Question

vitamin c is essential for the prevention of scurvy. combustion of 0.2000g of vitamin c gives 0.2998g of CO2 &0.819g of H2O . what is the empirical formula of vitamin c?

Answer 1

let vitamin C empirical formula is CxHy

CxHy + (x +y/4) O2 ------> xCO2 + y/2 H2O

now,
you see 1 mole of vitamin C form x mole CO2 and y/2 mole of H2O

so,
( 0.2000)/(12x+y)= x (0.2998)/(44)

again ,
(0.2000)/(12x + y)= y/2 (0.819)/(18)

divide both ,
1 = x (0.2998). (18)/y/2 (0.819)(44)

y (0.819)(22) = x (0.2998)(18)

x/y = (0.2998)(18)/(0.819)(22)
=3/10

hence ,
empirical formula of vitamin C is C3H10