Science (English Medium) कक्षा ११ - CBSE Question Bank Solutions for Chemistry

The pH of 0.1M solution of cyanic acid (HCNO) is 2.34. Calculate the ionization constant of the acid and its degree of ionization in the solution.

Calculate the pH of the resultant mixtures: 10 mL of 0.2M Ca(OH)₂ + 25 mL of 0.1M HCl.

Calculate the pH of the resultant mixtures: 10 mL of 0.01M H₂SO₄ + 10 mL of 0.01M Ca(OH)₂.

Calculate the pH of the resultant mixtures: 10 mL of 0.1M H₂SO₄ + 10 mL of 0.1M KOH

Show the distribution of electrons in oxygen atom (atomic number 8) using orbital diagram.

Acidity of \[\ce{BF3}\] can be explained on the basis of which of the following concepts?

In which of the following solvents is silver chloride most soluble?

The aqueous solution of sugar does not conduct electricity. However, when sodium chloride is added to water, it conducts electricity. How will you explain this statement on the basis of ionisation and how is it affected by concentration of sodium chloride?

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?