Diborane on hydrolysis gives a compound $X$. The correct statement about $X$ are

I. It is a tribasic acid

II. It is a weak monobasic acid

III. It has a layer structure

IV. It is highly soluble in water

Choose the correct statement about allotropes of carbon.

I. Graphite has layered structure.

II. Buckminster fullerene is not aromatic in nature.

III. The distance between two adjacent layers in graphite is 141.5 pm .

IV. The hybridisation of carbon in graphite and Buckminster fullerene is same.

Which one of the orders is correctly matched with the property mentioned against it?

Noble gas ' $X$ ' is used as a diluent for oxygen in modern diving apparatus and noble gas ' $Y$ ' is used mainly to provide an inert atmosphere in high temperature metallurgical processes ' $Y$ ' and ' $X$ ' are respectively?