What is the correct value  of the gas  constant  'R'   from the following ?

^{What happens to the surface tension of water when the temperature is increased ?}

A mixture of NH₃(g) and N₂H₄(g) is placed in a sealed container at 300K. The total pressure is 0.5 atm. When the container is heated to 1200 K, both substances decompose completely according to the equations :

           2NH₃ (g) → N₂(g) + 3H₂(g)

and      N₂H₄(g) →  N₂(g) + 2H₂(g)

After decomposition, the total pressure at 1200 K is found to be 4.5 atm. What is the percent of N₂H₄(g) in the original mixture? (assuming ideal behaviour)

Through the two ends of a glass tube of length 200 cm HCl gas and NH₃ are allowed to enter. At what distance the white ring of ammonium chloride will first appear?

The molar volume of KCL and NaCl are 37.46 mL and 27.94 mL respectively. What is the ratio of the unit cube edges of the crystals ?

In a spinel structure, oxide ions are cubical closed packed whereas 1/8th of tetrahedral voids are occupied by A ions and 1/2 of octahedral voids are occupied by B ions. The charge present on A and B ions will be

What is the coordination number of carbon in diamond ?

Under what  condition will a pure  sample of an  ideal gas not only  exhibit  a pressure  of 1 atm but  also  a concentration of  1mol  L^-1? (R= 0.082  L  atm  mol^-1 deg^-1).

A closed flask contains water in all its three states solid, liquid and vapour at 0^oC. In this situation,what will be the average kinetic energy of water molecules ?

Equal masses of methane and oxygen are mixed in a empty container at 25ºC. The n fraction of the total pressure exerted by oxygen is