One mole each of A and B and 3 moles each of C and D are placed in 11L flask, if equilibrium constant is 2.25 for `A+B hArr C+D` equilibrium concentration of A and C will be in the ratio `:`

Options

A. `2:3`
B. `3:2`
C. `1:2`
D. `2:1`

Answer

A

Explanation

`{:(,A,+,B,hArr,C,+,D),("Initial conc. ",1,,1,,3,,3),("At eqm. ",1-x,,1-x,,3+x,,3+x):}`
`K=([C][D])/([A][B])=((3+x)^(2))/((1-x)^(2))`
`2.25=((3+x)^(2))/((1-x^(2)))`
`:. (3+x)/(1-x)=1.5`
`3+x=1.5-1.5x`
`2.5x=1.5`
`x=(-15)/(25)=(-3)/(5)`
`[A]=1-x=1+(3)/(5)=(8)/(5)` ltbgt `[C]=3+x=3-(3)/(5)=(12)/(5)`
`[A]:[C]=8:12`
or `[A]:[C]=2:3`