Aqueous solution of which salt will not contain ions with the electronic configuration 1s²2s²2p⁶3s²3p⁶ ?

Consider the reaction sequence below :


X is:

The rate law for the reaction below is given by the expression k [A] [B]

A + B $$ \to $$ Product

If the concentration of B is increased from 0.1 to 0.3 mole, keeping the value of A at 0.1 mole, the rate constant will be :

The bond angle H - X - H is the greatest in the compound :