Q23 of 26 Page 1

Mr. Roy, the principal of one reputed school organized a seminar in which he invited parents and principals to discuss the serious issue of diabetes and depression in students. They all resolved this issue by strictly banning junk food in schools and introducing healthy snacks and drinks like soup, lassi, milk, etc. in school canteens. They also decided to make compulsory half an hour of daily physical activities for the students in the morning assembly. After six months, Mr. Roy conducted the health survey in most of the schools and discovered a tremendous improvement in the health of the students. After reading the above passage, answer the following questions:

(i) What are the values (at least two) displayed by Mr. Roy?


(ii) As a student, how can you spread awareness about this issue?


(iii) What are tranquilizers? Give an example.


(iv) Why is use of aspartame limited to cold foods and drinks?


(i) The two values displayed by Mr Roy are


• Caring – He was concerned about student’s health and thus took an initiative because he cares about them.


• Social service- He conducted the health survey in most of the schools and discovered a tremendous improvement in the health of the students.


(ii) Awareness can be spread by displaying posters, slogans, speeches, by conducting seminars and also encouraging others for participating in such activities so that more and more people can be aware of it.


(iii) Tranquilizers are a class of chemical compounds used for the treatment of stress, and mild or even severe mental diseases. These relieve anxiety, stress, irritability or excitement by inducing a sense of well-being. Examples are chlordiazepoxide, meprobamate, equanil, etc.


(iv) Use of aspartame is limited to cold foods and soft drinks because it is unstable at cooking temperature.


More from this chapter

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21

Give reasons for the following:

(i) Benzyl chloride is highly reactive towards the SN1 reaction.


(ii) 2-bromobutane is optically active but 1-bromobutane is optically inactive.


(iii) Electrophilic reactions in haloarenes occur slowly.


22

How do you convert the following:

(i) Aniline to phenol


(ii) Prop-1-ene to Propan-1-ol


(iii) Anisole to 2-methoxytoluene


OR


What happens when


(i) ethanol is treated with Cu at 573 K,


(ii) phenol is treated with CH3COCl / anhydrous AlCl3,


(iii) ethyl chloride is treated with NaOCH3 ?


Write chemical equations in support of your answer.


24

For the hydrolysis of methyl acetate in aqueous solution, the following results were obtained:


(a) Show that it follows pseudo first order reaction, as the concentration of water remains constant.


(b) Calculate the average rate of reaction between the time interval 20 to 40 seconds.


OR


(a) Define the following terms:


(i) Collision frequency


(ii) Rate constant (k)


(b) The rate constant of a first order reaction increases from 410-2 to 2410-2 when the temperature changes from 300 K to 350 K. Calculate the energy of activation (Ea). (log 2 = 0.301, log 3 = 0.4771, log 4 = 0.6021, log 6 = 0.7782)


25

(a) Account for the following :

(i) Bi(V) is a stronger oxidizing agent than Sb(V).


(ii) H – O – I is a weaker acid than H – O – Cl.


(iii) Bond angle decreases from H2O to H2S.


(b) Draw the structures of the following:


(i) SF4 (ii) XeF2


OR


(i) Why does PCl5 fume in moisture?


(ii) Write the name of the allotrope of sulphur which is stable at room temperature.


(iii) Chlorine water on standing loses its yellow colour. Why?


(iv) Write the disproportionation reaction of H3PO3.


(v) Complete the following equation:


F2 + H2O