# Hard Chemistry Calculation questions anybody? GCSE standard only pls.Watch

Announcements
#1
Hard Chemistry Calculation questions anybody? I've got a test coming up tomorrow on GCSE chemistry calculation questions and please include answers if you have them???
0
9 months ago
#2
Just go through past papers looking specifically for calculation questions - from lots of exam boards, not just your one 0
9 months ago
#3
Moles of Ca(OH)2 in 14.82g. Not sure if this is GCSE, but its easy A-Level stuff so i assume it would be hard GCSE.

0
#4
(Original post by levman2015)
Moles of Ca(OH)2 in 14.82g. Not sure if this is GCSE, but its easy A-Level stuff so i assume it would be hard GCSE.

Thanks-it was ok not too challenging just a simple n = m/Mr
0
9 months ago
#5
0.957mol/dm3 of H2SO4 was neutralised by 858cm3 of 0.642mol/dm3 NaOH. Calculate the volume of H2SO4 neutralised.1) Write the balanced equation. H2SO4 2NaOH → Na2SO4 2H2O2) Calculate the number of mols of NaOH. mol = concentration x volume(divide by 1000 if shown in cm3 to get dm3) =0.642*0.858=0.540564 mols of NaOH present3) Implement ratio/proportion of element. (Numbers in front of substances e.g. 2NaOH denotes 2 mols of NaOH present) NaOH 2SO4 2:1 0.540564/2=0.270282 mols of H2SO4. 4) Calculate volume by using volume = mols/concentration 0.270282/0.957 = 0.2824263323dm3 of H2SO4 used
0
9 months ago
#6
If you really want to challenge, I'd strongly recommend looking at the AS-style questions. What i've seen from the new specification papers is that they're very in lieu of AS-style papers.

Have a look at OCR/AQA AS Papers for the new a level and also old a level specification. (Some questions from the very old a level specification were sampled in the new specimen papers for GCSE).

Obviously, if you see something clearly beyond what you know don't do it - but if you do want "hard" questions, they'll be a good source for you (and also the exam board making the papers). 0
9 months ago
#7
(Original post by Akshi7)
Hard Chemistry Calculation questions anybody? I've got a test coming up tomorrow on GCSE chemistry calculation questions and please include answers if you have them???
0.957mol/dm3 of H2SO4 was neutralised by 858cm3 of 0.642mol/dm3 NaOH. Calculate the volume of H2SO4 neutralised.

1) Write the balanced equation. H2SO4 + 2NaOH → Na2SO4 + 2H2O

2) Calculate the number of mols of NaOH.
mol = concentration x volume(divide by 1000 if shown in cm3 to get dm3)
=0.642*0.858=0.540564 mols of NaOH present

3) Implement ratio/proportion of element. (Numbers in front of substances e.g. 2NaOH denotes 2 mols of NaOH present)
NaOH 2SO4
2:1
0.540564/2=0.270282 mols of H2SO4.

4) Calculate volume by using volume = mols/concentration 0.270282/0.957 = 0.2824263323dm3 of H2SO4 used
0
9 months ago
#8
hiya, i've moved this to chemistry for you 0
#9
Cheers man-guys thanks I think i'm all prepped for tomorrow. Gonna get a good night's sleep and see how it goes!
0
X

new posts
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.

### University open days

• Sheffield Hallam University
Wed, 17 Jul '19
• Regent's University London
Wed, 17 Jul '19
• Norwich University of the Arts
Thu, 18 Jul '19

### Poll

Join the discussion

#### Are you tempted to change your firm university choice now or on A-level results day?

Yes, I'll try and go to a uni higher up the league tables (127)
19.51%
Yes, there is a uni that I prefer and I'll fit in better (62)
9.52%
No I am happy with my course choice (368)
56.53%
I'm using Clearing when I have my exam results (94)
14.44%