94420 + Interview Questions in Chemistry in Class 12

1.	Assertion (A) : Receptors are crucial to body's communication process. Reason (R) : Receptors are proteins.
Answer» ASSERTION and reason both are correct STATEMENT but reason does not EXPLAIN assertion. Assertion and reason both are correct and reason EXPLAINS the assertion. Both assertion and reason are wrong statement. Assertion is correct statement reason is wrong statement. Solution :Assertion and reason both are correct statement but reason does not explain assertion

Discussion

2.	Assertion (A) : Receptor proteins show selectivity for one chemical messenger over the other. Reason (R) : Chemical messenger binds to the receptor site and inhibits its natural function.
Answer» ASSERTION and reason both are correct statement but reason does not explain assertion. Assertion and reason both are correct and reason explains the assertion. Both assertion and reason are wrong statement. Assertion is correct statement reason is wrong statement. Solution :Assertion is correct statement reason is wrong statement. Correct reason : Chemical messenger binds the RECEPTOR SITE and gives the message to the CELL without entering the cell.

Discussion

3.	Assertion (A) : Reactivity of ketones is more than aldehydes. Reason ( R ) : The carbonyl carbon of ketones is less electrophilic as compared to aldehydes.
Answer» Both Assertion (A) and REASON ( R ) are correct statements, and Reason ( R ) is the correct explanation of the Assertion (A). Both Assertion (A) and Reason ( R ) are correct statements, but Reason ( R ) is not the correct explanation of the Assertion (A). Assertion (A) is correct, but Reason ( R ) is incorrect statement. Assertion (A) is incorrect, but Reason ( R ) is correct statement. Answer :D

Discussion

4.	Assertion (A) : Reactions taking place in one step are called elementary reactions. Reason (R ) : When a sequence of elementary reactions gives us the products, the reactions are called complex reactions.
Answer» Both Assertion (A) and REASON (R ) are CORRECT statements, and Reason (R ) is the correct EXPLANATION of the Assertion (A). Both Assertion (A) and Reason (R ) are correct statements, but Reason (R ) is not the correct explanation of the Assertion (A). Assertion (A) is correct, but Reason (R ) is incorrect statement. Assertion (A) is incorrect, but Reason (R ) is correct statement. Answer :B

Discussion

5.	Assertion (A): Reaction between (Me_(3)CONa) (sodium ter-butoxide) and ethyliode (C_(2)H_(5)I) does not produce an ether.Reason (R): Sodium ter-butoxide is a very strongbase but is not a nucleophile.
Answer» Both `(A)` and `(R)` are true and `(R0` is the CORRECT EXPLANATION of `(A)`. Both `(A)` and `(R)` are true but `(R)` is not the correct explanation of `(A)`. `(A) is true but `(R)` is FALSE. `(A) is falsebut `(R)` is true. Solution :It produces ALKENE

Discussion

6.	Assertion (A) : RCl is hydrolysed to ROH slowly but reaction is rapid if catalytic amounts of KI are added to the reaction mixture. Reaction (R ) : I^(-) is a powerful nucleophile which reacts rapidly with RCl to form RI. I^(-) is a batter leaving group than Cl^(-) and RI is hydrolysed rapidly to ROH.
Answer» Both A and R are true and R is the CORRECT EXPLANATION of A Both A and R are true but R is not a correct explanation of A A is true but R is true A is false but R is true Answer :A

Discussion

7.	Assertion (A) Rayon is a semisynthetic polymer and is taken as a better choice than cotton fabric. Reason (R ) Mechanical and aesthetic properties of cellulose can be improved by Acetylation
Answer» If both ASSERTION and reason are TRUEAND reason is the CORRECT explanationof assertion . If both assertion and reason are true but reason is not the correct explanationof assertion . If assertion is true but reason is FALSE. If both assertion and reason are false. Answer :A

