On treatment of the following compound with a strong acid, the most susceptible site for bond cleavage is :

$$\Delta $$_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 increasing order of the acidity of the following carboxylic acids is :

The correct order of spin-only magnetic moments among the following is :
(Atomic number : Mn = 25, Co = 27, Ni = 28, Zn = 30)