Chemistry OCR F323 Quantitative Task help needed

Hello, I have a practical exam on Thursday and we have been given the title of 'finding the formula of a hydrated salt' . How can I prepare for this (aside from actually doing the practical? What saftey precautions will I have to take? Would there be any issues with accuracy? Thank you!

Reply 1

She-Ra

Universities Forum Helper

21

Original post by Phoebe_Squire

Hello, I have a practical exam on Thursday and we have been given the title of 'finding the formula of a hydrated salt' . How can I prepare for this (aside from actually doing the practical? What saftey precautions will I have to take? Would there be any issues with accuracy? Thank you!

Moved this to Chemistry exams for you :smile:

Reply 2

Lau14

11

Original post by Phoebe_Squire

Hello, I have a practical exam on Thursday and we have been given the title of 'finding the formula of a hydrated salt' . How can I prepare for this (aside from actually doing the practical? What saftey precautions will I have to take? Would there be any issues with accuracy? Thank you!

Practice finding the number of waters of crystallisation for the formula - doing practice questions on it out of the textbook would probably be useful if it's something you need work on? There will be a small written/question part to the paper and judging by the title they will likely ask you to calculate these.

Safety precautions should be detailed in the instructions section of the practical, but depending on the chemical they are unlikely to be more than wear safety glasses, do not ingest chemicals, and safe use of bunsen burners.

There may be a few marks for accuracy (there usually is). I don't know how wide the error margin is for this, but as long as you try and follow the instructions carefully you shouldn't have a problem.

Hope this helps! Good luck :smile:

Reply 3

josiejump123

1

hey phoebe fancy seeing you here

Reply 4

adam-mariam

Can you please tell me how it goes as I'm doing it in april and please please if you could remember what kind of questions they'll give you let me know and thank you

Reply 5

byakuya99

1

Hey phoebe, I'm scared about this one could you please help me out with the questions :wink:

, from one chemistry survivor -I meant student- to another. I'm totally freaking out :s-smilie:

.

Reply 6

josiejump123

1

remember the basic formulae for :amounts
n=m/Mr
:tongue:

ercentage error
percentage error=max error/measured value x 100

-just simply taking care to get the right Mr and not making mistakes
-degree of accuracy (3sf/2dp just whatever the paper specifies)
-right units
-averages and remembering to use the actual average when asked for not a rounded one to 3sf/2dp
-ratios; especially when working out empirical formula
-using your initiative with safety
-if you get stuck just think about it logically

snm really but you'll be fine

Reply 7

Phoebe_Squire

OP

1

Original post by byakuya99

Hey phoebe, I'm scared about this one could you please help me out with the questions :wink:

, from one chemistry survivor -I meant student- to another. I'm totally freaking out :s-smilie:

.

Hello , I hope this isn't too late. I unfortunately cant tell you the questions or answers as that would be cheating. But you should keep a couple of things in mind:-read everything extra carefully (they give a formula, which basically alters what your answer will be at the end)
-think about mole ratio
-practice finding what metal is in a hydrated salt, and practice finding the amount of moles of water
-don't panic and it should be pretty easy
-at the end check everything , and see if your answer makes sense

Reply 8

Phoebe_Squire

OP

1

Also, everything Josie said here will be of help too. Good Luck!

Reply 9

Phoebe_Squire

OP

1

Oh, percentage mass too

Reply 10

byakuya99

1

Thanks a lot phoebe!!! :biggrin:

Reply 11

byakuya99

1

Original post by Phoebe_Squire

Hello, I have a practical exam on Thursday and we have been given the title of 'finding the formula of a hydrated salt' . How can I prepare for this (aside from actually doing the practical? What saftey precautions will I have to take? Would there be any issues with accuracy? Thank you!

BTW phoebe is this the OCR A or OCR B (salters?)

Reply 12

stardust22

1

I know this is a bit late but it may prove to be helpful to others :smile:

Things you should practice:
1)Converting mass into moles
2) Percentage by mass of water present in the crystals
3) Ions involved in the salt
4) Equation if the hydrated salt is heated
6)Using the equation to identify the moles of anhydrous salt.
There is a really good worked example in the OCR textbook.
Make sure you have your answer to 3 significant figures, if it is not specified in the questions and manage your time properly! Good luck :biggrin:

Reply 13

RIDDHI7

2

Has anyone done the quqalititve on salts

Reply 14

RIDDHI7

2

Original post by stardust22

I know this is a bit late but it may prove to be helpful to others :smile:

Things you should practice:
1)Converting mass into moles
2) Percentage by mass of water present in the crystals
3) Ions involved in the salt
4) Equation if the hydrated salt is heated
6)Using the equation to identify the moles of anhydrous salt.
There is a really good worked example in the OCR textbook.
Make sure you have your answer to 3 significant figures, if it is not specified in the questions and manage your time properly! Good luck :biggrin:

Hi is this for ocr. what other topics should i revise. this is my last re-take plz help.