fuels contain small amounts of?

A

Sulfur from the plants and animals that formed them.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the reaction when sulfur is burned (i.e. fossil fuels)?

A

Sulfur + Oxygen –> Sulfur Dioxide

S + O2 –> SO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What can coal give off more than other fossil fuels?

A

Coal often contains the most sulfur, so burning coal can give off more sulfur dioxide than other fossil fuels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What can sulfur dioxide cause?
Acid rain.
26
What can acid rain do?
It lowers the pH when it falls on land or enclosed water. It can also harm living things. It can erode carbonate rock / limestone (i.e. statues).
27
Is Acid Rain a direct or indirect pollutant?
It does not affect humans directly so it's an INDIRECT pollutant.
28
In detail, how is acid rain caused?
When the sulfur dioxide emitted from vehicle engines/power stations it can react with the MOISTURE within the clouds. This causes DILUTE Sulfuric Acid to be formed.
29
What produces the most pollution? Why?
Power stations and transport. They burn the most fuel.
30
When fuel is burnt, what is ALWAYS formed?
Carbon Dioxide
31
If there is a limited supply of oxygen available, what is this type of combustion called?
INCOMPLETE COMBUSTION
32
What is the reaction of Incomplete Combustion?
Hydrocarbon Fuel + Oxygen (limited) --> Carbon Monoxide/Soot + Water
33
Why is Carbon Monoxide so bad?
It can dissolve into your blood and remove the oxygen within it.
34
Why is solid carbon (soot - particulates) so bad?
It can deposit on surfaces and buildings, making them look dirty.
35
Why must air quality measurements be repeated many times?
Because results vary. On, dry, hot, calm days, air pollutants can be trapped in cities.
36
How is Nitrogen Oxide formed?
In cars, nitrogen and oxygen from the air react at high temperatures. This contributes to acid rain.
37
How is Nitrogen Monoxide (NO) formed?
In furnaces and engines at a temperature of about 1000 C
38
What happens when Nitrogen Monoxide when it is released?
When released into the atmosphere, it COOLS. It then reacts with MORE oxygen to form TOXIC Nitrogen Dioxide, a brown gas (it oxidises).
39
How can we represent the different types of Nitrogen Pollutants? In general, what harm does it cause?
NOx - it can damage buildings, contribute to acid rain and can affect health.
40
State all the molecular formulae of the 6 compounds in this unit.
``` Carbon Dioxide - CO2 Carbon Monoxide - CO Sulfur Dioxide - SO2 Nitrogen Monoxide - NO Nitrogen Dioxide - NO2 Water - H2O ```
41
What are the 4 ways in which Carbon, Sulfur & Nitrogen Oxides and Carbon Dioxide (2) are removed from the air?
1. Particulate Carbon settles on surfaces (making them dirty) 2. Sulfur & Nitrogen Oxides react with water and oxygen to produce a mixture of sulfuric acid and nitric acid in rain (acid rain). 3. Carbon Dioxide is used by plants in photosynthesis. 4. Carbon Dioxide dissolves in rainwater and in oceans.
42
What can climate scientists do, in terms of data, to measure pollutants? Why is this method good?
They can take the MEAN of many measurements for each pollutant. The mean is a good estimate of TRUE VALUE.
43
What is the RANGE?
The difference between high and low results.
44
Why should outliers in pollutant data NOT be removed?
Potential outliers could actually be valid data. | Removing them could lead to mistakes.
45
What are the three ways in which we can reduce the atmospheric pollution made by power stations?
1. Use LESS ELECTRICITY 2. REMOVING sulfur and natural gas and fuel oil. 3. REMOVING Sulfur Dioxide and particulates from the FLUE GASES emitted by coal-burning power stations.
46
Specifically, how can power stations remove solid particulates?
Using ELECTROSTATIC FILTERS.
47
Specifically, how can Sulfur Dioxide be removed from waste gases?
FLUE GAS DESULFURISATION
48
What are the two 'wet scrubbing' alkali methods used to remove sulfur dioxide from power station waste gases?
1. Using an ALKALINE SLURRY of CALCIUM OXIDE (lime) and WATER to make GYPSUM (calcium sulfate). This can be sold as plaster - it's a useful product! :D 2. Using SEAWATER - a natural alkaline which absorbs sulfur dioxide.
49
What is the ONLY way to reduce CO2 emissions?
To reduce the amount of fossil fuels burnt, either by using LESS ELECTRICITY or by finding ALTERNATIVE ENERGY SOURCES.
50
What is a main alternative to fossil fuels?
Biofuel - made from plants (e.g. wood chips, palm oil...)
51
What are biofuels classified as?
'Carbon neutral'. When they are burned the release the SAME amount of CO2 that the plant ORIGINALLY took from the air to grow.
52
What is the slight problem of biofuels?
Large areas of land are required to grow biofuels which can result in species losing their natural habitats. The land could be used to grow food instead...
53
Gas produces _____ CO2 than ____ for the _____ amount of energy released.
Gas produces LESS CO2 than COAL for the SAME amount of energy released.
54
Because fossil fuels are nonrenewable, what are they classified as?
They are NOT SUSTAINABLE.
55
What are the 5 ways in which air pollution from VEHICLES can be reduced?
1. Burning less fuel - i.e. having more efficient engines. 2. Using low-sulfur fuels. 3. Using CATALYTIC CONVERTERS - removes pollutants. 4. Adjusting the balance between public and private transport. 5. Having legal limits to exhaust emissions.
56
What are Catalytic Converters?
These convert HARMFUL Carbon Monoxide and Nitrogen Monoxide into HARMLESS nitrogen and carbon dioxide.
57
What is the chemical reaction within catalytic converters? What is oxidised and what is reduced?
Carbon monoxide + Nitrogen monoxide → Nitrogen + Carbon dioxide Carbon monoxide GAINS oxygen so it is OXIDISED. Nitrogen monoxide LOSES oxygen so it is REDUCED.
58
What is needed in catalysts?
Low sulfur fuels - sulfur can damage the catalysts. | It also reduces sulfur dioxide emissions.
59
What are legal limits for exhaust emissions enforced by?
They're enforced by STRICT MOT TESTS.
60
What are some advantages and disadvantages of electric cars?
+ They do not give out pollutant gases. + Easy to recharge them. - Electricity is still produced (by burning fossil fuels). - There aren't many charging points at the moment. - Batteries and charging times still need to be improved.

Chemistry C123 (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions