Class 11th

Let the equation of the pair of lines, y = px and y = qx, can be written as (y - px)(y - qx) = 0. Then the equation of the pair of the angle bisectors of the lines x² - 4xy – 5y² = 0 is:

The sum of all those terms which are rational numbers in the expansion of (2¹/³ + 3¹/?)¹² is:

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]

If a tangent to the ellipse x² + 4y² = 4 meets the tangents at the extremities of its major axis at B and C, then the circle with BC as diameter passes through the point:

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]

The difference between bond orders of CO and NO⁺ is x/2 where x is _______. (Round off to the Nearest integer)

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]