Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: thegers91 on 19/04/2009 16:21:35

Title: How do I calculate the amount of ethanol in a bottle of 12.5% strength wine?
Post by: thegers91 on 19/04/2009 16:21:35

hi there, been doing a chemistry investigation in to the ethanol in wine.

i have a result for the ethanol content in moll-1

but im struggling to calculate what the average amount of ethanol in 12.5% 750 ml bottle to compare my result

any help into getting an answer would be greatly appreciated

Title: Re: How do I calculate the amount of ethanol in a bottle of 12.5% strength wine?
Post by: lightarrow on 19/04/2009 16:35:55

Quote from: thegers91 on 19/04/2009 16:21:35

hi there, been doing a chemistry investigation in to the ethanol in wine.

i have a result for the ethanol content in moll-1

but im struggling to calculate what the average amount of ethanol in 12.5% 750 ml bottle to compare my result

any help into getting an answer would be greatly appreciated

If you made a little effort in trying to solve it...we could help you; making homeworks for you is not exactly correct.

Title: Re: How do I calculate the amount of ethanol in a bottle of 12.5% strength wine?
Post by: Chemistry4me on 20/04/2009 01:03:49

I don't understand what you are trying to calculate. Anyway, have a go at it first!

Title: Re: How do I calculate the amount of ethanol in a bottle of 12.5% strength wine?
Post by: Yomi on 20/04/2009 09:34:35

Hey what is this all about %% [???]

Title: Re: How do I calculate the amount of ethanol in a bottle of 12.5% strength wine?
Post by: lightarrow on 20/04/2009 09:45:03

Quote from: Chemistry4me on 20/04/2009 01:03:49

I don't understand what you are trying to calculate. Anyway, have a go at it first!

I think he simply want to compute the molar concentration of ethanol in water, knowing the weight concentration.

Title: Re: How do I calculate the amount of ethanol in a bottle of 12.5% strength wine?
Post by: Bored chemist on 20/04/2009 22:22:39

I think he's after the concentration in moles/litre
Now, in scientific journals I'm quite happy to see that written as M.L-1
but on a website it's likely to get messed up, particularly if the superscripting doesn't work.

Incidentally, it's not as trivial a question as it looks.
You need to be able to convert %v/v to %m/v then convert %m/v to g/l then turn that into moles/litre.
Not rocket science; none of the steps is difficult, but it's easy enough to miss out a stage.
Also someone has thrown a red herring into the data.

Title: Re: How do I calculate the amount of ethanol in a bottle of 12.5% strength wine?
Post by: lightarrow on 21/04/2009 09:23:12

Quote from: Bored chemist on 20/04/2009 22:22:39

I think he's after the concentration in moles/litre
Now, in scientific journals I'm quite happy to see that written as M.L-1
but on a website it's likely to get messed up, particularly if the superscripting doesn't work.

Incidentally, it's not as trivial a question as it looks.
You need to be able to convert %v/v to %m/v then convert %m/v to g/l then turn that into moles/litre.
Not rocket science; none of the steps is difficult, but it's easy enough to miss out a stage.
Also someone has thrown a red herring into the data.

If the data are in v/v then he should know the densities of the mixes water-ethanol.