Discussion

8.	Assertion (A) : Rayon is a semisynthetic polymer and is taken as a better choice than cotton fabric. Reason (R) : Mechanical and aesthetic properties of cellulose can be improved by acetylation.
Answer» ASSERTION and reason both are correct statements but reason does not explain assertion. Assertion and reason both are correct statements and reason explain the assertion. Both assertion and reason are wrong statements. Assertion is correct statement and reason is wrong statement. Solution :Assertion and reason both are correct statements and reason explain the assertion. RAYON is a semisynthetic POLYMER and it is taken as a better CHOICE than cotton fabric because mechanical and AESTHETIC properties of cellulose can be improved by acetylation.

Discussion

9.	Assertion : A rate of hydrolysis of methyl chloride to methanol is higher in DMF than in water. Reason : Hydrolysis of methyl chloride follows second order kinetics.
Answer» if both assertion and REASON are TRUE and the reason is the correct EXPLANATION of the assertion If both assertion and reason are true but reason is not the correct explanation of the assertion. If assertion is true but reason is false If the assertion and reason both are false Answer :C

Discussion

10.	Assertion (A) : Rate of reaction normally increases by a factor of 2 to 3 for every 10^(@) rise in temperature. Reason (R ) : Increase of temperature increasesthe number of collisions .
Answer» Both ASSERTION (A) and REASON (R ) are correct statements, and Reason (R ) is the correct explanation of the Assertion (A). Both Assertion (A) and Reason (R ) are correct statements, but Reason (R ) is not the correct explanation of the Assertion (A). Assertion (A) is correct, but Reason (R ) is incorrect STATEMENT. Assertion (A) is incorrect, but Reason (R ) is correct statement. Answer :A

Discussion

11.	Assertion (A): Quaternary structure of proteins represents overall folding of polypeptide chains. Reason (R) : DNA contains four bases, adenine, guanine, cytosine and thymine.
Answer» Both ASSERTION (A) and REASON (R) are CORRECT STATEMENTAND Reason (R) is the correctexplanationof the Assertion (A). Both Assertion (A) and Reason (R) are correctstatements, but Reason(R) is notthe correctexplanation of the Assertion (A). Assertion (A) is correct, but Reason(R) is incorrect statement Assertion (A) is incorrect , but Reason (R) is correct statement. Answer :D

Discussion

12.	Assertion (A) : [Pt(en)_(2)Cl_(2)]^(2+) complex is less stable than [Pt(NH_(3))_(4)Cl_(2)]^(2+) complex. Reason ( R ) : [Pt(en)_(2)Cl_(2)]^(2+) complex shows chelate effect.
Answer» Both Assertion (A) and REASON ( R ) are correct statements, and Reason ( R ) is the correct EXPLANATION of the Assertion (A). Both Assertion (A) and Reason ( R ) are correct statements, but Reason ( R ) is not the correct explanation of the Assertion (A). Assertion (A) is correct, but Reason ( R ) is INCORRECT statement. Assertion (A) is incorrect, but Reason ( R ) is correct statement. Answer :D

Discussion

13.	Assertion (A) : Protons are better projectilesthan neutrons. Reason (R) : The neutrons being neutral do not experience repulsion from positively charged nucleus.
Answer» If both `(A)` and `(R)` are CORRECT , and `(R)` is the correct EXPLANATION of `(A)` If both `(A)` and `(R)` are correct, but (R) is not the correct explanation of `(A)` If `(A)` is correct, but `(R)` is incorrect. If both `(A)` and `(R)` are incorrect. Answer :D

Discussion

14.	Assertion (A) : Propene (CH_(3)CH = CH_(2)) undergoes allylic substitution. Reason (R) : CH_(2) = CHCH_(2) (allylic) free radical is stabilised by resonance.
Answer» ANSWER :A

