Notesale: Turn your study into money

Document Preview

Extracts from the notes are below, to see the PDF you'll receive please use the links above

---

UNIT 14 - ASSIGNMENT 2 - P2 - TASK 1 BOYLE’S LAW
INVESTIGATION
Objectives:
You will carry out an investigation into the relationship between pressure and volume for a fixed
mass of gas
...


Equipment:
•
•
•
•

Air pump
Bourdon gauge
Oil reservoir
Oil

•

Strong glass tube

Method:
1
...
Record the volume reading at this
setting
...
Increase the pressure by 20 kNm-3 and record the new volume
...
Repeat until you have reached a pressure of 340 kNm-3
...
Calculate the valve of 1/V and record in the table
...
Calculate pressure * volume (pv) and record in the table)
...
Plot a graph of p against v and another of p against 1/V
...
Write conclusions commenting on your results and graphs
...
846
18
14
...
052
9
...
826
6
...
6
4
...
193
3
...
285
2
...
This graph shows that pressure is
indirectly proportional to volume, as when the volume increases, the pressure decreases
...
This may be due to some of the
errors that can take place such as parallax error
...


Due to the positive correlation, this graph shows that as the 1/Volume increases, the pressure
increases
...
My graph look similar to the graph
above that, although there is a number of 'odd' points; they are not on the line of best fit - especially
the last point plotted at (23
...
This could be due to the error when calculating the value for
1/volume; if someone were to use the wrong formula or type the calculation wrong in the calculator,
this would cause the reading to be wrong
...


Boyle's law
Boyle's law states that: "For a fixed mass of gas at constant temperature, the volume is inversely
proportional to the pressure
...


High pressure cylinders VS atmospheric cylinders
When in a hospital, there are an number of pros and cons when using high pressure cylinders to
supply oxygen rather than in atmospheric cylinders
...
By doing so, you could store more
cylinders in an area
...

Less transport is needed than the atmospheric cylinders, so that there will be lesser journeys
to get the high pressure cylinders from place to place
...

The high pressure cylinders will last longer than the atmospheric cylinders and will not need
as much maintenance to replace them; therefore there would be a decrease in maintenance
fees, resulting in a bigger profit/income
...

There may be more sales and distributions due to the efficiency of the high pressure
cylinder, resulting in a bigger profit/income
...
This may
result in a smaller profit/income due to the higher fee
...

Each high pressure cylinder will be heavier, which means maintenance could possibly cost
more
...

If the cylinder would somehow explode, the high pressure cylinder will cause more damage
than the atmospheric cylinder
...
This may lead to a smaller profit/income
...
However, the volume of
the cylinder stays the same
...


Plastic bottle
On the ground

When on the ground, the pressure inside the bottle is equal to the pressure outside the
bottle
...


In the air - before opening

P↓ ↓PV↓ constant
When in the air, before opening, the pressure inside the bottle is greater to the pressure
outside the bottle
...
The volume may increase if the bottle is not strong
...
If not, the bottle may still expand
...


After opening

After opening, the pressure inside the bottle then equalises and becomes the same as the
pressure outside the bottle
...


Close bottle - return to ground

When closing the bottle and returned to ground, the pressure on the outside is greater than
the pressure on the inside
...
This is due to the high pressure atmosphere
...

1) P1 and P2= Constant
T1 = 20oC = 293K
T2 = ?
V1= 1m3
V2 = 2m3

(P1V1) / T1 = (P2V2) / T2
V1 / T1 = V2 / T2
(T1 * V2) / V1 = T2
(293 *2) / 1 = 586 K- 273 = 313oC
T2 = 313oC

2) P1 = 2
...
7 / 270) * 300 = 3
P2 = 3 Atmospheres

3) P1 = 1 atmosphere
P2 = 1
...
4 * 373) / 1 = 533
...
045
V2 = 0
...
9kPa
As the pressure is 1071
...


6) P1 = 2
...
5 / 293) * 303 = 2
...
585 Atmospheres

7) P1 = 100kPa
P2 = 40kPa
V1 = 6m3
V2 = ?

T1 = Constant
T2 = Constant

(P1V1) / T1 = (P2V2) / T2
P1V1 = P2V2
(P1V1) / P2 = V2
(100 * 6) / 40 = 15m3
V2 =15m3

8) P1 = 1 Atmosphere
P2 = ?
V1 = 60cm3
V2 = 15cm3
T1 = 17oC = 290K
T2 = 27oC = 300K

(P1V1) / T1 = (P2V2) / T2
((P1V1) / (T1V2)) * T2 = P2
((1 * 60) / (290 * 15)) * 300 = 4
...
137 Atmospheres

9) P1 = 1 Atmospheres
P2 = 4 Atmospheres
V1 = 300cm3
V2 = 200cm3
T1 = 300k
T2 = ?

