# Unit 14 D2 HELP! BTEC LEVEL 3 SCIENCE

Watch
Announcements
#1
Can anyone explain gas pressure and how it affects industrial processes?
0
3 years ago
#2
Nimmsss

HI,
Let me make this easy peasy lemon squeezy for you (sorry but you are probs a baby compared to some of us haha )

Pressure affects the volume of a gas. Boyles Law states that the volume of a gas is inversely proportional to the pressure exerted on it at constant temperature (why is constant temp a condition?? - yes, well done! - cos temp also has an effect on volume of gas [remember Charles' Law?)

So, it is conceivable that if you press a gas like (sort of by increasing pressure), you can imagine the volume will reduce - like compressing a flexible piece of rubber (just to explain) - the harder you press a soft elastic ball (e.g.) the smaller it will become, agreed?

Ok, now let us take chemical reactions:-

e.g. to make ammonia (Haber process?? - sorry I did my A level chemistry 15 years ago - now you can guess how much (actually how little!) hair I have on my head ), you react hydrogen with nitrogen.

3H2 + N2 ---> 2NH3

By Avogadro's rule, there are 4 moles (therefore 4 volumes) of gas on left of equation [3 + 1] and 2 volumes on right - yeah?

so from left to right, we are reducing total volume of gas - makes sense? OK good! So you can imagine Going back to Boyles Law above, that because higher pressure makes volume smaller (remember like compression?), so higher pressure will drive this equation to the right i.e. more ammonia gas (NH3) [less volume = 2 moles] will be produced rather than reversed equation (breakdown of ammonia into N2 and H2)[more volume = 4 moles].

Conversely (= other way round) In a reaction where volume increases to the right, you will need to use low pressure to drive the equation.

I hope this helps.

M (Specialist biology tutor)
1
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### Poll

Join the discussion

#### What are you most likely to do if you don't get the grades you were expecting?

Go through Clearing (189)
38.73%
Take autumn exams (149)
30.53%
Look for a job (17)
3.48%
Consider an apprenticeship (21)
4.3%
Take a year out (84)
17.21%
Something else (let us know in the thread!) (28)
5.74%