Q23 of 26 Page 1

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.


(a) The values displayed by Veena are


Caring – she was concerned about other student’s health and thus took an initiative because she cares about them.


Social awareness- she used the knowledge that she acquired through TV and spread awareness about the issue so that everybody could acquire that knowledge.


(b) Polysaccharide component of carbohydrates which is commonly present in bread are starch and glycogen.


(c) Two types of secondary structures of proteins are


Helix: all possible hydrogen bonds are twisted into a right handed screw (helix) with the –NH group of each amino acid residue hydrogen bonded to the C=O of an adjacent turn of the helix.


Pleated sheet: all peptide chains are stretched out to nearly maximum extension and then laid side by side which are held together by intermolecular hydrogen bonds. The structure resembles the pleated folds of drapery and therefore is known as β-pleated sheet.


(d) Examples of water soluble vitamins are vitamin B (except vitamin B12) and vitamin C.


More from this chapter

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21

Account for the following:

(a) CuCl2 is more stable than Cu2Cl2.


(b) Atomic radii of 4d and 5d series elements are nearly same.


(c) Hydrochloric acid is not used in permanganate titrations.


 22

Define the following terms:

(a) Tranquilizer


(b) Anionic detergent


(c) Disinfectant


 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).


 25

(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 →