Question

Which of the following relations is not correctly matched with the formula ?
A. In case of association, `alpha=(i-1)/(1/n-1)`
B. In case of dissociation, `alpha=(i-1)/(n+1)`
C. Relative lowering of vapour pressure `=(p_A^@ - p_A)/p_A^@ =i(n_B)/(n_A+n_B)`
D. Elevation in boiling point, `DeltaT_b=K_b xx(W_Bxx1000)/(M_BxxW_A)`

Answer 1

Correct Answer - B
In case of dissociation : `A_n to nA`
`{:("Initial number of moles",1,0),("After dissociation",1-alpha,nalpha):}`
No. of particles = `1-alpha+nalpha`
`i=(1-alpha+nalpha)/1` or `i=1-alpha+nalpha`
i-1=`nalpha-alpha=(n-1)alpha therefore alpha=(i-1)/(n-1)`