Discussion

15.	Assertion (A) : Primary amines with three or more carbon atoms are liquids. Reason (R) : The intermolecular association is more in primary amines than in secondary amines.
Answer» Both Assertion (A) and REASON (R) are correct statements, and Reason (R) is the correct explanation of the Assertion (A). Both Assertion (A) and Reason (R) are correct statements, but Reason (R) is not the correct explanation of the Assertion (A). Assertion (A) is correct, but Reason (R) is INCORRECT statement. Assertion (A) is incorrect, but Reason (R) is correct statement. Answer :B

Discussion

16.	Assertion (A) : Pressure cooker reduces time for cooking.Reason (R ) : In pressure cooker boiling point get increased.
Answer» ASSERTION and reason both are correct STATEMENTS and reason is correct explanation for assertion. Assertion and reason both are correct statements but reason is not correct explanation for assertion. Assertion is correct STATEMENT but reason is wrong statement. Assertion and reason both are INCORRECT statements. Answer :B

Discussion

17.	Assertion (A) : Preservative are added to food items. Reason (R) : Preservatives inhibit the growth of microorganisms.
Answer» Assertion and REASON both are correct STATEMENT but reason does not EXPLAIN assertion. Assertion and reason both are correct and reason explains the assertion. Both assertion and reason are wrong statement. Assertion is correct statement reason is wrong statement. Solution :Assertion and reason both are correct and reason explains the assertion.

Discussion

18.	Assertion (A) : Presence of a nitro group at ortho or para position increases the reactivity of haloarenes towards nucleophilic substitution.Reason (R ) : Nitro group, being an electron withdrawing group decreases the electron density over the benzene ring.
Answer» ASSERTION and reason both are CORRECT and reason is correct EXPLANATION of assertion. Assertion and reason both are WRONG statements. Assertion is correct but reason is wrong statement. Assertion is wrong but reason is correct statement. ANSWER :A

Discussion

19.	Assertion (A): Preparation of flourine came across number of difficulties Reason: R: It attacks all materials which are used in the preparation (glass, carbon, H_(2)O, metals)
Answer» A & R are TRUE R is CORRECT explanation of A A & R are true, R is not correct explanation of A A is true, but R is FALSE A is false, but R is true Solution :Conceptual

Discussion

20.	Assertion (A) : Precipitation of silver chloride by mixing of silver nitrate and sodium chloride solutions is an instantaneous reaction. Reason (R ) : Hydrolysis of starch to give glucose occurs with the very slow speed.
Answer» Both ASSERTION (A) and Reason (R ) are correct STATEMENTS, and Reason (R ) is the correct explanation of the Assertion (A). Both Assertion (A) and Reason (R ) are correct statements, but Reason (R ) is not the correct explanation of the Assertion (A). Assertion (A) is correct, but Reason (R ) is incorrect statement. Assertion (A) is incorrect, but Reason (R ) is correct statement. Answer :C

Discussion

21.	Assertion (A) : Potassium permanganate forms dark purple crystals which are isostructural with those of KClO_(3). Reason (R) : MnO_(4)^(-) ions and ClO_(4)^(-) ions possess tetrahedral structures.
Answer» Both Assertion (A) and REASON (R) are CORRECT statements, and Reason (R) is the correct explanation of the Assertion (A). Both Assertion (A) and Reason (R) are correct statements, but Reason (R) is not the correct explanation of the Assertion (A). Assertion (A) is correct, but Reason (R) is incorrect STATEMENT. Assertion (A) is incorrect, but Reason (R) is correct statement. ANSWER :A

Discussion

22.	Assertion (A): Powered calcium carbonate reacts much faster with dilute HCI then with the same mass of CaCO_3as marble. Reason : For a given mass of a reactant , when the particle size decrease, surface area increases Increase in surface area of the reaction leads to more Collisions per litre per second and hence the rate of the reaction also increase
Answer» Both A and R are CORRECT and R is the correct EXPLANATION of A Both A and R are correct but R is not the correct explanation of A A is correct but R is WRONG A is wrong but R is correct ANSWER :a

