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Density Hw

An enmpty pycnometer weighed 25.296g. When filled with water at 25C, it weighed 34.914g. When filled with unknown liquid, it weighed 33.485g. Give the density of water is 0.99705g/mL. Calculate the density of the unknown liquid.

Chloroform has a density of 1.492g/mL and propylene glycol has a density of 1.043g/mL. When 35.00mL of chloroform and 25.70mL of propylene glycol mixed together, what is the density of the mixture?

 Nebula 08-20-2012 03:50 PM

http://i.imgur.com/NPLX0.jpg
http://i.imgur.com/P1Prt.jpg

Making you do the last step to make sure you understand it. Make sure you do a similar problem in your spare time.

For the second problem. You need to work out the mass of each of the components and then add them up. Once you have done this, divide by the total volume to get density.

Multiply the volume by the density to get the mass.

If you need any more help, feel free to post. Same goes if you are confused about what I have done.

for the unknown liquid i got 8.189g, is that right? cuz i got the number of the unknown liquid subtracted with how much the enemy pycnometer.

 Nebula 08-20-2012 04:39 PM

8.189g is correct for the mass of the unknown liquid. When you divide by volume you will get density which should be 0.849g/ml.

Quote:
 Originally Posted by Cepheid (Post 1760394) 8.189g is correct for the mass of the unknown liquid. When you divide by volume you will get density which should be 0.849g/ml.
o thx, i guess i did it right without knowing it, it looked weird to me, so i just had to post it

 Nebula 08-20-2012 07:14 PM

No. How did you go with the second question?