Ncert Solutions Chemistry Class 11th

At 298 K, the enthalpy of fusion of a solid (X) is 2.8kJ mol?¹ and the enthalpy of vaporization of the liquid (X) is 98.2 kJ mol?¹. The enthalpy of sublimation of the substance (X) in kJ mol?¹ is ______ (in nearest integer).

The number of sigma bonds in 

Given below are two statements:
Statement I: None of the alkaline earth metal hydroxides dissolves in alkali.
Statement II: Solubility of alkaline earth metal hydroxides in water increases down the group.
In the light of the above statements, choose the most appropriate answer from the options given below:

For water at 100°C and 1 bar, ΔᵥₐₚH - ΔᵥₐₚU = _______ * 10² J mol⁻¹ (Round off to the Nearest integer) [Use: R = 8.31 J mol⁻¹ K⁻¹] [Assume volume of H₂O(l) is much smaller than volume of H₂O(g). Assume H₂O(g) can be treated as an ideal gas]

The density of NaOH solution is 1.2 gm cm⁻³. The molality of this solution is _______ m. (Round off to the Nearest integer) [Use: Atomic masses: Na 23.0u O: 16.0 u H:1.0 u Density of H₂O: 1.0g cm⁻³]

PCl₅ ⇌ PCl₃ + Cl₂ Kc = 1.844. 3.0 moles of PCl₅ is introduced in a 1L closed reaction vessel at 380K. The number of moles of PCl₅ at equilibrium is _______ * 10⁻³. (Round off to the Nearest integer)

The correct order of following 3d metal oxides, according to their oxidation numbers is:
(a) CrO?
(b) Fe?O?
(c) MnO?
(d) V?O?
(e) Cu?O

Which one among the following resonating structure is not correct?
[Images of four resonance structures of an N-oxide compound]

A system does 200 J of work and at the same time absorbs 150 J of heat. The magnitude of the change in internal energy is __________ J. (Nearest integer)

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Lithium halides are some what covalent is nature.
Reason R: Lithium possess high polarisation capability.
In the light of the above statements, choose the most appropriate answer from the options given below: