Q23 of 26 Page 1

Shyam went to a grocery shop to purchase some food items. The shopkeeper packed all the items in polythene bags and gave them to Shyam. But Shyam refused to accept the polythene bags and asked the shopkeeper to pack the items in paper bags. He informed the shopkeeper about the heavy penalty imposed by the government for using polythene bags. The shopkeeper promised that he would use paper bags in future in place of polythene bags.

Answer the following :


(a) Write the values (at least two) shown by Shyam.


(b) Write one structural difference between low-density polyethene and high-density polyethene.


(c) Why did Shyam refuse to accept the items in polythene bags ?


(d) What is a biodegradable polymer? Give one example?

(a) Shyam was aware of the environment al a responsible citizen and had moral values.

(i) Shyam was aware of the hazards of polythene use by us and was willing to share the information with shopkeeper for a good cause.


(ii) Shyam told the shopkeeper about the replacement of the polythene bags by paper bags.


(b) Low-Density Polythene is branched chain structure, whereas the high-density polyethene has a linear chain structure.


(c) Shyam refused to take the items in polythene bags as polythene is nor biodegradable neither recyclable, so the one used polythene packet go to environment and get accumulated, creating hazards to the environment.


(d) Biodegradable polymers contain functional groups similar to functional groups present in biopolymers, so they get degraded in the environment by decomposers and thus are environment-friendly.


For example ploy β-hydroxybutyrate-co-β-hydroxy valerate(PHBV).


More from this chapter

All 26 →
21

Define the following with an example of each :

(a) Polysaccharides


(b) Denatured protein


(c) Essential amino acids


OR


(a) Write the product when D-glucose reacts with conc. HNO3.


D-glucose + HNO3→


(b) Amino acids show amphoteric behaviour. Why?

 22

(a) Write the formula of the following coordination compound : Iron(III) hexacyanoferrate (II)

(b) What type of isomerism is exhibited by the complex


(c) Write the hybridisation and number of unpaired electrons in the complex [CoF6 ]3- . (Atomic No. of Co = 27)

 24

(a) Give reasons:


(i) H3PO3 undergoes disproportionation reaction, but H3PO4 does not.


(ii) When Cl2 reacts with an excess of F2. ClF3 is formed and not FCl3.


(iii) Dioxygen is a gas while Sulphur is a solid at room temperature.


(b) Draw the structures of the following:


(i) XeF4


(ii) HCLO3


OR


(a) When concentrated sulphuric acid was added to n unknown salt present in a test tube a brown gas(A) was evolved. This gas intensified when copper turning were added to this test tube . On cooling, the gas (A) changed int a colourless solid(B).


(i) Identify (A) and (B).


(ii) Write the structures of (A) and (B).


(iii) Why does gas (A) change to solid on cooling?


(b) Arrange the following in the decreasing order of theirreducing character:


HF, HCl, HBr, HI


(c) Complete the following reaction:


XeF4 +SbF5→

 25

(a) Write the cell reaction and calculate the e.m.f. of the following cell at 298 K.

Sn (s ) | Sn 2+ (0.004 M )|| H+(0.020 M ) | H 2 (g )(1bar)| Pt (s)


(Given: E0 Sn+2/Sn=-0.14V )


(b) Give reasons:


(i) On the basis of E0 values, O2 gas should be liberated at anode, but it is Cl2 gas which is liberated in the electrolysis of aqueous NaCl.


(ii) The conductivity of CH3COOH decreases on dilution.


OR


(a) For the reaction


2AgCl(s) + H2(g) (1 atm) → 2Ag(s) + 2H+ + 2H+ (0.1M) + 2Cl- (0.1M),


ΔG° = -43600J at 35° C.


Calculate the e.m.f. of the cell.


[log 10-n = -n]
(b) Define fuel cell and write its two advantages.