Question

Determine the osmotic pressure (in atm) , at 80.2 o F, of an aqueous Iron (II) nitrate solution whose mole fraction of solute is 0.002696.

Density solution = 1.11 g/mL

Answer 1

PV= nRT
So Posm = nRT/V

R= 0.08206 L*atm/mol*k

T= 80.2F = 299.928 K

V = calculate somehow using density

n = reverse mole fraction calculation to find total moles of solution

Answer 2

@taramgrant0543664 @photon336 Can you guys assist me in reversing the mole fraction equation to find total moles of solution and then using that calculation with the density to find volume?

Answer 3

V=m/d
where v is volume, m is mass and d is density

Answer 4

right, but i can't find the mass of the solution until i reverse the mole fraction and find moles of total solution

Answer 5

I think? Mole fraction = (moles solute) / (moles solute + moles solv ). We are given moles of solute, but I don't know where to go from here. :(

Answer 6

Yes that is the formula

Answer 7

You're not given moles of solvent?

Answer 8

@Abhisar @pooja195 @zepdrix @abb0t

Answer 9

Nope. :/

Answer 10

Hmmm... I don't know to tell you sorry I've only touched on osmotic pressure stuff none of my profs or teachers really talked much about it so I don't want to lead you on the wrong direction

Answer 11

Do you know anyone online that can help me? @taramgrant0543664

Answer 12

I think you got a majority of the ones that could hopefully help

Answer 13

@abb0t Do you think you can help me?

Answer 14

@NoelGreco Hi! Can you please help me?

Answer 15

@Lena772 can you find out molality ?

Answer 16

yes moles solute/kg solvent. But I don't know the moles of solute.

Answer 17

Here is a formula :-
\[\large \bf Molality=\frac{X_{solute}\times 1000 }{(1-X_{solute}) \times M_{solvent}}\]

Answer 18

and then use this :-
\[\large \bf Molarity=\frac{molality \times density \times 1000}{molality \times Molar~ mass~ of~ solute+1000}\]

Answer 19

hope you can find molarity

Answer 20

Molal = (0.002696 mol Solute * 1000) / ( 0.997304 * molality of solvent) , BUT idk the molality of the solvent

Answer 21

its molar mass of solvent

Answer 22

not molality of the solvent
Remember molality is denoted by small m i.e `m`

Answer 23

Molal = (0.002696 mol Solute * 1000) / ( 0.997304 * 175.8948)

Answer 24

after you find out molarity !
Use this :-
\[\large \bf Osmotic~Pressure(\pi)=Molarity \times RT \times vant~hoff~factor\]

Answer 25

0.015368778 molal ?

Answer 26

i don't know.
Use calculator

Answer 27

i am here to give you HINTS as possible

Answer 28

molality = 0.94396197

0.94396197 * 0.08206 * 299.928 K * van hoult?

Answer 29

you don't know vant hoff factor ?

Answer 30

denoted by `i`

Answer 31

@Lena772 then first learn this term and then solve the rest of question

Answer 32

any problem ???

Answer 33

Would the factor be 4 because there is 3 pieces of iron nitrate and 1 piece of water molecule?

Answer 34

@mayankdevnani

Answer 35

nope !
try again

Answer 36

What's wrong about it?

Answer 37

see the oxidation state of iron in question.

You took the oxidation state as +3

Answer 38

So van hoff is 3 ?

Answer 39

yup

Answer 40

I get 69.7 atm. That's sounds extreme. Can you just plug those in and see if you get the same value?

Answer 41

lol
but i don't have much time to solve !
Sorry !
Better luck ,Next time

Answer 42

i have to go now !
Bye ! @Lena772
Its been a nice time with you ! :)

Answer 43

MEDAL for your HARDWORK and keen interest on solving this question !

Answer 44

REMEMBER :- Don't suppose that i am a professor, i am (18)-