The 1st, 2nd and 3rd ionisation enthalpies, I₁, I₂ and I₃, of four atoms with atomic numbers n, n + 1, n + 2, and n + 3, where n < 10, are tabulated below. What is the value of n?

Consider the following compounds in the liquid form :

O₂, HF, H₂O, NH₃, H₂O₂, CCl₄, CHCl₃, C₆H₆, C₆H₅Cl

When a charged comb is brought near their flowing stream, how many of them show deflection as per the following figure?

In the chemical reaction between stoichiometric quantities of KMnO₄ and KI in weakly basic solution, what is the number of moles of I₂ released for 4 moles of KMnO₄ consumed?

An acidified solution of potassium chromate was layered with an equal volume of amyl alcohol. When it was shaken after the addition of 1 mL of 3% H₂O₂, a blue alcohol layer was obtained. The blue colour is due to the formation of a chromium (VI) compound 'X'. What is the number of oxygen atoms bonded to chromium through only single bond in a molecule of X?