You are Here: Home

# Calculating X - Moles watch

1. I don't understand the part where it says moles of cl2 is half that of cl, i've highlighted what I'm confused on, thanks
Attached Images

2. (Original post by raiden95)
I don't understand the part where it says moles of cl2 is half that of cl, i've highlighted what I'm confused on, thanks
you have found that there are 0.06 moles of chloride ion (Cl- ). A group two chloride has a formula of MCl2 - meaning it has two chloride ions. So your moles of MCl2 must be half the moles of chloride, ie 0.03

To put it another way, each mole of metal chloride contains 2 chloride ions. So if you have a total of 0.06 moles of chloride ions, you must have 0.03 moles of metal chloride.

ok?
3. (Original post by Plato's Trousers)
you have found that there are 0.06 moles of chloride ion (Cl- ). A group two chloride has a formula of MCl2 - meaning it has two chloride ions. So your moles of MCl2 must be half the moles of chloride, ie 0.03

To put it another way, each mole of metal chloride contains 2 chloride ions. So if you have a total of 0.06 moles of chloride ions, you must have 0.03 moles of metal chloride.

ok?
So two chloride ions means less moles, thats confusing
4. (Original post by raiden95)
So two chloride ions means less moles, thats confusing
how is it confusing? A car needs four tyres. If I have eight tyres, how many cars can I equip? Fewer cars than eight. Obvious, surely?
5. If you don't mind me asking, which app are you using?
6. (Original post by zed963)
If you don't mind me asking, which app are you using?
7. (Original post by Plato's Trousers)
you have found that there are 0.06 moles of chloride ion (Cl- ). A group two chloride has a formula of MCl2 - meaning it has two chloride ions. So your moles of MCl2 must be half the moles of chloride, ie 0.03

To put it another way, each mole of metal chloride contains 2 chloride ions. So if you have a total of 0.06 moles of chloride ions, you must have 0.03 moles of metal chloride.

ok?
but Cl- is one ion so if I'm looking for MCl2 then wouldn't I want to times 0.06 by 2 rather than divide it? I know I'm wrong but do you know where I'm coming from?
8. (Original post by raiden95)
Damn!
9. (Original post by raiden95)
So two chloride ions means less moles, thats confusing

(Original post by Alia223)
but Cl- is one ion so if I'm looking for MCl2 then wouldn't I want to times 0.06 by 2 rather than divide it? I know I'm wrong but do you know where I'm coming from?
You know you have 0.06 moles of chloride. How many moles of MCl2 can you make from that? Half as many - because each MCl2 needs two chlorides.

Is this any clearer?
Attached Images

10. (Original post by zed963)
Damn!
A very neat app for organising
Attached Images

11. (Original post by Plato's Trousers)
You know you have 0.06 moles of chloride. How many moles of MCl2 can you make from that? Half as many - because each MCl2 needs two chlorides.

Is this any clearer?
OK I get the diagram, now can you help me understand the question using that diagram please!! =/
12. (Original post by Plato's Trousers)
You know you have 0.06 moles of chloride. How many moles of MCl2 can you make from that? Half as many - because each MCl2 needs two chlorides.

Is this any clearer?
This is starting to make sense! Thanks
13. (Original post by Alia223)
OK I get the diagram, now can you help me understand the question using that diagram please!! =/
ok, so you were asked to calculate how many moles of chloride you had. You found there were 0.06 moles of chloride ions. Do you agree?

These chloride ions came from dissolving a group 2 metal chloride. Agreed?

The forumula of a group 2 metal chloride is MCl2. Agreed?

So each mole of metal chloride will produce two moles of chloride ions. Agreed?

Therefore you must have had 0.03 moles of the metal chloride to start with (because 0.03 times 2 is 0.06). Agreed?
14. (Original post by raiden95)
A very neat app for organising
Are there any apps for an iPhone? Is it worth investing in an iPad for sixth form or shall I just get a normal laptop?
15. (Original post by zed963)
Are there any apps for an iPhone? Is it worth investing in an iPad for sixth form or shall I just get a normal laptop?
I have not used a laptop in a very long time, my ipad is very useful also saves a lot more time, easier to screenshot and save etc also takes up very little space, its your call

I don't think this app is available on iphone because of the screen size
16. (Original post by Plato's Trousers)
ok, so you were asked to calculate how many moles of chloride you had. You found there were 0.06 moles of chloride ions. Do you agree?

These chloride ions came from dissolving a group 2 metal chloride. Agreed?

The forumula of a group 2 metal chloride is MCl2. Agreed?

So each mole of metal chloride will produce two moles of chloride ions. Agreed?

Therefore you must have had 0.03 moles of the metal chloride to start with (because 0.03 times 2 is 0.06). Agreed?
Wow you're amazing, thank you!!!
17. (Original post by zed963)
Are there any apps for an iPhone? Is it worth investing in an iPad for sixth form or shall I just get a normal laptop?

(Original post by raiden95)
I have not used a laptop in a very long time, my ipad is very useful also saves a lot more time, easier to screenshot and save etc also takes up very little space, its your call

I don't think this app is available on iphone because of the screen size

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: January 4, 2013
Today on TSR

### Edexcel GCSE Maths Unofficial Markscheme

Find out how you've done here

### AQA Maths Paper 1 exam discussion

Poll

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE