a solution containing 6 g of benzoic acid in 50 g of ether (C2H,OC,Hs) has a vapour pressure of 410 mm o mercury at 293 K. Given that the vapour pressure of ether at the same temperature is 442 of calculate the molecular mass of benzoic acid. (Assume that the solution is dilute)

Asked by Jatinaa786 | 4th Apr, 2019, 05:18: PM

Expert Answer:

F o r space V e r y space d i l l u t e space s o l u t i o n comma space w e space h a v e space f r o m space r a o u l t apostrophe s space l a w minus

fraction numerator P subscript 0 minus P subscript s space space over denominator P subscript o end fraction space equals space fraction numerator M o l e s subscript S o l u t e end subscript over denominator M o l e s subscript S o l v e n t end subscript end fraction

fraction numerator 442 minus 410 over denominator 442 end fraction space equals space fraction numerator 6 divided by M over denominator 50 divided by 74 end fraction space left parenthesis space 74 space equals space m a s s space o f space e t h e r comma space C subscript 2 H subscript 5 O C subscript 2 H subscript 5 right parenthesis

W e space f i n d space M space equals space 122.6 g space left parenthesis M o l e c u l a r space m a s s space o f space b e n z o i c space a c i d right parenthesis

Answered by Ravi | 5th Apr, 2019, 01:31: AM