Home
Class 12
CHEMISTRY
The freezing point of a solution contani...

The freezing point of a solution contaning `0.3 g` of acetic acid in `43 g` of benzene reduces by `0.3^(@)`. Calculate the Van's Hoff factor
"(`K_(f)` for benzene =`5.12 K kg mol^(-1)`)"

Text Solution

Verified by Experts

The given values are
`W_(B)=0.3 g`, `DeltaT_(f)=0.30`
`W_(A)=43 g`, `DeltaK_(f)=5.12 K kg mol^(-1)`
Now, using formula
`Mw_(B)=(K_(f)xxW_(B)xx1000)/(DeltaT_(f)xxW_(A))`
`:.Mw_(B)=(5.12xx0.3xx1000)/(0.3xx43)=120 g mol^(-1)`
Normal molar mass =60
`:.i="Normal molar mass"/"Observed molar mass"=60/120=0.5`
Promotional Banner

Similar Questions

Explore conceptually related problems

The freezing point of solution containing 0.2 g of acetic acid in 20.0 g of benzene is lowered by 0.45^(@)C . Calculate the degree of association of acetic acid in benzene. (K_(f)=5.12 K^(@) mol^(-1) kg^(-1))

The freezing point of a solution containing 4.8 g of a compound in 60 g of benzene is 4.48. What is the molar mass of the compound ? ( K_(f)=5.1 Km^(-1) , freezing point of benzene =5.5^(@)C )

Acetic acid associates in benzene to form a dimer. 1.65 g of acetic acid when dissolved in 100 g of benzene raised the boiling point by 0.36^(@)C . Calculate the Van't Hoff factor and degree of association of acetic acid. ( K_(b) for benzene= 2.57^(@)C )

Phenol associates in benzene to a certain extent to form a dimer. A solution containing 20 g of phenol in 1.0 kg of benzene has its freezing point lowered by 0.69 K. Calculate the fraction of phenol that has dimerised. [Given : K_(f) for benzene = 5.1 Km^(-1)]

Phenol associates in benzene to certain extent to form a dimer. A solution containing 20 xx 10^(-3) kg of phenol in 1.0 kg of benzene hs its freezing point depressed by 0.69 K . Calculate the fraction of phenol that has dimerized. ( K_(f) for benzene is 5.12 K kg mol^(-1) ).

An aqueous solution containing an ionic salt having molality equal to 0.19 freezes at -0.704^(@)C . The Van't Hoff factor of the ionic salt is ( K_(f) for water= 1.86 K m^(-1) )

On dissolving 3.24 g of sulphur in 40 g of benzene,the boiling point of the solution was higher than that of benzene by 0.81K .What is the molecular formula of sulphur? ( K_(b) for benzene = 2.53 K kg mol^(-1) , atomic mass of sulphur = 32 g mol^(-1) ).

0.6 mL of acetic acid (CH_(3)COOH) having density 1.06 g mL^(-1) is dissolved in 1 L of water. The depression in freezing point observed for this strength of acid was 0.0205^(@)C .Calculate the Van't Hoff factor and dissociation constant of the acid. K_(f) for H_(2)O=1.86 K kg ^(-1) "mol"^(-1))