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

What do you understand by isoelectronic species? Name a species that will be isoelectronic with the following atom or ion:-

F^-

What do you understand by isoelectronic species? Name a species that will be isoelectronic with the following atom or ion:-

Ar

What do you understand by isoelectronic species? Name a species that will be isoelectronic with the following atom or ion:-

Mg²⁺

What do you understand by isoelectronic species? Name a species that will be isoelectronic with the following atom or ion:-

Rb⁺

Consider the following species:-

N^3–, O^2–, F^–, Na⁺, Mg²⁺ and Al³⁺

Arrange them in the order of increasing ionic radii.

Consider the following species:-

N^3–, O^2–, F^–, Na⁺, Mg²⁺ and Al³⁺

What is common in them?

Explain why cations are smaller and anions larger in radii than their parent atoms?

The size of isoelectronic species — F^-, Ne and Na⁺ is affected by ______.

Explain the important aspects of resonance with reference to the `"CO"_3^(2-)` ion.

H₃PO₃ can be represented by structures 1 and 2 shown below. Can these two structures be taken as the canonical forms of the resonance hybrid representing H₃PO₃? If not, give reasons for the same.

(1)	(2)

Write the resonance structure for SO₃.

Write the resonance structures for NO₂.

Write the resonance structures for `"NO"_3^(-)`.

At 0°C, the density of a certain oxide of a gas at 2 bar is same as that of dinitrogen at 5 bar. What is the molecular mass of the oxide?

The pressure of 1 g of an ideal gas A at 27 °C is found to be 2 bar. When 2 g of another ideal gas B is introduced in the same flask at the same temperature the pressure becomes 3 bar. Find a relationship between their molecular masses.

The drain cleaner, Drainex contains small bits of aluminum which react with caustic soda to produce dihydrogen. What volume of dihydrogen at 20 °C and one bar will be released when 0.15g of aluminum reacts?

The density of a gas is found to be 5.46 g/dm³ at 27 °C at 2 bar pressure. What will be its density at STP?

How much time would it take to distribute one Avogadro number of wheat grains, if 10¹⁰ grains are distributed each second?

Comment on the thermodynamic stability of NO_(g), given

\[\ce{1/2 N_2 (g) + 1/2 O2(g) → NO(g)}\]; Δ_rH^θ = 90 kJ mol^–1

\[\ce{NO(g) +1/2 O2(g) → NO2(g)}\] : Δ_rH^θ= –74 kJ mol^–1

Why is Wurtz reaction not preferred for the preparation of alkanes containing odd number of carbon atoms? Illustrate your answer by taking one example