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Confusion with moles/mass calculation watch

1. Right, so here is the question:

Given the density of ethanol is 0.789 g cm3 we can convert the concentration to %ABV.
(a) Using the RMM of ethanol work out what mass of ethanol is present in 1 dm3 of the unknown sample.
(b) What mass would be present in 100 cm3, this is the % by mass.
(c) Use the density of ethanol to convert the % by mass into a %ABV.
(d) Finally state which bracket the cider sample should be taxed in.

Background info:

Concentration of the unknown is 0.04moldm-3 and the volume is 4ml. it was a practical and we were given that information.

How would you work out the %ABV?

Thanks so much!!!!

Lots of plus rep available

Thanks
3. Hi, You must be in Group 1 with me. Have you managed to figure it out yet? If not..I'll try and help.
4. (Original post by chemicalX)
Right, so here is the question:

Given the density of ethanol is 0.789 g cm3 we can convert the concentration to %ABV.
(a) Using the RMM of ethanol work out what mass of ethanol is present in 1 dm3 of the unknown sample.
(b) What mass would be present in 100 cm3, this is the % by mass.
(c) Use the density of ethanol to convert the % by mass into a %ABV.
(d) Finally state which bracket the cider sample should be taxed in.

Background info:

Concentration of the unknown is 0.04moldm-3 and the volume is 4ml. it was a practical and we were given that information.

How would you work out the %ABV?

Hello! I've tried calculate a value but now I'm stuck.

The concentration for the unknown sample was 0.05. I used that to work the %mass (which turned out to be 0.23g in 100cm3). I then divided it by the density and got 0.29.

I don't know what to do next. Do I multiple it by 100 to get a % or is that the %ABV?

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