Science (English Medium) Class 11 - CBSE Question Bank Solutions for Chemistry

Assertion (A): Increasing order of acidity of hydrogen halides is \[\ce{HF < HCl < HBr < HI}\]

Reason (R): While comparing acids formed by the elements belonging to the same group of periodic table, \[\ce{H - A}\] bond strength is a more important factor in determining acidity of an acid than the polar nature of the bond.

Which of the following compounds contain all the carbon atoms in the same hybridisation state?

(i) H – C ≡ C – C ≡ C – H

(ii) CH₃ – C ≡ C – CH₃

(iii) CH₂ = C = CH₂

(iv) CH2 = CH – CH = CH₂

For testing halogens in an organic compound with AgNO₃ solution, sodium extract (Lassaigne’s test) is acidified with dilute HNO₃. What will happen if a student acidifies the extract with dilute H₂SO₄ in place of dilute HNO₃?

How much energy is required to ionise an H atom if the electron occupies n = 5 orbit? Compare your answer with the ionization enthalpy of H atom (energy required to remove the electron from n =1 orbit).

Why does benzene undergo electrophilic substitution reactions easily and nucleophilic substitutions with difficulty?

Why is nitric acid added to sodium extract before adding silver nitrate for testing halogens?

Explain the reason for the fusion of an organic compound with metallic sodium for testing nitrogen, sulphur and halogens.

Will CCl₄ give white precipitate of AgCl on heating it with silver nitrate? Give reason for your answer.

Why is it necessary to use acetic acid and not sulphuric acid for acidification of sodium extract for testing sulphur by lead acetate test?

In Lassaigne’s test for nitrogen in an organic compound, the Prussian blue colour is obtained due to the formation of ______.

The ionization constant of HF, HCOOH and HCN at 298K are 6.8 × 10^–4, 1.8 × 10^–4 and 4.8 × 10^–9 respectively. Calculate the ionization constants of the corresponding conjugate base.

The ionization constant of phenol is 1.0 × 10^–10. What is the concentration of phenolate ion in 0.05 M solution of phenol? What will be its degree of ionization if the solution is also 0.01M in sodium phenolate?

The ionization constant of acetic acid is 1.74 × 10^–5. Calculate the degree of dissociation of acetic acid in its 0.05 M solution. Calculate the concentration of acetate ion in the solution and its pH.

The ionization constant of chloroacetic acid is 1.35 × 10–3. What will be the pH of 0.1M acid and its 0.1M sodium salt solution?

Which of the following statement is not correct about the characteristics of cathode rays?

Which of the following order of energies of molecular orbitals of \[\ce{N2}\] is correct?

Which of the following statement is not correct from the view point of molecular orbital theory?

The energy of σ2p_z molecular orbital is greater than π2p_x and π2p_y molecular orbitals in nitrogen molecule. Write the complete sequence of energy levels in the increasing order of energy in the molecule. Compare the relative stability and the magnetic behaviour of the following species :

\[\ce{N2, N^{+}2, N^{-}2, N^{2+}2}\]

Which of the following molecular orbitals has maximum number of nodal planes?

In which of the following molecules, `σ2p_z` molecular orbital is filled after `π2p_x` and `π2p_y` molecular orbitals?