Question

when 2.5 gram of non volatile solute added into 75 gram of water the vapour pressure of solution is found to be 710 mm of Hg what will be molar mass of solute if vapour pressure of pure solvent is 700 mm of Hg ..... quick ans. plzz ....i am waiting ....​

Answer 1

Answer:

hi

Explanation:

X  

solute

​  

=0.9

P  

H  

2

​  

O

o

​  

=30 mm Hg

ΔP=X  

solute

​  

×P  

H  

2

​  

O

o

​  

 

=0.9×30mm Hg

=27 mm Hg

So, the correct option is C

Answer 2

Answer:

Molar mass of solute = 2.5 / 0.06 = 41.67

Explanation:

The formula that would be applied is;

(Pactual − Pnew)/ Pactual = nsolute / nsolvent

Here Pactual is the original vapor pressure, and P new is the vapor pressure after the solute is added to solvent. Also nsolute is the number of moles of solute and nsolvent is the number of moles of solvent

Now,

number of moles of water = 75 / 18 = 4.167

700 - 710 / 700 = nsolute / 4.167

nsolute = 0.06  

Molar mass of solute = 2.5 / 0.06 = 41.67