AskGin GUJCET/Board ExamFreezing point of urea solution is -0.6° C.Ho

1.	AskGin GUJCET/Board ExamFreezing point of urea solution is -0.6° C.How much urea is required to be dissolved in3 kg water?[M(urea) = 60 g mol!, K = 1.5°C Kg mol
Answer» Answer: Amount of UREA = 1.02g no. of mole = 1.02/60 MOLAR mass of urea (NH 2 CONH 2 )=60 Molality = 60 1.02 × 98.5 1000 =0.17259 ΔT f =K f m⇒0.211=k f ×0.1759 ...(i) LET molar mass of unknown COMPOUND = M ΔT f =k f m ΔT f =k d × M 1.60 . 80.6 1000 0.34=k f × M 19.85 ...(ii) divide equation (i) by (ii) 0.34 0.211 = 19.85 0.1759 ×M M= 0.34×17.59 0.211×19.85 =70gm

AskGin GUJCET/Board ExamFreezing point of urea solution is -0.6° C.How much urea is required to be dissolved in3 kg water?[M(urea) = 60 g mol!, K = 1.5°C Kg mol

Answer»

Answer:

Amount of UREA = 1.02g

no. of mole = 1.02/60

MOLAR mass of urea (NH

CONH

)=60

Molality =

1.02

98.5

1000

=0.17259

ΔT

m⇒0.211=k

×0.1759 ...(i)

LET molar mass of unknown COMPOUND = M

ΔT

1.60

80.6

1000

0.34=k

19.85

...(ii)

divide equation (i) by (ii)

0.34

0.211

19.85

0.1759

×M

0.34×17.59

0.211×19.85

=70gm