Identify the correct statement regarding a spontaneous process :

In conversion of lime-stone to lime,
CaCO₃(s) $$\to$$ CaO(s) + CO₂ (g) the vales of ∆H° and ∆S° are +179.1 kJ mol−1 and 160.2 J/K respectively at 298 K and 1 bar. Assuming that ∆H° do not change with temperature, temperature above which conversion of limestone to lime will be spontaneous is :

Which of the following reactions will yield 2, 2-dibromopropane?

The actinoids exhibits more number of oxidation states in general than the lanthanoids. This is because :