(P1V1) / T1 = (P2V2) / T2
T2 = (P2 * V2 * T1) / (P1V1)
= (4 * 200 * 300) / (1 * 300) = 800K - 273

= 527OC

10) P = 2,000,000
V = 0
...
313mol-1K-1
PV = nRT
n = (PV) / (RT)
= (2,000,000 * 0
...
313 * 293) = 82
...
14 = 2628
...
63kg

UNIT 14 - ASSIGNMENT 2 -D1
Diesel engines
The diesel internal combustion engine differs uses a high compression of hot air to light the fuel
instead of a spark plug ignition
...
The air is then
compressed with a compression ratio typically between 15:1 and 22:1 compared to in a petrol
engine; this high compression heats the air to 550 °C
...
This may be into a
void in the top of the piston or a pre-chamber depending how the engine is designed
...

The heat of the compressed air vaporises fuel from the surface of the droplets
...
This stops when all the fuel in the
droplets has been burnt off
...
The fast expansion of the
combustion gases later drives the piston down; this supplies power to the crankshaft
...

As well as the high level of compression allowing combustion to take place without a separate
ignition system, a high compression ratio greatly increases the engine’s efficiency
...
Since only air is compressed in a
diesel engine and fuel is not put into the cylinder until shortly before the top dead centre
...


Turbines
The electrical energy produces at a power station is a very convenient from of energy
...

A thermal power station uses coal, oil, natural gases in the atmosphere or uranium as the main
energy source
...
However in a
nuclear power station, CO2 is heated by the fission of uranium in a nuclear reactor
...
The steam passes through pipes to the high-pressure cylinder of a steam turbine
...
These direct the steam on to a second ring of
blades, which are secured to the turbine shaft; these turn under the force of the steam
...
When it
leaves the high-pressure cylinder, the steam returns to the boiler/heat exchanger to reheat; after
that, it enters the intermediate and low pressure cylinders
...
Because of this expansion, the blades are
much larger towards the low-pressure end of the turbine
...
A partial vacuum is created
in the condenser, (this is due to the greater density of the water) this increases the efficiency of the
process and allows more energy to be extracted from the steam
...
After the water is used, it is cooled down in a large cooling tower (and
then of course, reused again)
...
As the steam's temperature
increases, the volume increases
...
Also, there is more kinetic energy moving the particles around
...

However, the mass is constant as it is the same amount of water, just in different volumes
...
" This means that when you double the pressure, the volume will halve
...
" That means that if you double the temperature in kelvin at
constant pressure, the volume of a fixed mass of the gas will also double
...

This is because the gas can expand when heated or be compressed (like in a high-pressure cylinder)
...
A gas particle is
constantly moving around until they collide with another particle
...
When molecules collide the total kinetic energy is conserved
...
The molecules will become
stationary is the temperature is 0 degrees
...
As the speed of
the particles travel faster, this increases the chance of it colliding with another
...
If a gas is
compressed to a smaller volume, this will increase the chance of collision whilst the pressure also
increases
...


b) The fizzy drink industry uses gas pressure to make drinks fizz when a can/bottle is opened
...
The additional pressure at the surface of the liquid inside the bottle
forces the bubbles to stay dissolved within the drink
...
The loud hiss noise that
is made is the pressure difference equalising itself
...
This carries on until the pressure inside the bottle is
equal to the pressure outside the can/bottle
...

Nevertheless, once this action occurs, the pressure inside the bottle is a lot lower
...
The bubbles then burst at a fast rate
when they reach the surface
...
The only gas that is still
dissolved in the liquid is held back by the relatively weak atmospheric pressure
...

Pressurization becomes necessary at altitudes above 12,500 feet to 14,000 feet to protect the
flight/cabin crew and passengers
...

Hypoxia - The lower pressure of oxygen at a high altitude decreases the alveolar oxygen tension in
the lungs and in the brain
...
Some people's symptoms may begin as low as around 5,000 feet (especially those
with those who suffer from lung or heart disease
...
There is around 25% less oxygen in the atmosphere at this altitude
...
However,
without pressurization, the oxygen can be given up to an altitude of 40,000 feet
...
This
partial oxygen pressure is required to function normally and stay up to 40,000 feet by increasing the
moles of oxygen in the air, which is being breathed
...
2 bar
and to keep a minimum pressure of oxygen of 0
...
Emergency oxygen supply masks do not need to be pressure-demand
masks
...
Above that altitude the pressure of oxygen
falls below 0
...

Decompression sickness - The low partial pressure of gases may cause dissolved gases in the
bloodstream to precipitate out
...
This may
include symptoms such as: tiredness, forgetfulness, headache, stroke, thrombosis, and
subcutaneous itching
...

Altitude sickness - Hyperventilation is the most common response to hypoxia, does help to partially
restore the pressure of oxygen in the blood
...
Passengers may experience fatigue, nausea,
headaches, sleeplessness and even pulmonary oedema (on longer flights)
...
However pulmonary oedema is unlikely
...
This covers the body completely in
a pressurized environment; this is not used for passengers
...
As the aircrafts' altitude, passengers may experience discomfort or acute pain as gases
trapped within their bodies expand or contract
...
Pain may also be felt in the gastrointestinal tract or even the teeth
...
It can also
worsen existing medical conditions like pneumothorax
...


Bibliography:
•

http://www
...
co
...
html



---