Discussion

23.	Assertion (A) : Potassium ferro thiocyanate answers the presences of Fe^(3+), K^(+) and SCN^(-) ions. Reason (R ) : The complex ion in coordination compound does not loose its identify and never dissociate to give simple ions.
Answer» Both A and R are CORRECT and R is the correct EXPLANATION of A. Both A and R are correct but R is not the correct explanation of A. A is WRONG but R is correct Both A and R are wrong Answer :C

Discussion

24.	Assertion (A) : Polytetrafluoroethene is used in making non-stick cookwares. Reason (R) : Fluorine has highest electro- negativity.
Answer» ASSERTION and reason both are correct statements but reason does not EXPLAIN assertion. Assertion and reason both are correct statements and reason explain the assertion. Both assertion and reason are wrong statements. Assertion is correct statement and reason is wrong statement. Solution :Assertion and reason both are correct statements but reason does not explain assertion. Polytetrafluoroethene (teflon) is USED in making non-stick COOKWARES because it is chemically inert, thermally stable and RESISTANT to attack by corrosive reagents.

Discussion

25.	Assertion : A positive catalyst increases the rate of reaction. Reason : A positive catalyst alters reaction mechanism and decreases activation energy.
Answer» Both assertion and REASON are TRUE and reason is the correct EXPLANATION of assertion. Both assertion and reason are true but reason is not the correct explanation of assertion. Assertion is true but reason is FALSE. Both assertion and reason are false. Answer :A

Discussion

26.	Assertion (A): Polymers like Buna-S, Buna-N and Neoprene are elastomeric polymers. Reason (R) In polymers like Buna-S and Buna-N, the polymer chains are held togetherby weakest intermolecular forces which allow the polymer to be stretched.
Answer» Both Assertion (A) and Reason (R) are correct STATEMENTS, and Rerson (R) is the correct explanation of the Assertion (A) Both Assertion (A) and Reson (R) are correct statements, but Reson (R) is not the correct explanation of the Assertion (A) Assertion (A) is correct, but Reason (R) is INCORRECT statement. Assertion (A) is incorrect, but Reason (R) is correct statement. Answer :A

Discussion

27.	Assertion (A): Polyamides and polyesters are used as fibres. Reason (R) : Bakelite and urea-formaldehyde are thermoplastic polymers.
Answer» Both ASSERTION (A) and Reason (R) are correct statements, and Rerson (R) is the correct explanation of the Assertion (A) Both Assertion (A) and Reson (R) are correct statements, but Reson (R) is not the correct explanation of the Assertion (A) Assertion (A) is correct, but Reason (R) is incorrect statement. Assertion (A) is incorrect, but Reason (R) is correct statement. ANSWER :C

Discussion

28.	Assertion (A) : Polyester and nylon are examples of linear polymers . Reason (R) : Styron is obtained by polymerisation of styrene in thepresenceof benzoyl perodxide.
Answer» Both Assertion (A) and REASON (R) arecorrect STATEMENT and Reason (R) is the correct explanationof the Assertion(A). Both Assertion (A) and Reason (R) are correct statement ,but Reason (R) is NOTTHE correct explanationof the Assertion (A) Assertion (A) is correct, but Reason (R) isincorrect statement Assertion (A) is INCORRECT , but Reason (R) is correct statement. Answer :B

Discussion

29.	Assertion (A) : Polyamides are best used as fibres because of high tensile strength. Reason (R) : Strong intermolecular forces (like hydrogen bonding within polyamides) lead to close packing of chains and increase the crystalline character, hence, provide high tensile strength to polymers.
Answer» ASSERTION and reason both are correct statements but reason does not explain assertion. Assertion and reason both are correct statements and reason explain the assertion. Both assertion and reason are WRONG statements. Assertion is correct statement and reason is wrong statement. Solution :Assertion and reason both are correct statements and reason explain the assertion. Polyamides are best used as fibres because of high tensile STRENGTH. This is due to strong intermolecular forces (like hydrogen bonding within polyamides) lead to close packing of chains and INCREASES the crystalline character, hence, provide high tensile strength.

