Q25 of 26 Page 1

(a) Account for the following:

(i) BiH3 is the strongest reducing agent in Group 15 elements hydrides.


(ii) Cl2 acts as a bleaching agent.


(iii) Noble gases have very low boiling points.


(b) Draw the structures of the following:


(i) H4P2O7


(ii) XeOF4


OR


(a) Although nitrogen and chlorine have nearly same electronegativity yet nitrogen forms hydrogen bonding while chlorine does not. Why?


(b) What happens when F2 reacts with water?


(c) Write the name of the gas evolved when Ca3P2 is dissolved in water.


(d) Write the formula of a noble gas species which is isostructural with IBr2-.


(e) Complete the equation: [Fe(H2O)6]2+ + NO →


(a)


(i) BiH3 is the strongest reducing agent in Group 15 elements hydrides because stability of hydrides decreases down the group as the size of cations increases and hence reducing character of hydrides increases.


(ii) Cl2 acts as a bleaching agent because it liberates nascent oxygen when reacted with water and that nascent oxygen converts colored substance into colorless substance.


Cl2 + H2O → HCl + HOCl


HOCl → HCl + (O)


Colored substance + (O) → colorless


(iii) Noble gases have very low boiling points because only type of interatomic interactions present in these elements is weak dispersion forces.


(b)


(i) H4P2O7



(ii) XeOF4



OR


(a) Although nitrogen and chlorine have nearly same electronegativity yet nitrogen forms hydrogen bonding while chlorine does not because size of nitrogen is smaller than chlorine because of which electron density per unit volume on N atom is higher than that of Cl atom.


(b) It oxidses H2O to O2.


2F2 + 2H2O → O2 + 4H+ + 4F-


(c) Gas evolved when Ca3P2 is dissolved in water is phosphine.


Ca3P2 + 6H2O → 3Ca(OH)2 + 2PH3


(d) Noble gas species which is isostructural with IBr2- is XeF2. Both have 2 bond pairs and 3 lone pairs and form a linear structure.


(e) [Fe(H2O)6]2+ + NO → [Fe(H2O)5(NO)]2+ + H2O


(brown ring)


More from this chapter

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22

Define the following terms:

(a) Tranquilizer


(b) Anionic detergent


(c) Disinfectant


 23

After watching a programme on TV about the presence of carcinogens (cancer causing agents) Potassium bromate and Potassium iodate in bread and other bakery products, Veena, a class XII student, decided to make others aware about the adverse effects of these carcinogens in foods. She consulted the school principal and requested him to instruct the canteen contractor to stop selling sandwiches, pizzas, burgers and other bakery products to the students. The principal took an immediate action and instructed the canteen contractor to replace the bakery products with some proteins and vitamins-rich food like fruits, salads, sprouts, etc. The decision was welcomed by the parents and students.

After reading the above passage, answer the following questions:


(a) What are the values (at least two) displayed by Veena?


(b) Which polysaccharide component of carbohydrates is commonly present in bread?


(c) Write the two types of secondary structures of proteins.


(d) Give two examples of water soluble vitamins.


 24

(a) A first order reaction is 75% completed in 40 minutes. Calculate its t1/2.

(b) Predict the order of the reaction in the given plots:


2019-11-29.png


Where, [R]o is the initial concentration of reactant. (Given: log 2 = 0.3010, log 4 = 0.6021)


OR


The following data were obtained for the reaction:


2 NO + O2→2 NO2



(a) Find the order of reaction with respect to NO and O2.


(b) Write the rate law and overall order of reaction.


(c) Calculate the rate constant (k).


 26

Write the structures of A, B, C, D and E in the following reactions:


OR


(a) Write the structures of the main products when benzene diazonium chloride reacts with the following reagents:


(i) CuCN


(ii) CH3CH2OH


(iii) Cu / HCl


(b) Arrange the following in the increasing order of their basic strength: CH3NH2, (CH3)2NH, C6H5NH2, C6H5CH2NH2


(c) Write one chemical test to distinguish between Aniline and Ethyl amine.