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Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>

Is this correct?

1) Find the volume at RTP of 0.2g of Helium gas in cm3

Relative mass of Helium : 4
0.2 / 4 = 0.05
0.05 x 24,000 = 1,200 cm3


2) Find the volume at RTP of 2.0g of CH4 in cm3

Relative mass of CH4 = 16
2 / 16 = 0.125
0.75 x 24,000 = 3,000 cm3



Was completing these questions and the answers don't feel right. Are they correct? If not could someone please guide me to correct working
(edited 7 years ago)
Reply 1
Avatar for alow
alow
19
216≠0.75\dfrac{2}{16} \neq 0.75
Reply 2
Avatar for sammyj97
sammyj97
OP
19
Original post by alow
216≠0.75\dfrac{2}{16} \neq 0.75


Huh?
Reply 3
Avatar for alow
alow
19
Original post by sammyj97
Huh?


Huh?
Original post by sammyj97
1) Find the volume at RTP of 0.2g of Helium gas in cm3

Relative mass of Helium : 4
0.2 / 4 = 0.05
0.05 x 24,000 = 1,200 cm3


2) Find the volume at RTP of 2.0g of CH4 in cm3

Relative mass of CH4 = 16
2 / 16 = 0.75
0.75 x 24,000 = 18,000 cm3



Was completing these questions and the answers don't feel right. Are they correct? If not could someone please guide me to correct working


yep they are correct.
Reply 5
Avatar for alow
alow
19
Original post by Hayley Williams
yep they are correct.


The second one definitely isn't...
Reply 6
Avatar for sammyj97
sammyj97
OP
19
Original post by alow
The second one definitely isn't...


why?
Reply 7
Avatar for alow
alow
19
Original post by sammyj97
why?


216≠0.75\dfrac{2}{16} \neq 0.75
Original post by sammyj97
1) Find the volume at RTP of 0.2g of Helium gas in cm3

Relative mass of Helium : 4
0.2 / 4 = 0.05
0.05 x 24,000 = 1,200 cm3


2) Find the volume at RTP of 2.0g of CH4 in cm3

Relative mass of CH4 = 16
2 / 16 = 0.75
0.75 x 24,000 = 18,000 cm3



Was completing these questions and the answers don't feel right. Are they correct? If not could someone please guide me to correct working


Sorry, wasn't paying attention to the actual numbers, just the method :smile:
2/16 = 0.125
0.125 x 24,000 = 3,000 cm3
Original post by alow
216≠0.75\dfrac{2}{16} \neq 0.75


Why didn't you just give him the correct answer, instead of being annoying? :biggrin::biggrin::biggrin:
Reply 10
Avatar for alow
alow
19
Original post by Hayley Williams
Why didn't you just give him the correct answer, instead of being annoying? :biggrin::biggrin::biggrin:


Because giving someone correct answers rarely accomplishes anything, getting them to think and find the issue with a hint is much more effective.

I don't post here to prove I can do the questions, I do it to help other people figure out the answers by themselves.

Read this: http://www.thestudentroom.co.uk/showthread.php?t=4066671&p=64637319#post64637319
Reply 11
Avatar for sammyj97
sammyj97
OP
19
Original post by alow
Because giving someone correct answers rarely accomplishes anything, getting them to think and find the issue with a hint is much more effective.

I don't post here to prove I can do the questions, I do it to help other people figure out the answers by themselves.

Read this: http://www.thestudentroom.co.uk/showthread.php?t=4066671&p=64637319#post64637319



Her*

Also I appreciate you trying to help but in all honesty your post with the picture made 0 sense to me hence the not replying. I posted all the working out and just wanted confirmation if they were right or wrong.

I'm still unsure if they are or not but i guess i could wait until next week for my tutor.
(edited 7 years ago)
Original post by sammyj97
Her*

Also I appreciate you trying to help but in all honesty your post with the picture made 0 sense to me hence the not replying. I posted all the working out and just wanted confirmation if they were right or wrong.

I'm still unsure if they are or not but i guess i could wait until next week for my tutor.


Your method is correct for both, but on the second one you have the line

"2/16 = 0.75"

that's not true so your final answer ends up wrong!

Just change it so its right and everything is hunky dory :smile:
(edited 7 years ago)
Reply 13
Avatar for alow
alow
19
Original post by sammyj97
Her*

Also I appreciate you trying to help but in all honesty your post with the picture made 0 sense to me hence the not replying. I posted all the working out and just wanted confirmation if they were right or wrong.

I'm still unsure if they are or not but i guess i could wait until next week for my tutor.


Her?

I didn't post a picture...

It's very obvious what I was hinting at.
That = sign with a / means not equal to
Reply 15
Avatar for sammyj97
sammyj97
OP
19
Original post by MexicanKeith
Your method is correct for both, but on the second one you have the line

"2/16 = 0.75"

that's not true so your final answer ends up wrong!

Just change it so its right and everything is hunky dory :smile:


Thank you so much! Just fixed it in my notes
I'm always making silly mistakes by not double checking.

suejiaiuo thanks :smile:
(edited 7 years ago)
Original post by sammyj97
Thank you so much! Just fixed it in my notes
I'm always making silly mistakes by not double checking.


Ahaha, no problem :smile:

That is what alow was trying to tell you, just a bit unfortunate that you haven't come across the "not equal to" sign before! :smile:
hahah

you will need to get used. Alow pointed an error for you, and that's why didn't mention correct. Look back, try more and more, and suddenly you will see yourself getting closer. You need to push yourself out of the box - that's learning.

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