is a repeating unit for :

Which one of the following species responds to an external magnetic field?

Consider the above reaction, the major product 'P' is :

Sodium stearate CH₃(CH₂)₁₆COO⁻Na⁺ is an anionic surfactant which forms micelles in oil.

Choose the correct statement for it from the following :

The water soluble protein is :

At 298.2 K the relationship between enthalpy of bond dissociation (in kJ mol⁻¹) for hydrogen (E_H) and its isotope, deuterium (E_D), is best described by :

Consider the given reaction, the product 'X' is :

The given reaction can occur in the presence of :

(a) Bromine water

(b) Br₂ in CS₂, 273 K

(c) Br₂/FeBr₃

(d) Br₂ in CHCl₃, 273 K

Choose the correct answer from the options gien below :

Given below are two statements, one is labelled as Assertion (A) and other is labelled as Reason (R).

Assertion (A) : Gabriel phthalimide synthesis cannot be used to prepare aromatic primary amines.

Reason (R) : Aryl halides do not undergo nucleophilic substitution reaction.

In the light of the above statements, choose the correct answer from the options given below :

For the following graphs,

Choose from the options given below, the correct one regarding order of reaction is :

Which one of the products of the following reactions does not react with Hinsberg reagent to form sulphonamide?

The ionic radii of K⁺, Na⁺, Al³⁺ and Mg²⁺ are in the order:

Which one of the following compounds of Group-14 elements is not known?

Which one among the following resonating structures is not correct?

Given below are two statements :

Statement I : None of the alkaline earth metal hydroxides dissolve 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 :

The correct order of following 3d metal oxides, according to their oxidation numbers is :

(a) CrO₃, (b) Fe₂O₃, (c) MnO₂, (d) V₂O₅, (e) Cu₂O

Which one of the following chemical agent is not being used for dry-cleaning of clothes?

Which one of the following compounds will liberate CO₂, when treated with NaHCO₃ ?

In the leaching of alumina from bauxite, the ore expected to leach out in the process by reacting with NaOH is :

An organic compound 'A' C₄H₈ on treatment with KMnO₄/H⁺ yields compound 'B' C₃H₆O.

Compound 'A' also yields compound 'B' an ozonolysis. Compound 'A' is :

The number of sigma bonds in

is _______________.

Three moles of AgCl get precipitated when one mole of an octahedral co-ordination compound with empirical formula CrCl₃.3NH₃.3H₂O reacts with excess of silver nitrate. The number of chloride ions satisfying the secondary valency of the metal ion is ______________.

A source of monochromatic radiation of wavelength 400 nm provides 1000 J of energy in 10 seconds. When this radiation falls on the surface of sodium, x × 10²⁰ electrons are ejected per second. Assume that wavelength 400 nm is sufficient for ejection of electron from the surface of sodium metal. The value of x is ______________. (Nearest integer)

(h = 6.626 × 10⁻³⁴ Js)

CO₂ gas is bubbled through water during a soft drink manufacturing process at 298 K. If CO₂ exerts a partial pressure of 0.835 bar then x m mol of CO₂ would dissolve in 0.9 L of water. The value of x is ____________. (Nearest integer)

(Henry's law constant for CO₂ at 298 K is 1.67 × 10³ bar)

For the reaction

A + B ⇌ 2C

the value of equilibrium constant is 100 at 298 K. If the initial concentration of all the three species is 1 M each, then the equilibrium concentration of C is x × 10⁻¹ M. The value of x is ____________. (Nearest integer)

A spherical gas balloon of radius 16 meter subtends an angle 60^∘ at the eye of the observer A while the angle of elevation of its center from the eye of A is 75^∘. Then the height (in meter) of the top most point of the balloon from the level of the observer's eye is :

Let S_n be the sum of the first n terms of an arithmetic progression. If S_3n = 3S_2n, then the value of S4n/S2n is :

The locus of the centroid of the triangle formed by any point P on the hyperbola 16x² − 9y² + 32x + 36y − 164 = 0, and its foci is :

Let the vectors

Let f : R → R be defined as

where [x] is the greatest integer lss than or equal to x. If f is continuous at x = 2, then λ + μ is equal to :

The value of the definite integral 

The Boolean expression (p ⇒ q) ∧ (q ⇒∼ p) is equivalent to :

The area (in sq. units) of the region, given by the set {(x,y) ∈ R × R|x ≥ 0,2x² ≤ y ≤ 4 − 2x} is :

The sum of all values of x in [0, 2π], for which sin x + sin 2x + sin 3x + sin 4x = 0, is equal to :

Let g : N → N be defined as

g(3n + 1) = 3n + 2,

g(3n + 2) = 3n + 3,

g(3n + 3) = 3n + 1, for all n ≥ 0.

Then which of the following statements is true?

where [x] is the greatest integer less than or equal to x. Which of the following is true?

The values of a and b, for which the system of equations

2x + 3y + 6z = 8

x + 2y + az = 5

3x + 5y + 9z = b

has no solution, are :

Let 9 distinct balls be distributed among 4 boxes, B₁, B₂, B₃ and B₄. If the probability than B₃ contains exactly 3 balls is k(3/4)⁹ then k lies in the set :

Let a parabola b be such that its vertex and focus lie on the positive x-axis at a distance 2 and 4 units from the origin, respectively. If tangents are drawn from O(0, 0) to the parabola P which meet P at S and R, then the area (in sq. units) of ΔSOR is equal to :

The number of real roots of the equation e^6x − e^4x − 2e^3x − 12e^2x + e^x + 1 = 0 is :

Let an ellipse , passes through  and has eccentricity 1/√3. If a circle, centered at focus F(α, 0), α > 0, of E and radius 2/√3, intersects E at two points P and Q, then PQ² is equal to :

Let the foot of perpendicular from a point P(1, 2, −1) to the straight line L : x/1 = y/0 = z/−1 be N. Let a line be drawn from P parallel to the plane x + y + 2z = 0 which meets L at point Q. If α is the acute angle between the lines PN and PQ, then cosα is equal to ________________.

If the value of

is l, then l² is equal to _______________.

Consider the following frequency distribution :
 

If the sum of all frequencies is 584 and median is 45, then | α − β | is equal to _______________.

The ratio of the coefficient of the middle term in the expansion of (1 + x)²⁰ and the sum of the coefficients of two middle terms in expansion of (1 + x)¹⁹ is _____________.