Discussion

30.	Assertion (A): Platinised asbestos is a better adsorbent than platinum block. Reason (R): Higher the surface area, higher is the amount adsorbed. In platinum coated asbestos the surface area is more and so it act as a better adsorbent.
Answer» Both A and R are CORRECT and R is the correct EXPLANATION of A. Both A and R are WRONG. A is correct but R is wrong. A is wrong but R is correct. Answer :A

Discussion

31.	Assertion (A): Physical adsorption occurs at low temperature. Reason (R) : In physical adsorption, weak Van der Waals force of attraction exist. Other weak forces exist in physical adsorption are dipole-dipole interaction and dispersion forces. As these forces are weak, heat of adsorption is low.
Answer» Both A and R are CORRECT but R is not correct EXPLANATION of A. Both A and R are correct and R is the correct explanation of A. Both A and R are wrong. A is correct but R is wrong. Answer :B

Discussion

32.	Assertion (A) : Phosphorus chlorides (tri and penta) are preferred over thionyl chloride for the preparation of alkyl chlorides from alcohols. Reason (R) : Phosphorus chlorides give pure alkyl hakides.
Answer» (A) and (R) both are correct statement and (R) is correct EXPLANATION for (A) (A) and (R) both are correct statement but (R) is not correct explanation for (A) (A) is correct statement but (R) is wrong statement. (A) and (R) both are incorrect statement. Solution :Hint: Thionyl chloride is preferred over phosphorus chlorides for the PREPARATION of ALKYL chlorides from alcohols BECAUSES `SOCl_(2)` gives pure alkyl chlorides.

Discussion

33.	Assertion (A) : Phosphorus chlorides (tri and penta) are preferred over thionyl chloride for the preparation of alkyl chlorides from alcohols. Reason (R ) : Phosphorus chlorides give pure alkyl halides.
Answer» Assertion and reason both are correct and reason is correct explanation of assertion. Assertion and reason both are WRONG STATEMENTS. Assertion is correct but reason is wrong STATEMENT. Assertion is wrong but reason is correct statement. ANSWER :B

Discussion

34.	Assertion (A) : Phenols are stronger acids than alcohols. Reason (R ) : Phenol exhibits resonance in which the phenoxide ion gets stabilised.
Answer» Both ASSERTION (A) and Reason (R) are correct STATEMENTS, and Reason (R) is the correct EXPLANATION of the Assertion (A). Both Assertion (A) and Reason (R) are correct statements, but Reason (R) is not the correct explanationof the Assertion (A). Assertion (A) is correct, but Reason (R) is incorrect statement. Assertion (A) is incorrect, but Reason (R) is correct statement. Answer :A

Discussion

35.	Assertion (A): Phenol on nitration with Conc. HNO_(3) and H_(2)SO_(4) give a mixture of o and p-nitro phenol. Reason (R): -OH group is deactivating group.
Answer» (A) and (R) are true and (R) is the CORRECT explanation of (A). Both (A) and (R) are true but (R) does not EXPLAIN (A) (A) is true but (R) is false Both (A) and (R) are false ANSWER :D

Discussion

36.	Assertion (A) : Phenol on oxidation with Na_(2)Cr_(2)O_(7) and H_(2)SO_(4) gives benzoquinone. Reason (R) : Intramolecular hydrogen bonding occurs in o-nitrophenol.
Answer» Both ASSERTION (A) and REASON (R) are correct statements, and Reason (R) is the correct explanation of the Assertion (A). Both Assertion (A) and Reason (R) are correct statements, but Reason (R) is not the correct explanationof the Assertion (A). Assertion (A) is correct, but Reason (R) is incorrect statement. Assertion (A) is incorrect, but Reason (R) is correct statement. Answer :B

