AS Level Chemistry Calculations HELP Watch

richa2798
Badges: 0
Rep:
?
#1
Report Thread starter 4 years ago
#1
Hi, I'm an alevel chemistry student. Ive just started as level chemistry and I'm struggling with the calculations .. such as ideal gas, titration, hydration (calculating the interger of water in an anhydrous compound), molecular formula. My exam board is AQA, specification is Chemistry A.
Please help!!!
Advice, resources and tips will be helpful
0
reply
Tobybeta
Badges: 2
Rep:
?
#2
Report 4 years ago
#2
Hi there!

Chemistry really is about two things:
1) Calculations
2) Processes

The calculations are possibly the easiest to understand, but the toughest to master.

Some are really straight forward once you know them:

Ideal Gas Equation:
PV=nRt

So learn this equation and on every question write it down before you answer it. Rearrange the equation to whatever you are trying to find.
P = Pressure (Pa)
V = Volume (m3)
n = number of moles (if not, use m/Mr)
R = constant (given as 8.31)
t = Temperature (K)
Just solve for the unknown! (If the question is wordy, do what I do with SUVAT in physics and write out all of the values)
Titration
This one requires two equations: c=n/v (v in dm3) AND n=m/Mr
If you learn these, just write out the values you know and find the ones you don't. When doing this, find the molar ratio by writing out the balanced equation.

We haven't done hydration yet, so I'll pass on that

Molecular Formula
I assume here we're talking about empirical to molecular? If so, just find Mr of the molecule, and Mr of the empirical and then multiply the numbers in subscript in the empirical formula by the number you just calculated.

Just learn the equations and really practise. Hope this helps, and if you have any more problems just let me know.
1
reply
richa2798
Badges: 0
Rep:
?
#3
Report Thread starter 4 years ago
#3
(Original post by Tobybeta)
Hi there!

Chemistry really is about two things:
1) Calculations
2) Processes

The calculations are possibly the easiest to understand, but the toughest to master.

Some are really straight forward once you know them:

Ideal Gas Equation:
PV=nRt

So learn this equation and on every question write it down before you answer it. Rearrange the equation to whatever you are trying to find.
P = Pressure (Pa)
V = Volume (m3)
n = number of moles (if not, use m/Mr)
R = constant (given as 8.31)
t = Temperature (K)
Just solve for the unknown! (If the question is wordy, do what I do with SUVAT in physics and write out all of the values)
Titration
This one requires two equations: c=n/v (v in dm3) AND n=m/Mr
If you learn these, just write out the values you know and find the ones you don't. When doing this, find the molar ratio by writing out the balanced equation.

We haven't done hydration yet, so I'll pass on that

Molecular Formula
I assume here we're talking about empirical to molecular? If so, just find Mr of the molecule, and Mr of the empirical and then multiply the numbers in subscript in the empirical formula by the number you just calculated.

Just learn the equations and really practise. Hope this helps, and if you have any more problems just let me know.
Thank You soo much!!! Great HELP
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Latest
My Feed

See more of what you like on
The Student Room

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

Personalise

University open days

  • Bournemouth University
    Clearing Open Day Undergraduate
    Wed, 31 Jul '19
  • Staffordshire University
    Postgraduate open event - Stoke-on-Trent campus Postgraduate
    Wed, 7 Aug '19
  • University of Derby
    Foundation Open Event Further education
    Wed, 7 Aug '19

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 (132)
18.7%
Yes, there is a uni that I prefer and I'll fit in better (71)
10.06%
No I am happy with my course choice (402)
56.94%
I'm using Clearing when I have my exam results (101)
14.31%

Watched Threads

View All