Orlon fibres are made up of :

Given below are two statements : One is labelled as Assertion A and other is labelled as Reason R.

Assertion A : The dihedral angles in H₂O₂ in gaseous phase is 90.2$$^\circ$$ and in solid phase is 111.5$$^\circ$$.

Reason R : The change in dihedral angle in solid and gaseous phase is due to the difference in the intermolecular forces.

Choose the most appropriate answer from the options given below for A and R.

Chemical nature of the nitrogen oxide compound obtained from a reaction of concentrated nitric acid and P₄O₁₀ (in 4 : 1 ratio) is :

An inorganic Compound 'X' on treatment with concentrated H₂SO₄ produces brown fumes and gives dark brown ring with FeSO₄ in presence of concentrated H₂SO₄. Also Compound 'X' gives precipitate 'Y', when its solution in dilute HCl is treated with H₂S gas. The precipitate 'Y' on treatment with concentrated HNO₃ followed by excess of NH₄OH further gives deep blue coloured solution, Compound 'X' is :