Question #170116

A student determines the molar mass of acetone, CH3COCH3, by the method used in this experiment. He found that the equilibrium temperature of a mixture of ice and water was 1.2oC on his thermometer. When he added 12.2 g of her sample to the mixture, the temperature, after thorough stirring, fell to –3.0oC. He then poured off the solution through a screen into a beaker. The mass of the solution was 100.5 g. How much water was in his decanted solution? 


1
Expert's answer
2021-03-10T06:18:12-0500

mass of acetone added= 12.2 g

mass of solution =100.5 g, moles of acetone=12.258=0.2103\frac{12.2}{58}=0.2103

change inn temp= 4.2

we know that as per depression of freezing point = 1.86

we know that

ΔTf=Kfm\Delta T_f= K_fm

4.2= 1.86×molality\times molality

moles×1000massofwater=4,21.86\frac{moles\times 1000}{mass of water}= \frac{4,2}{1.86}

mass of water=0.2103×1.86×10004.2\frac{0.2103\times 1.86\times 1000}{4.2} = 93.15

so mass of water was= 93.15 g


Need a fast expert's response?

Submit order

and get a quick answer at the best price

for any assignment or question with DETAILED EXPLANATIONS!

Comments

No comments. Be the first!
LATEST TUTORIALS
APPROVED BY CLIENTS