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

Calculate a) ΔG°and b) the equilibrium constant for the formation of NO₂ from NO and O₂ at 298 K

\[\ce{NO(g) + 1/2 O_2 (g) <=> NO_2(g)}\]

where Δ_fG^⊝ (NO₂) = 52.0 kJ/mol

Δ_fG^⊝ (NO) = 87.0 kJ/mol

Δ_fG^⊝ (O₂) = 0 kJ/mol

Does the number of moles of reaction products increase, decrease or remain same when each of the following equilibria is subjected to a decrease in pressure by increasing the volume?

\[\ce{3Fe (s) + 4H2O (g) ⇌ Fe3O4 (s) + 4H2 (g)}\]

Compare the structures of H₂O and H₂O₂.

Predict which of the following reaction will have the appreciable concentration of reactants and products:

1. \[\ce{Cl2 (g) ⇌ 2Cl (g)}\] K_c = 5 ×10^–39
2. \[\ce{Cl2 (g) + 2NO (g) ⇌ 2NOCl (g)}\] K_c = 3.7 × 10⁸
3. \[\ce{Cl2 (g) + 2NO2 (g) ⇌ 2NO2Cl (g)}\] K_c = 1.8

The value of K_c for the reaction 3O₂ (g) ↔ 2O₃ (g) is 2.0 ×10^–50 at 25°C. If the equilibrium concentration of O₂ in the air at 25°C is 1.6 ×10^–2, what is the concentration of O₃?

The reaction, \[\ce{CO(g) + 3H2(g) ↔ CH4(g) + H2O(g)}\] is at equilibrium at 1300 K in a 1L flask. It also contains 0.30 mol of CO, 0.10 mol of H₂ and 0.02 mol of H₂O and an unknown amount of CH₄ in the flask. Determine the concentration of CH₄ in the mixture. The equilibrium constant, K_c for the reaction at the given temperature is 3.90.

What is green chemistry?

What is the relationship between the members of following pairs of structures? Are they structural or geometrical isomers or resonance contributors?

What is the relationship between the members of following pairs of structures? Are they structural or geometrical isomers or resonance contributors?

\[\begin{array}{cc}\ce{^+OH}\\||\\
\ce{H - C - OH}\end{array}\]

\[\begin{array}{cc}\ce{OH}\phantom{.}\\|\phantom{...}\\
\ce{H - C^+ - OH}\end{array}\]

Which of the following statements is correct about the reaction given below:

\[\ce{4Fe(s) + 3O2(g) -> 2Fe2O3(g)}\]

Which of the following reactions is not correct according to the law of conservation of mass.

Which of the following is not an actinoid?

The electronic configuration of gadolinium (Atomic number 64) is ______.

The elements in which electrons are progressively filled in 4f-orbital are called ______.

In the modern periodic table, elements are arranged in order of increasing atomic numbers which is related to the electronic configuration. Depending upon the type of orbitals receiving the last electron, the elements in the periodic table have been divided into four blocks, viz, s, p, d and f. The modern periodic table consists of 7 periods and 18 groups. Each period begins with the filling of a new energy shell. In accordance with the Arfbau principle, the seven periods have 2, 8, 8, 18, 18, 32 and 32 elements respectively. The seventh period is still incomplete. To avoid the periodic table being too long, the two series of f-block elements, called lanthanoids and actinoids are placed at the bottom of the main body of the periodic table.

The element with atomic number 57 belongs to ______.

In the modern periodic table, elements are arranged in order of increasing atomic numbers which is related to the electronic configuration. Depending upon the type of orbitals receiving the last electron, the elements in the periodic table have been divided into four blocks, viz, s, p, d and f. The modern periodic table consists of 7 periods and 18 groups. Each period begins with the filling of a new energy shell. In accordance with the Arfbau principle, the seven periods have 2, 8, 8, 18, 18, 32 and 32 elements respectively. The seventh period is still incomplete. To avoid the periodic table being too long, the two series of f-block elements, called lanthanoids and actinoids are placed at the bottom of the main body of the periodic table.

Which of the elements whose atomic numbers are given below, cannot be accommodated in the present set-up of the long form of the periodic table?

In the modern periodic table, elements are arranged in order of increasing atomic numbers which is related to the electronic configuration. Depending upon the type of orbitals receiving the last electron, the elements in the periodic table have been divided into four blocks, viz, s, p, d and f. The modern periodic table consists of 7 periods and 18 groups. Each period begins with the filling of a new energy shell. In accordance with the Arfbau principle, the seven periods have 2, 8, 8, 18, 18, 32 and 32 elements respectively. The seventh period is still incomplete. To avoid the periodic table being too long, the two series of f-block elements, called lanthanoids and actinoids are placed at the bottom of the main body of the periodic table.

The elements with atomic numbers 35, 53 and 85 are all ______.

Electronic configurations of four elements A, B, C and D are given below:

(A) 1s²2s²2p⁶

(B) 1s²2s²2p⁴

(C) 1s²2s²2p⁶3s¹

(D) 1s²2s²2p⁵

Which of the following is the correct order of increasing tendency to gain electron:

Illustrate by taking examples of transition elements and non-transition elements that oxidation states of elements are largely based on electronic configuration.

In both water and dimethyl ether \[\ce{(CH3 - \overset{\bullet\bullet}{\underset{\bullet\bullet}{O}} - CH3)}\], oxygen atom is central atom, and has the same hybridisation, yet they have different bond angles. Which one has greater bond angle? Give reason.