Discussion

37.	Assertion: Phenol is more acidic than ethanol Reason: Phenoxide ion is resonance stablized
Answer» (A) and (R) are true and (R) is the correct EXPLANATION of (A). Both (A) and (R) are true but (R) does not EXPLAIN (A) (A) is true but (R) is FALSE Both (A) and (R) are false Answer :A

Discussion

38.	Assertion (A): Phenol give o- and p-nitrophenol on nitration with conc. HNO_(3) and H_(2)SO_(4) mixture. Reason (R) : -OH group in phenol is o- and p-directing.
Answer» Assertion and reason both are correct statements and reason explains the assertion. Both assertion and reason are wrong statements. Assertion is correct STATEMENT and reason is wrong statement. Assertion is wrong statement and reason is correct statement. Solution :PHENOL with conc. `HNO_(3)` forms 2,4,6-tri NITROPHENOL.

Discussion

39.	Assertion (A) : Phenol forms 2,4,6-tri bromophenol on treatment with Br_(2) in carbon disulphide at 273 K. Reason (R) : Bromine polarizes carbon disulphide
Answer» Assertion and reason both are correct statements and reason explains the assertion.<BR>Both assertion and reason are wrong statements. Assertion is correct statement and reason is wrong statement. Assertion is wrong statement and reason is correct statement. Solution :Phenol forms 2,4,6-tribromophenol on treatment with `Br_(2)//H_(2)O`. In phenols, the POLARIZATION of BROMINE takes place EVEN in absence of LEWIS acids.

Discussion

40.	Assertion (A) : Ph overset (o+) (N_2) Br^(Θ) is more acidic thanNH_4 Br. Reason (R ) : Ph overset (o+)(N)H_(3) (anilinum ion ) is resonance stabilinsed .
Answer» If both (A) and (R ) ar TRUE, and (R ) is the CORRECT explanation of (A). If both (A) and (R ) are true , and (R ) is not the correct explanation of (A). If (A) is true , but (R ) is FALSE . If both (A) and (R ) are false . Solution :`NBH_2` is STRONGER base than aniline , therfore , the cojugate acid of aniline (i.e., `Ph overset (o+) (N) H_3)` is more acidic than the conjugate acid of `NH_3` (i.e, `overset (o+) (N) H_4` ion).

Discussion

41.	Assertion (A): PhBr is less reactive thanC_(2)H_(5)Br towards SN reactions. Reason (R):The forces of attrafction between RX and H_(2)O molecules are weaker than thosepresent betweenthe molecules of RX and water molelcules separate,u.
Answer» Both `(A)` and `(R)` are true and `(R0` is the CORRECT explanation of `(A)`. Both `(A)` and `(R)` are true but `(R)` is not the correct explanation of `(A)`. `(A) is true but `(R)` is false. `(A) is falsebut `(R)` is true. Solution :Correct explanation: Due to RESONANCE `(C-Br)` bond in `PhBr` is a little stronger than `(C-Br)` bond in `C_(2)H_(5)Br`

Discussion

42.	Assertion (A) : Permanent gases like H,,N, and 0, cannot be adsorbed readily. Reason (R) : Permanent gases having low critical temperature and adsorbed slowly.
Answer» Both A and R are wrong. A is CORRECT and R is the correct EXPLANATION of A. A is wrong but R is correct. A is correct but R is wrong. ANSWER :B

Discussion

43.	Assertion (A) Penicillin (G) is an antihistamine. Reason (R) Penicillin (G) is effective against gram positive as well as gram negative bacteria.
Answer» If both assertion and REASON are trueand reason is the correct explanationof assertion . If both assertion and reason are true but reason is not the correct explanationof assertion . If assertion is true but reason is FALSE. If both assertion and reason are false. Solution :PENICILLIN (G) is an ANTIBIOTIC and is effective against some gram positive BACTERIA.

