An ideal gas undergoes isothermal expansion at constant pressure. During the process :

50 mL of 0.2 M ammonia solution is treated with 25 mL of 0.2 M HCl. If pK_b of ammonia solution is 4.75, the pH of the mixture will be :

The electron in the hydrogen atom undergoes transition from higher orbitals to orbital of radius 211.6 pm. This transition is associated with :

At 300 K, the density of a certain gaseous molecule at 2 bar is double to that of dinitrogen (N₂ ) at 4 bar. The molar mass of gaseous molecule is :