Mole concept - PLS help
Q- (100gm of CuSO4 . 5 H2O is dissolved in 500 g of water to form aq solution. find molarity & molality of Cu2+ if density of solution is 1.2 g/ml [Cu=64] [S=96])
isme sir ne bola water of crystallisation ka bhi mass lena hoga molality find krne ke liye or usme unhone water of crystallisation ke 2.5 mole liye , ye smajh nhi aaya
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@Dexter
Note for OP
+solved @user1 @user2... to close the thread when your doubt is solved. Mention the users who helped you solve the doubt. This will be added to their stats.using the mole of h20 in water of crystallisation and the moles in the the voulme of water throught tht cal the molality of it
160 g/mol is the molar mass of copper sulphate, with 5 mol water it would be +90 g. does that help?
out of the 100 g, 100/250 * 90 is the mass of water ie 36 g
molality is just moles of Cu2+ / mass, i.e. 0.4/0.536
do you have the pic of the question?
ohh ok since here moles of cuso4. 5h20 is .5 thts why h20 is 2.5 moles
i was doing the same but then the teacher tok 0.5 mole for the calculation and did 0.5 x 5x18 for the total mass and i got confused as the no. of moles were 0.4 as we calculated it beforehand , it made me very confused that how it went from 0.4 to 0.5 out of nowhere , and cant seem to find the mistake if its on his part or lack of my understanding
0.4 moles nhi hone chaiye? 100/250 = 0.4 hoga and 0.4 * 90 gives us mass of water
or am i wrong here?
i think the soln here is wrong
wait a sec
since when is S molar mass 96
its 32
im getting molarity as 0.8
and molality as 0.748
yea woh sulphate ka likha hoga
i got 0.746 as molality is that much acceptable ?
+solved @iTeachChem @Sephrina
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