please answer this

Asked by Prashant DIGHE | 6th Jan, 2020, 09:56: PM

Expert Answer:

Option (1) is correct.
 
Given:
 
Density = 1.07 g/ml
 
Molarity = 2.03 M
 
Molar mass of acetic acid = 60.
 
We know,
 
Molarity 
 
Density equals Mass over volume

Mass equals space 1.07 space cross times space 1000

space space space space space space space space space equals 1070 space gm
 
 
Mass of solution = 1.07 kg  
 
No. of moles = 2.03 mole
 
As molarity is no. of moles of solute in 1000 ml of solution.
 
 
No. of moles equals fraction numerator Mass space of space solute over denominator Molar space mass end fraction
 
Mass of solute = No. of moles × Molar mass
 
                      = 2.03 × 60 
 
 
Mass of solute (CH3COOH) = 121.8 gm
 
Mass of solvent = 1070 − 121.8 = 948.2 gm
 
                       = 0.9482 kg
 
Molality  equals fraction numerator 2.03 over denominator 0.9482 end fraction
 
             = 2.15 m
 
Molality  ≈ 2.2 m

Answered by Varsha | 7th Jan, 2020, 01:12: PM

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