JEE Advanced 2026 Paper-1

The $$2s$$ and the $$2p$$ orbital energies of hydrogen atom are $$E_{2s}(\mathrm{H})$$ and $$E_{2p}(\mathrm{H})$$, respectively. The $$2s$$ and the $$2p$$ orbital energies of lithium atom are $$E_{2s}(\mathrm{Li})$$ and $$E_{2p}(\mathrm{Li})$$, respectively. The correct option(s) about the orbital energies is(are)

Correct statement(s) about the compounds $$\mathbf{X}$$, $$\mathbf{Y}$$ and $$\mathbf{Z}$$ is(are)

Reaction of $$PtF_6$$ with oxygen $$(O_2)$$ gas results in the formation of an ionic compound, $$\mathbf{X^{+}Y^{-}}$$. Correct statement(s) is(are)

In the following reaction sequence, $$\mathbf{Q}$$, $$\mathbf{R}$$, $$\mathbf{S}$$ and $$\mathbf{T}$$ are the major products.

The correct statement(s) about $$\mathbf{Q}$$, $$\mathbf{R}$$, $$\mathbf{S}$$ and $$\mathbf{T}$$ is(are)

Two cylinders, both fitted with frictionless pistons, are filled with mixtures of $$\mathrm{He}$$ and $$\mathrm{Ar}$$ gases. In the first cylinder, the masses of $$\mathrm{He}$$ and $$\mathrm{Ar}$$ are $$m_1$$ and $$m_2$$, respectively. In the second cylinder, the masses of $$\mathrm{He}$$ and $$\mathrm{Ar}$$ are $$m_2$$ and $$m_1$$, respectively. The molar mass of $$\mathrm{Ar}$$ is $$10$$ times the molar mass of $$\mathrm{He}$$. The external pressure applied by the piston on the first cylinder needs to be $$5$$ times that on the second cylinder so that the volume of the gas mixtures in both the cylinders are equal at the same temperature. Assuming $$\mathrm{He}$$ and $$\mathrm{Ar}$$ behave like ideal gases, the value of $$(m_1/m_2)$$ is ___.

The total number of all possible isomers for the square planar complex with formula $$K[M(NCS)(NO_2)(gly)]$$ is ___.

(M = metal ion and gly = $$NH_2CH_2COO^{-}$$)

The sum of total number of carbonyl groups $$(>C=O)$$ present in the major products $$\mathbf{X}$$ and $$\mathbf{Y}$$ in the following reactions is ___.

Treatment of buta-$$1,3$$-diyne with $$NaNH_2$$ ($$2$$ equivalents), followed by reaction with excess of trans-$$CH_3\text{-}CH\!=\!CH\text{-}CH_2\text{-}Br$$ gives $$\mathbf{X}$$ as the major product. The maximum number of carbon atoms that are collinear (in a straight line) in $$\mathbf{X}$$ is ___.

List-I contains various physical/chemical processes, and List-II contains combinations of changes in enthalpy $$(\Delta H)$$ and entropy $$(\Delta S)$$. Match each entry in List-I to the appropriate entry in List-II, and choose the correct option.

Consider the following species:

$$SOCl_2$$, $$XeOF_4$$, $$ClF_3$$, $$ClF_5$$, $$XeF_5^{+}$$, $$SO_3^{2-}$$, $$XeF_3^{+}$$, $$SF_4$$

List-I contains different molecular shapes and List-II contains total number of species with the same molecular shapes from the given species. Match each entry in List-I with the appropriate entry in List-II and choose the correct option.