Volumetric/Gravimetric Analysis

[xD_aQt]

Hi,
I have a few questions that I don't understand. I was hoping someone could help me.
Any help to get me started would be much appreciated! Thanks :smitten:

[jayfan]

simply work out the questions step by step - they are ordered to guide you through:

a) 10% (w/v) means 10 g per 100 mL. given the mass per 100 mL, you can get the molarity by n = m/M in 100 mL, and then multiply by 10 to get unit into mol/L.

b) multiple previous answer by 10/250

hope this will give you started

[xD_aQt]

a) 10% (w/v) means 10 g per 100 mL. given the mass per 100 mL, you can get the molarity by n = m/M in 100 mL, and then multiply by 10 to get unit into mol/L.
b) multiple previous answer by 10/250

a) so does (w/v) mean g per 100ml ? --> so in this case its 10 g per 100ml? --> and since the answer has to be mol/L would I times the top and bottom by 10?
b) ummm .. haha I don't understand why you put 10/250

[vexx]

^

a) yes w/v is weight-volume concentration where it will be 10g per 100ml, and no just times the whole answer by 10 cos it's in 100ml, turning it into 1.00 L
b) times it by 10/250 because you are converting from the original sample to a 10ml sample to a 250ml sample
concentration of original sample x (10/250) = concentration of diluted sample
(hopefully this is right haha)