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Chemistry 22 Online
OpenStudy (superhelp101):

A solution is made by dissolving 19.5 grams of glucose (C6H12O6) in .245 kilograms of water. If the molal freezing point constant for water (Kf) is -1.86 °C/m, what is the resulting freezing point of the solution? Show all of the work needed to solve this problem.

OpenStudy (superhelp101):

@Nurali

ganeshie8 (ganeshie8):

I think we need to use this equation \[\large \Delta T_f = iK_f m_{solute}\]

OpenStudy (superhelp101):

yes we do

ganeshie8 (ganeshie8):

\(i = 1\) for glucose you're given \(K_f = -1.86^{\circ}C/m \)

ganeshie8 (ganeshie8):

know how to calculate the molality \(\large m_{solute }\) ?

OpenStudy (superhelp101):

molarity = moles of solute/ volume of solution in litres @chmvijay

OpenStudy (chmvijay):

Molalaity = moles /litre of solution Molality= moles /Kg of solution

OpenStudy (superhelp101):

don't i have to convert something to moles?

OpenStudy (chmvijay):

19.5 grams of glucose

OpenStudy (chmvijay):

moles = gram/molar mass :P

OpenStudy (superhelp101):

do i just plug 19.5 in the equation?

OpenStudy (chmvijay):

which equation lol moles of glucose=19.5 / molar mass of glucose

OpenStudy (superhelp101):

ohhh ok 19.5/ 180.1559

OpenStudy (chmvijay):

yaaa its mole now u calculate MOLALITY

OpenStudy (superhelp101):

.10823959

OpenStudy (chmvijay):

lol what is this :P

OpenStudy (superhelp101):

19.5/ 180.1559= .10823959 :)

OpenStudy (chmvijay):

itsa mole of glucose u wanted to find molality right ? molality = moles of glucose /kg of solution

OpenStudy (superhelp101):

wait i am so confused? :(

OpenStudy (chmvijay):

first u have to find moles of glucose then u have to find out the molality of glucose solution :P

OpenStudy (chmvijay):

|dw:1406269257795:dw|

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