Science (English Medium) Class 11 - CBSE Question Bank Solutions for Chemistry

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

Ethyl acetate is formed by the reaction between ethanol and acetic acid and the equilibrium is represented as:

\[\ce{CH3COOH (l) + C2H5OH (l) ⇌ CH3COOC2H5 (l) + H2O (l)}\]

Write the concentration ratio (reaction quotient), Qc, for this reaction (note: water is not in excess and is not a solvent in this reaction).

Ethyl acetate is formed by the reaction between ethanol and acetic acid and the equilibrium is represented as:

\[\ce{CH3COOH (l) + C2H5OH (l) ⇌ CH3COOC2H5 (l) + H2O (l)}\]

At 293 K, if one starts with 1.00 mol of acetic acid and 0.18 mol of ethanol, there is 0.171 mol of ethyl acetate in the final equilibrium mixture. Calculate the equilibrium constant.

Ethyl acetate is formed by the reaction between ethanol and acetic acid and the equilibrium is represented as:

\[\ce{CH3COOH (l) + C2H5OH (l) ⇌ CH3COOC2H5 (l) + H2O (l)}\]

Starting with 0.5 mol of ethanol and 1.0 mol of acetic acid and maintaining it at 293 K, 0.214 mol of ethyl acetate is found after sometime. Has equilibrium been reached?

Suggest a reason as to why CO is poisonous.