I believe it’s Refractive index
The answer is (A).
Hope this helps :).
When an electron transit from lower level to higher level it emits energy
When an electron transit from higher level from a lower level it absorbs energy
n=3 to n=5, : absorption
n=1 to n=3, : absorption
n=3 to n=2, : emission
n=2 to n=1 : emission
the highest energy means highest wave number
wave number = Rh (1/ n1^2 - 1/n2^2)
Rh = 1.1 X 10^7 m^-1
1) n=3 to n=5
wavenumber = Rh ( 1/ 9 - 1/ 25) = 0.071 Rh
2) n=1 to n=3
wavenumber = Rh ( 1- 1/9 ) = 0.89 Rh
3) n=3 to n=2
wavenumber = Rh ( 1/4 - 1/9) = 0.139 Rh
4) n=2 to n=1
wavenumber = Rh ( 1- 1/4) = 0.75 Rh
Thus for 2) n=1 to n=3 energy will be maximum
Answer: Molecular weight of this compound is 387.3g/mol
Explanation:
As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.
The formula for relative lowering of vapor pressure will be,
where,
= relative lowering in vapor pressure
i = Van'T Hoff factor = 1 (for non electrolytes)
= mole fraction of solute =
Given : 18.16 g of compound is present in 228.6 g of benzene
moles of solute = 
moles of solvent (benzene) = 
= mole fraction of solute =
The molecular weight of this compound is 387.3g/mol
