A commercially sold conc. HCl is 35% HCl by mass. If the density of this commercial acid is 1.46 g/mL, the molarity of this solution is:

(Atomic mass : Cl = 35.5 amu, H = 1 amu)

An evacuated glass vessel weighs 40.0 g when empty, 135.0 g when filled with a liquid of density 0.95 g mL^$$-$$1 and 40.5 g when filled with an ideal gas at 0.82 atm at 250 K. The molar mass of the gas in g mol^$$-$$1 is :

(Given : R = 0.082 L atm K^$$-$$1 mol^$$-$$1)

If the radius of the 3^rd Bohr's orbit of hydrogen atom is r₃ and the radius of 4^th Bohr's orbit is r₄. Then :

Consider the ions/molecule

O$$_2^ + $$, O₂, O$$_2^ - $$, O$$_2^ {2-} $$

For increasing bond order the correct option is :