Destroyer- CHEM #101

[keliao]

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#101. If 25.20 g of non-volatile, non-dissociating solute was dissolved in 600ml of H2O, the resulting solution boiled at 100.4C. i fthe Kb= 0.51C/m, what is the approximate molecular mass of the solute?
ans.
deltaT = Kb * m* i
.4 = .51m
.8 = m

.8= moles of solute/ kg solvent

.8 = moles/.600 ==> .5moles
MW= g/moles = 25.20/.5 = 50.4g/mole
I dont' understand how 600ml were kg solvent
does ml=kg?????? am lost........can some1help.??

 

[utdent20]

now that you've posted that.. I 've been looking on it too doesn't make sense.. MOLALITY is the m and that is moles/kg and i know ml is not equal to kg in any way.. ml-->l is .600 is what they have.. but i wish someone responds to this.

 

[Albuterol]

density of H2O 1g/mL so u can find the grams of H2O and then the kg

 

[heatwheat]

H2O 1g = 1 mL

Convert mL to g, then g to kg.

 

[keliao]

i would have never thought of that.