Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Ionisation enthalpies of early actinoids are lower than for early lanthanoids.
Reason (R) : Electrons are entering 5f orbitals in actinoids which experience greater shielding from nuclear charge.
In the light of the above statements, choose the correct answer from the options given below :
Consider the following reaction :-
$$2 \mathrm{H}_2(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g}) \rightarrow 2 \mathrm{H}_2 \mathrm{O}(\mathrm{g}) \Delta_{\mathrm{r}} \mathrm{H}^{\circ}=-483.64 \mathrm{~kJ} \text {. }$$
What is the enthalpy change for decomposition of one mole of water? (Choose the right option).
Which amongst the following aqueous solution of electrolytes will have minimum elevation in boiling point? Choose the correct option :-
Identify 'X' in the following reaction.