Question

Mole fraction of C2H5OH in aqueous solution is 0.25. If the density of solution is 0.967g/ml. calculate molarity and molality.

Joshi sir comment

0.75 mole water contains ...................................... 0.25 mole C2H5OH

so 0.75*18 gm contains ....................................... 0.25 mole

now calculate moles of alcohol in 1000 gm water. It will be molality

similarly

0.75 mole water contains ...................................... 0.25 mole C2H5OH

so 0.75*18 gm contains ....................................... 0.25*46 gm

so 0.75*18+0.25*46 gm solution contains ........................... 0.25 mole alcohol

so (0.75*18+0.25*46)*0.967 ml solution contains ............................. 0.25 mole alcohol

now calculate moles of alcohol in 1000 ml solution. It will be molarity

 

 

 

Read 2 Solution.

o.25=n/n+55.5  find n ie moles of c2h5oh and then find molality & molarity

SARIKA 11 year ago is this solution helpfull: 5 1

denstiy se vol find and moles se find mass of c2h5oh and now put in formula 4 molality and molarity

SARIKA 11 year ago is this solution helpfull: 5 2

Submit Your Answer


please login to submit your answer

Login Here

Register