`4.5` moles each of hydrogen and iodine heated in a sealed 10 litrevesel. At equilibrium, 3 moles of HI was foun. The equilibrium constant for `H_(2)(g) + I_(2) (g)hArr2HI(g)` is

Options

A. 1
B. 10
C. 5
D. 0.33

Answer

A

Explanation

`{:(,H_(2),+,I_(2),hArr,2HI),("At start",4.5,,4.5,,-),("At equilibrium",(4.5-x),,(4.5-x),,2x):}`
`2x=3` or `x=(3)/(2) ` or `x=1.5`
Thus at equilibrium, `[H_(2)]=4.5-1.5=3`
`[I_(2)]=4.5-1.5=3`
`[HI]=2x=2xx1.5=3`
`K=([HI]^(2))/([H_(2)][I_(2)])=(3xx3)/(3xx3)=1`