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

How can you apply green chemistry for the following:

To avoid use of halogenated solvents in drycleaning and that of chlorine in bleaching.

For dry cleaning, in the place of tetrachloroethane, liquefied carbon dioxide with suitable detergent is an alternative solvent. What type of harm to the environment will be prevented by stopping use of tetrachloroethane? Will use of liquefied carbon dioxide with detergent be completely safe from the point of view of pollution? Explain.

If 10 volumes of dihydrogen gas reacts with five volumes of dioxygen gas, how many volumes of water vapour would be produced?

What does atomic radius and ionic radius really mean to you?

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?