A. Account for the following :

(i) is more acidic than

(ii) is more covalent than

B. Draw the structures of :

(i) (ii)

OR

(i) Arrange the following in the increasing order of their reducing character :

(ii) Out of He and Xe, which one can easily form compound and why?

(iii) Write the conditions to maximize the yield of ammonia in Haber’s process.

(iv) Write two uses of Chlorine gas.

(v) How can you detect the presence of gas?

A.(i) H₂Te has less bond dissociation enthalpy than H₂S . So, less energy is required to break H₂Te bond & releasing [H]⁺ is easier & hence the acidity of H₂Te is higher. Whereas, H₂S has High Bond Dissociation Energy & hence the acidity of H₂S is less.

(ii) PCl₅ is a non-polar covalent molecule because individual dipole moments of P-Cl bond cancel out each other but PCl₃ is a polar covalent molecule. Therefore, PCl₅ is more covalent than PCl₃

B. (i)

(ii)

OR

(i) Acid strength can be explained by the oxidation number of the central atom. The central atom here is Phosphorous (P).

H₃PO₄: +5

H3PO₃: +3

H3PO₂: +1

Hence, the order of reducing character is H₃PO₄>H₃PO₃>H₃PO₂

(ii) Xenon have 8 electrons in its Valence shell Due to large size of Xenon the force of attraction between the Valence shell and nucleous decreases and it forms compound like XeF6, XeOF4 etc where as He is very small in size and have more force of attraction between Valence shell and nucleous hence He cannot form compounds in ordinary conditions (at room temperature).

(iii) In accordance to Le Chatelier's principle ,low temperature will shift the equilibrium to the right because the reaction is exothermic. This gives greater yield of ammonia. Therefore a temperature of about 450°C will be optimal for the preparation of ammonia.

(iv) Chlorine is commonly used as an antiseptic and is used to make drinking water safe and to treat swimming pools. Large amounts of chlorine are used in many industrial processes, such as in the production of paper products, plastics, dyes, textiles, medicines, antiseptics, insecticides, solvents and paints.

(v) SO₂ is a colorless and pungent smell gas. It can be detected by using potassium permanganate solution. When SO₂ is passed through an acidified potassium permanganate solution, then it decolonises the solution as it reduces MnO^4- ions to Mn²⁺ ions. SO₂ give out suffocating smell which indicates its presence.