In KO₂, the nature of oxygen species and the oxydation state of oxygen atom are, respectively :

Following four solutions are prepared by mixing different volumes of NaOH and HCl of different concentrations, pH of which one of them will be equal to 1 ?

$$\Delta $$_fG^o at 500 K for substance 'S' in liquid state and gaseous state are +100.7 kcl mol-¹ and +103 kcal mol^-1, respectively. Vapour pressure of liquid 'S' at 500 K is approximately equal to : ( R = 2 cal K^-1 mol^-1 )

The de-Broglie's wavelength of electron present in first Bohr orbit of 'H' atom is :