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Question : 29
Total: 35
When 19.5 g F − C H 2 − C O O H = 78 g m o l − 1 500 g 1 ° C
Calculate the degree of dissociation of F − C H 2 −
[Given :K f = 1.86 K k g m o l − 1
Calculate the degree of dissociation of
[Given :
Solution: 👈: Video Solution
Molecular mass of 78 g ∕ m o l
( F − C H 2 C O O H )
No. of moles of fluoroacetic acid is
= 0.25
Molality is the number of moles of solute in1 k g
Molality=
= 0.50 m
Δ T f = K f × m = 1.86 × 0.50 = 0.93 K
i =
= 1.0753
C H 2 F C O O H → C H 3 F C O O − + H +
C ( 1 − α ) C α C α
Total number of moles= C ( 1 − α ) + C α + C α = C ( 1 + α )
i =
= 1 + α = 1.0753
α = 0.0753
(ii)( α = 0.50 × 0.0753 = 0.03765
C ( 1 − α ) = 0.50 ( 1 − 0.0753 ) = 0.462
No. of moles of fluoroacetic acid is
Molality is the number of moles of solute in
Molality
Total number of moles
(ii)
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