Class 11 Chemistry Model Question Set D

The number of orbitals present in a subshell having is:

a. 2

b. 3

c. 5

d. 7

The number of atoms present in 0.5 mole of helium is:

a.

b.

c.

d.

Which of the following elements has the largest atomic radius?

a. Li

b. Na

c. K

d. Rb

Which molecule has a linear shape?

a.

b.

c.

d.

The oxidation number of manganese in is:

a. +2

b. +4

c. +6

d. +7

At constant temperature, if the pressure of a fixed mass of gas is doubled, its volume becomes:

a. Double

b. Half

c. Four times

d. Unchanged

For an endothermic forward reaction, increasing temperature:

a. Shifts equilibrium towards reactants

b. Shifts equilibrium towards products

c. Has no effect on equilibrium

d. Stops the reaction

Which allotrope of sulphur is stable at room temperature?

a. Monoclinic sulphur

b. Rhombic sulphur

c. Plastic sulphur

d. Colloidal sulphur

Which ore is concentrated by froth flotation?

a. Haematite

b. Bauxite

c. Zinc blende

d. Cinnabar

The functional group present in aldehydes is:

a.

b.

c.

d.

The catalyst commonly used in the Haber process is:

a. Nickel

b. Platinum

c. Finely divided iron

d. Vanadium pentoxide

(a) Define percentage yield. [1]

(b) When 10 g of calcium carbonate is heated strongly, calculate the mass of calcium oxide produced. [3]

𝐶 𝑎 𝐶 𝑂 3 → Δ 𝐶 𝑎 𝑂 + 𝐶 𝑂 2 CaCO 3

Δ CaO+CO 2

(c) State one reason why the actual yield of a chemical reaction may be less than its theoretical yield. [1]

(a) State Aufbau's principle. [1]

(b) Write the electronic configuration of iron (atomic number 26) and identify the number of unpaired electrons in its ground state. [2]

(c) Explain why the atomic radius of chlorine is smaller than that of sodium. [2]

(a) Define dipole moment. [1]

(b) Explain why 𝐶 𝑂 2 CO 2 is non-polar although its C=O bonds are polar. [2]

(c) Describe the shape and hybridization of 𝐶 𝐻 4 CH 4 . [2]

(a) Define reducing agent. [1]

(b) Calculate the oxidation number of chromium in . [2]

(c) Explain why oxidation and reduction always occur simultaneously. [2]

(a) State Charles's law. [1]

(b) A balloon has a volume of 3 L at 300 K. Calculate its volume when heated to 450 K at constant pressure. [2]

(c) Explain the significance of the van der Waals constants and . [2]

(a) Define homogeneous equilibrium. [1]

(b) Write the equilibrium constant expression for the following reaction. [2]

(c) Explain the effect of increasing the concentration of oxygen on the equilibrium position. [2]

(a) Define buffer solution. [1]

(b) What are acidic and basic buffer solutions? Give one example of each. [2]

(c) Calculate the pH of a NaOH solution at 25°C. [2]

(a) What is gangue? [1]

(b) Explain the principle of electrolytic refining of copper. [2]

(c) Write two chemical properties of chlorine with balanced equations. [2]

(a) Define chain isomerism. [1]

(b) Write the structural formulae of two chain isomers of . [2]

(c) Explain Markovnikov's rule with a suitable chemical equation. [2]

An unsaturated hydrocarbon B upon treatment with hydrogen bromide produces compound C. Compound C reacts with sodium metal in the presence of organic ether and produces compound D of molecular formula C₆H₁₄.

i. Give the chemical equations for the conversion of compound B to compound C and compound C to compound D. [2]

ii. Write down the IUPAC name of compound C and D. [2]

iii. Give the structural formula of positional isomer of compound C. [1]

(a) Derive the ideal gas equation from Boyle's law, Charles's law and Avogadro's law. [4]

(b) Calculate the volume occupied by 2 moles of an ideal gas at 27°C and 2 atm pressure. [2]

Given:

(c) Why do gases behave more ideally at high temperature and low pressure? [2]

(a) Describe the laboratory preparation of chlorine gas with a balanced chemical equation and labelled diagram. [3]

(b) Explain the bleaching action of chlorine in the presence of moisture. [2]

(c) Write balanced equations for the reactions of chlorine with: [2]

i. Cold dilute sodium hydroxide

ii. Hydrogen

(d) Mention one use of chlorine in public health. [1]

(a) Explain the extraction of aluminium from bauxite by the electrolytic process. [4]

(b) Write the electrode reactions occurring during the electrolysis of alumina dissolved in molten cryolite. [2]

(c) State two functions of cryolite in the extraction of aluminium. [2]

(a) Explain the preparation of ethyne from calcium carbide with a balanced equation. [2]

(b) Write chemical equations for the reactions of ethyne with: [3]

i. Hydrogen (complete hydrogenation)

ii. Bromine (excess)

iii. Hydrogen chloride (one mole)

(c) What is aromaticity? State one condition for a compound to be aromatic. [2]

(d) Why is benzene more stable than an ordinary cyclohexatriene structure? [1]