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# Chemistry HELP NEEDED AS LEVEL!

hiya, have a h/w question can anyone help ?
Calculate number of moles of HCL in 75.0cm cubed of 0.500mol dm-3
Hydrochloride acid?

HCl is Hydrochloric acid

i done this, this year, year 11.

you have to get ar number and divide

Original Poster

strike;3401107

i done this, this year, year 11.you have to get ar number and divide

im trying but u need the mass and its not given ?

Original Poster

Banned

e.g. Calculate the number of moles in :

i) 1x 10^20 molecules of ammonia

ii) 1 million molecules of water

jus divide those numbers by avagadros number [6.02 x 10^23]

1000/75 = 13.33333

1 mol of HCL is 36.46g/mol

.5 mol of HCL is therefor 18.23g/dm3

you have 75cm cubed, so divide by 13.333333 = 1.367g

1.367/36.46 = 0.0375 mol, or 3.75x10^-2 mol

DEFINATELY get a second oppinion, as that could be utter ****

BFM

Original Poster

GOT IT GUYS its 0.0375 mol for deffo :thumbsup:

Thanks for helpo

Can't believe i was right, been 7 or so years since i last used anything to do with that lol!

BFM

Reminds me of my very first A-level lecture.
It gets better from here!

Original Poster

7 YEARS would never remember it after that long (trust me im ****) but told u get better so we will see...

Carbon chemistry FTW

BFM

Original Poster

If anyone wants to help with anymore questions just ask lol got a ton ... lol but im doing them ok i just want to check my answers. (Hopes chemistry teacher is not looking at site :P)

Trust me if there's something you don't understand, pester the lecturer to explain it until it clicks, they'll appreciate the fact that you show interest and in the long run you'll benefit because the basics will help you understand more and more as your course progresses.

a level chemistry....good times! seriously my fave a level..... didnt click till year 13 what was happening but when it did i was like yeaaaaaah bwoy!

Original Poster

bargain surfer;3401702

Trust me if there's something you don't understand, pester the lecturer … Trust me if there's something you don't understand, pester the lecturer to explain it until it clicks, they'll appreciate the fact that you show interest and in the long run you'll benefit because the basics will help you understand more and more as your course progresses.

Will bear this is mind :whistling: (ANNOY TEACHER LOL) easily done :thumbsup:

Chesso I would think is your best bet for advice on this ?

Banned

if your doind aqa, you can get 100% in the exam by just doing (includes marking and then learning from the questions you got wrong) on past papers.

is chemistry a good a level.My physics teacher said it is just advanced chemistry.

Im good at chemistry.

What can you do at degree if you got a level in chem.