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

On the basis of the equation \[\ce{pH}\] = – log \[\ce{[H+]}\], the \[\ce{pH}\] of 10^–8 mol dm^–3 solution of \[\ce{HCl}\] should be 8. However, it is observed to be less than 7.0. Explain the reason.

Assertion (A): A solution containing a mixture of acetic acid and sodium acetate maintains a constant value of \[\ce{pH}\] on addition of small amounts of acid or alkali.

Reason (R): A solution containing a mixture of acetic acid and sodium acetate acts as a buffer solution around \[\ce{pH}\] 4.75.

Assertion (A): An aqueous solution of ammonium acetate can act as a buffer.

Reason (R): Acetic acid is a weak acid and \[\ce{NH4OH}\] is a weak base.

The solubility product constant of Ag₂CrO₄ and AgBr are 1.1 × 10^–12 and 5.0 × 10^–13respectively. Calculate the ratio of the molarities of their saturated solutions.

Equal volumes of 0.002 M solutions of sodium iodate and cupric chlorate are mixed together. Will it lead to precipitation of copper iodate? (For cupric iodate K_sp = 7.4 × 10^–8).

A person living in Shimla observed that cooking food without using pressure cooker takes more time. The reason for this observation is that at high altitude:

Physical properties of ice, water and steam are very different. What is the chemical composition of water in all the three states.

The behaviour of matter in different states is governed by various physical laws. According to you what are the factors that determine the state of matter?

Assertion (A): Three states of matter are the result of balance between intermolecular forces and thermal energy of the molecules

Reason (R): Intermolecular forces tend to keep the molecules together but thermal energy of molecules tends to keep them apart.

Assertion (A): Liquids tend to have maximum number of molecules at their surface.

Reason (R): Small liquid drops have spherical shape.

A sparingly soluble salt gets precipitated only when the product of concentration of its ions in the solution (Q_sp) becomes greater than its solubility product. If the solubility of \[\ce{BaSO4}\] in water is 8 × 10^–4 mol dm^–3. Calculate its solubility in 0.01 mol dm^–3 of \[\ce{H2SO4}\].

The solubility product of \[\ce{Al(OH)3}\] is 2.7 × 10^–11. Calculate its solubility in gL^–1 and also find out pH of this solution. (Atomic mass of \[\ce{Al = 27 u}\]).

A sparingly soluble salt having general formula \[\ce{A^{p+}_x B^{q-}_y}\] and molar solubility S is in equilibrium with its saturated solution. Derive a relationship between the solubility and solubility product for such salt.