Yoo hoo i need help Mr sadako or any one!!!

[GRIM_REAPER]

Now i think im rite in saying that you are chemist of some kind or have i been diluded all this time? any how any will do heres me problem:
Im doing my bio coursework and investigation into the water potential of potato and parsnip, now thats all fine there just one bit i need help on.
i need to convert some percentage concentrations into molar mass so heres the info i think you'll need:

Were using Sucrose solution which started at 20% conc
From that we made up : 0.5%, 1%, 10%, and used 20% but how do i get this inot molar??

ANy help is appriciated any mor einfo needed just ask:)

GRIM AKA a struggling Paul

[Dr Sadako]

You are right on track. I got a M.Sc. in chemical engineering and right now I have 10 months left to my PhD in inorganic chemistry (materials chemistry and nanotechnology).

Sucrose is glucose+fructose i.e. (C6H11O5)O(C6H11O5)

M = Molar mass (sucrose) = 12 x 12.011 + 22 x 1.0079 + 11 x 15.9994 g/mole = 342.2992 g/mole

20% sucrose concentration means 20 weight percent. If you have 1 litre of water it weighs 1000g (if we presume that the density is 1 g/cm3). This would mean that we have 200 g sucrose solved in the water if we have a 20% solution. We can now calculate how many moles of sucrose we have.

n (Sucrose) =  m (sucrose) / M (sucrose) = 200 g / 342.2992 g/mole = 0.5842 mole

Then we immmediatly get that the concentration is 0.5842 mole/litre in the 20% solution.


I think you will manage to solve (no pun intended) the other percentages yourself.

[TeaLeaf]

This lecture will be repeated on BBC2 at 7.00pm for those who missed the early morning broadcast :lol:

w2g Sadako, I couldn't have put it better myself.  No, really, I *couldn't*.

TL.

[Anonymous]

Nope, I couldn't have put that any better either

However, my degree is in Astrophysics and I do know that if you run at 0.866 the speed of light you can (momentarily) fit a 20 foot pole into a 10 foot garage due to Lorentz Contraction.

This exercise will be closely followed by a huge explosion as all the stored energy is released at once :devil:

Hope this helps

[Doorman]

Originally posted by Sadako@Mar 17 2004, 08:11 AM
You are right on track. I got a M.Sc. in chemical engineering and right now I have 10 months left to my PhD in inorganic chemistry (materials chemistry and nanotechnology).

Sucrose is glucose+fructose i.e. (C6H11O5)O(C6H11O5)

M = Molar mass (sucrose) = 12 x 12.011 + 22 x 1.0079 + 11 x 15.9994 g/mole = 342.2992 g/mole

20% sucrose concentration means 20 weight percent. If you have 1 litre of water it weighs 1000g (if we presume that the density is 1 g/cm3). This would mean that we have 200 g sucrose solved in the water if we have a 20% solution. We can now calculate how many moles of sucrose we have.

n (Sucrose) =  m (sucrose) / M (sucrose) = 200 g / 342.2992 g/mole = 0.5842 mole

Then we immmediatly get that the concentration is 0.5842 mole/litre in the 20% solution.


I think you will manage to solve (no pun intended) the other percentages yourself.

 I was gonna say that.

[Anonymous]

Stop following me round the forums Ron I'm getting a complex  :narnar:

[Dr Sadako]

Originally posted by BlueBall@Mar 17 2004, 10:00 AM
Nope, I couldn't have put that any better either

However, my degree is in Astrophysics and I do know that if you run at 0.866 the speed of light you can (momentarily) fit a 20 foot pole into a 10 foot garage due to Lorentz Contraction.

This exercise will be closely followed by a huge explosion as all the stored energy is released at once :devil:

Hope this helps

And for those of you who don't know about the special theory of relativity:

http://www.fourmilab.ch/cship/lorentz.html

[Anonymous]

Nice site Sadako. I've bookmarked it for future reference (homework etc)

[Doorman]

Originally posted by BlueBall@Mar 17 2004, 09:04 AM
Stop following me round the forums Ron I'm getting a complex  :narnar:

Getting?

[GRIM_REAPER]

wow thanks alot sadako im off to finnish me write up now

[Zok]

Originally posted by GRIM_REAPER@Mar 17 2004, 10:42 AM
wow thanks alot sadako im off to finnish me write up now

I think you'll find he's Swedish

[Anonymous]

Oh ffs Zok that was truly bad.

Well done m8

[DuVeL]

:learn: Hey Mats, you know how to calculate buildingconstructions aswell? You can make a test for me then.   BTW, I almost had the same answer.

[Anonymous]

Originally posted by DuVeL@Mar 17 2004, 12:11 PM
:learn: Hey Mats, you know how to calculate buildingconstructions aswell? You can make a test for me then.   BTW, I almost had the same answer.

1 building construction + 1 building construction = 2 building constructions

Easy peasey

[GRIM_REAPER]

just to check im on the right track or am i compleatly wrong to get that mole's per litre into the 10% equivelent do i just need to half it or is it not that simple?