List of top Questions asked in CBSE CLASS XII

Figure 9.37 shows an equiconvex lens (of refractive index 1.50) in contact with a liquid layer on top of a plane mirror. A small needle with its tip on the principal axis is moved along the axis until its inverted image is found at the position of the needle.

Integrate the function: \(e^{2x} sinx\)

Integrate the function: \(cot \ x .log\ sin\  x\)

Find the integrals of the function: \(cos^4 2x\)

Integrate the function: \(\frac{x+2}{\sqrt {x^2+2x+3}}\)

Find \(\frac {dy}{dx}\): \(2x+3y=sin\ x\)

Find \(\frac {dy}{dx}\): \(xy+y^2=tan\ x+y\)

Find \(\frac {dy}{dx}\): \(x^2+xy+y^2=100\)

Find \(\frac {dy}{dx}\): \(x^3+x^2y+xy^2+y^3=81\)

A solution is obtained by mixing 300 g of \(25\%\) solution and 400 g of \(40\%\) solution by mass. Calculate the mass percentage of the resulting solution.

How many mL of 0.1 M HCL are required to react completely with 1g mixture of \(\text{Na}_2\text{CO}_3\) and \(\text{NaHCO}_3\) containing equimolar amounts of both?

A solution of glucose in water is labelled as \(10\%\) \(\text{w/w}\), what would be the molality and mole fraction of each component in the solution? If the density of solution is \(1.2\, \text{g mL}^{–1}\), then what shall be the molarity of the solution?

Concentrated nitric acid used in laboratory work is \(68\%\) nitric acid by mass in aqueous solution. What should be the molarity of such a sample of the acid if the density of the solution is \(1.504\, \text{g mL}^{–1}?\)

Give an example of a solid solution in which the solute is a gas.

Find \(\frac {dy}{dx}:\) \(y=cos^{-1}(\frac {1-x^2}{1+x^2}),\ \ 0<x<1\)

Find \(\frac {dy}{dx}:\) \(sin^2x+cos^2y=1\)

\(Find\  \frac {dy}{dx}:\) \(y=tan^{-1}( \frac {3x-x^3}{1-3x^2}),\ \ -\frac {1}{\sqrt 3}<x<\frac {1}{\sqrt 3}\)

How much electricity is required in coulomb for the oxidation of 
(i) 1 mol of H₂O to O₂. 
(ii) 1 mol of FeO to Fe₂O₃.

Conductivity of 0.00241 M acetic acid is 7.896 × 10^-5 S cm^-1 . Calculate its molar conductivity and if \(\land^0_m\) for acetic acid is 390.5 S cm² mol^-1 , what is its dissociation constant?

The resistance of a conductivity cell containing 0.001M KCl solution at 298 K is 1500 Ω. What is the cell constant if conductivity of 0.001M KCl solution at 298 K is 0.146 x 10^-3 S cm^-1 .

Define conductivity and molar conductivity for the solution of an electrolyte. Discuss their variation with concentration.

Calculate the standard cell potentials of galvanic cells in which the following reactions take place: 
 (i)  \(2Cr_{(S)}+3Cd^{2+}_{(aq)} \rightarrow 2Cr^{3+}_{(aq)}+3Cd\)
 (ii) \(Fe^{2+}_{(aq)}+Ag^+_{(aq)} \rightarrow Fe^{3+}_{(Aq)}+Ag(s)\)
Calculate the \(\triangle_rG^\ominus\) and equilibrium constant of the reactions.

Given the standard electrode potentials, 
K⁺/K = -2.93V, Ag⁺/Ag = 0.80V, 
Hg²⁺/Hg = 0.79V 
Mg²⁺/Mg = -2.37 V, Cr³⁺/Cr = - 0.74V 
Arrange these metals in their increasing order of reducing power.

Arrange the following metals in the order in which they displace each other from the solution of their salts.
Al, Cu, Fe, Mg and Zn