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# Help with moles watch

1. How do I solve this:
1.Find the mass of 120 cubic cm of chlorine
2.Find the volume of 0.1 moles of fluorine
3.How many moles are in 2000 cubic cm and 2 mol cubic dm of NaCl (aq)
I need all the help I can get!! I really don't understand moles!

2. where did you get these questions from?
3. (Original post by IkraShahid786)
where did you get these questions from?
Its homework!! Our teacher gave it to us...why do you ask? Are they extremely easy?
4. (Original post by kinji)
Its homework!! Our teacher gave it to us...why do you ask? Are they extremely easy?
no they're not that easy... but i've never come across such questions thats why... let me see what i can work out and will let you know asap
5. (Original post by IkraShahid786)
no they're not that easy... but i've never come across such questions thats why... let me see what i can work out and will let you know asap
Thanks so much! I've been struggling with them since ages...
6. as much as i know, i've come up with these answers
for Q1 - you cant work out the mass because you've only got the volume
(you don't have the moles or the concentration)

for Q2 - you can't find the volume because you don't have the concentration
(remember the formula: volume = moles / concentration )

for Q3 - to work out the moles, you need to use this formula:
concentration = moles / volume
and so when you rearrange this to find moles, you're formula should look like this: moles = concentration x volume

so,
(to convert cm cubed into dm cubed we have to divide by 1000)

(2000/1000) x 2 = 4 moles

hope this helps*
7. Check them regularly and make sure you seek advice if they change colour or shape suddenly . . .
8. (Original post by IkraShahid786)
as much as i know, i've come up with these answers
for Q1 - you cant work out the mass because you've only got the volume
(you don't have the moles or the concentration)

for Q2 - you can't find the volume because you don't have the concentration
(remember the formula: volume = moles / concentration )

for Q3 - to work out the moles, you need to use this formula:
concentration = moles / volume
and so when you rearrange this to find moles, you're formula should look like this: moles = concentration x volume

so,
(to convert cm cubed into dm cubed we have to divide by 1000)

(2000/1000) x 2 = 4 moles

hope this helps*
Thanks a ton!!
9. (Original post by Palatial Veranda)
Check them regularly and make sure you seek advice if they change colour or shape suddenly . . .
What??????
OMG. We were talking about the chemical version of moles not those on the skin...
10. (Original post by kinji)
Thanks a ton!!
no problem

mole questions arent that hard, just remember 2 things:
- the formula's
- conversions (cm3 into dm3 ect..)
11. (Original post by kinji)
What??????
OMG. We were talking about the chemical version of moles not those on the skin...
Oh really. Sorry. It's not like I was being irreverent or tongue-in-cheek or anything . . .
12. (Original post by Palatial Veranda)
Oh really. Sorry. It's not like I was being irreverent or tongue-in-cheek or anything . . .
Its fine. No worries
13. (Original post by IkraShahid786)
no problem

mole questions arent that hard, just remember 2 things:
- the formula's
- conversions (cm3 into dm3 ect..)
I'll try...I have two more pages of these to solve! I need divine intervention now but anyways, thanks a lot!!
14. (Original post by kinji)
I'll try...I have two more pages of these to solve! I need divine intervention now but anyways, thanks a lot!!
i can help with any other questions you might have problems with so don't hesitate to post another one or more

(here to help)
15. (Original post by kinji)
How do I solve this:
1.Find the mass of 120 cubic cm of chlorine
2.Find the volume of 0.1 moles of fluorine
3.How many moles are in 2000 cubic cm and 2 mol cubic dm of NaCl (aq)
I need all the help I can get!! I really don't understand moles!
(Original post by IkraShahid786)
as much as i know, i've come up with these answers
for Q1 - you cant work out the mass because you've only got the volume
(you don't have the moles or the concentration)

for Q2 - you can't find the volume because you don't have the concentration
(remember the formula: volume = moles / concentration )

for Q3 - to work out the moles, you need to use this formula:
concentration = moles / volume
and so when you rearrange this to find moles, you're formula should look like this: moles = concentration x volume

so,
(to convert cm cubed into dm cubed we have to divide by 1000)

(2000/1000) x 2 = 4 moles

hope this helps*
I imagine kinji is using the assumption of 1 mole of any gas occupies 24dm3 under standard conditions if it's school level questions.
Moles * 24 = volume of gas (dm3) is your equation to use to find out the first two.
16. (Original post by Spoogle)
I imagine kinji is using the assumption of 1 mole of any gas occupies 24dm3 under standard conditions if it's school level questions.
Moles * 24 = volume of gas (dm3) is your equation to use to find out the first two.
Thanks for that!

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