Ncert Solutions Chemistry Class 11th

10.3. Assertion: The alkalimetals and their salts impart characteristiccolour to an oxidizing flame.

Reason: This heat from the flame excites the outermost orbitalelectron to a higher energy level. When the excitedelectron comes back to the ground state, thereis emission of radiation in the visible region ofthe spectrum.

10.1.Assertion: The elements of Group 2 are commonly known asthe alkaline earth metals.

Reason: Theiroxides and hydroxides are alkaline in nature and thesemetal oxides are found in the earth's crust.

What effect does a catalyst have on the equilibrium position of a reaction?
(a) A catalyst favours the formation of products
(b) A catalyst favours the formation of reactants
(c) A catalyst does not change the equilibrium position of a reaction
(d) A catalyst may favour reactants or product formation, depending upon the direction in which the reaction is written.

What effect does a catalyst have on the equilibrium position of a reaction?
(a) A catalyst favours the formation of products
(b) A catalyst favours the formation of reactants
(c) A catalyst does not change the equilibrium position of a reaction
(d) A catalyst may favour reactants or product formation, depending upon the direction in which the reaction is written.

On addition of acetate ions to an acetic acid solution, the concentration of hydrogen ions, [H⁺]

(a) Becomes zero                     (b) Is unchanged                        (c) Increases                             (d) Decreases

As the size of A increases down the group, H-A bond strength decreases and so the acid strength 

(a) Increases                                 (b) Decreases

(c) Remains constant                     (d) Becomes negligible

4.30. Which hybrid orbitals are used by carbon atoms in the following molecules?

(a) CH₃-CH₃ (b) CH₃-CH=CH₂ (c) CH₃-CH₂-OH (d) CH₃-CHO (e) CH₃COOH.

4.27. Draw diagrams showing the formation of a double bond and a triple bond between carbon atoms in C₂H₄ and C₂H₂ molecules.

4.20 The skeletal structure of CH₃COOH as shown below is correct, but some of the bonds are shown incorrectly. Write the correct Lewis structure for acetic acid.

4.14. Use Lewis symbols to show electron transfer between the following atoms to form cations and anions (a) K and S (b) Ca and O (c) Al and N.