1 ml of gaseous aliphatic compound C_nH_3nO_m is completely burnt in an excess of O₂ and cooled to room temperature. The contraction in volume is 

A.   A   (1+1/2n-3/4m)

B.   B   (1+1/4n-1/4m)

C.   C   (1+3/4n-1/4m)

 D.  D   (1+3/4n-1/2m)

     please mention the steps used in finding the answer

P

The gaseous aliphatic organic compound = C_nH_3nO_m 

Volume= 1 mL

The balanced reaction for the combustion is,

CxHyOz + (x+y/4-z/2)O₂ → xCO₂ + y/2H₂O

Here, x=n, y=3n, z=m

Hence, the balanced reaction for the combustion of given organic compound will be,

C_nH_3nO_m + (n+3n/4-m/2₎O₂ → nCO₂ + 3n/2 H₂O

At RT, the volume of H₂O is ognored as it becomes liquid,

Hence, contraction in volume = 1 + n + 3n/4 - m/2 - n = 1+ 3n/4 - m/2

Therefore, the correct answer option is D.