The mole fraction of a solvent in aqueous solution of a solute is 0.8. The molality (in mol kg^–1 ) of the aqueous solution is :

The electrons are more likely to be found :

An organic compound 'A' is oxidizod with Na₂O₂ followed by boiling with HNO₃. The resultant solution is then treated with ammonium molybdate to yield a yellow precipitate.
Based on above observation, the element present in the given compound is:

Enthalpy of sublimation of iodine is 24 cal g^–1 at 200 ^oC. If specific heat of I₂(s) and l₂ (vap) are 0.055 and 0.031 cal g^–1K ^–1 respectively, then enthalpy of sublimation of iodine at 250 ^oC in cal g^–1 is :