Discussion

44.	Assertion (A) : Penicillin (G) is an antihistamine. Reason (R) : Penicillin (G) is effective against gram positive as well as gram negative bacteria.
Answer» ASSERTION and REASON both are CORRECT statement but reason does not explain assertion. Assertion and reason both are correct and reason explains the assertion. Both assertion and reason are WRONG statement. Assertion is correct statement reason is wrong statement. Solution :Both assertion and reason are wrong statement. Correct assertion : Penicillin (G) is an antibiotic correct reason penicillin is effective against some gram positive bacteria.

Discussion

45.	Assertion (A) : Pauling was the first to formulate his ideas about the structure of coordination compounds. Reason (R) : In coordination compounds, metals show two types of linkages, primary and secondary.
Answer» Both Assertion (A) and Reason (R) are CORRECT STATEMENTS, and Reason (R) is the correct explation of the Assertion (A). Both Assertion (A) and Reason (R) are correct statements, but Reason (R) is not the correct explation of the Assertion (A). Assertion (A) is correct, but Reason (R) is INCORRECT statement. Assertion (A) is incorrect, but Reason (R) is correct statement. Answer :C

Discussion

46.	Assertion (A) : Packing efficiency of hcp and ccp structures is 74%. Reason (R) : If the number of close packed spheres is N, then number of tetrahedral voids is N.
Answer» Both ASSERTION (A) and Reason (R) are CORRECT statements, and Reason (R) is the correct explanation of the Assertion (A). Both Assertion (A) and Reason (R) are correct statements, but Reason (R) is not the correct explanation of the Assertion (A). Assertion (A) is correct, but Reason (R) is INCORRECT statement. Assertion (A) is incorrect, but Reason (R) is correct statement. Answer :C

Discussion

47.	Assertion (A) : p-nitrophenol is more acidic than phenol Reason (R) : Nitro group helps in the stabilisation of the phenoxide ion by dispersal of negative charge due to resonance.
Answer» ASSERTION and reason both are CORRECT statements and reason EXPLAINS the assertion. Both assertion and reason are wrong statements. Assertion is correct STATEMENT and reason is wrong statement. Assertion is wrong statement and reason is correct statement. Solution :Assertion and reason both are correct statements and reason explains the assertion.

Discussion

48.	Assertion (A) : p-Anisidine is a weaker base as compared to Aniline. Reason (R) : Benzene ring in Aniline exerts -R effect.
Answer» Both A and R are TRUE and R is the CORRECT EXPLANATION of A. Both A and R are true but R is not a correct explanation of A. A is true but R is FALSE. A is false but R is false. Answer :D

Discussion

49.	Assertion (A) : Ozone is prepared from oxygen in a silent electrical dicharge. Reason (R) : Formation of ozone from oxygen is an endothermic process.
Answer» Both ASSERTION (A) and REASON (R) are correct STATEMENTS, and Reason (R) is the correct EXPLANATION of the Assertion (A) Both Assertion (A) and Renson (R) are correct statements, but Reason (R) is not the correct explanation of the Assertion (A) Assertion (A) is correct, but Reason (R) is incorrect statement. Assertion (A) is incorrect, but Reason (R) is correct statement. Answer :A

Discussion

50.	Assertion (A): Oxidation of ketones is easier than aldehydes. Reason ( R) : C-C bond of ketomes is stronger than C-H bond of aldehydes.
Answer» Both ASSERTION (A) and REASON (R ) are correct statements, and Reason ( R) is the correct EXPLANATION of the Assertion (A) Both Assertion (A ) and Reason ( R) are correct statements, but Reason ( R) is not the correct explanation of the Assertion (A) Assertion (A) is correct, but Reason (R ) is incorrect statement Assertion (A) is incorrect, but Reason (R ) is correct statement. Answer :D

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Assertion (A) : Receptors are crucial to body's communication process. Reason (R) : Receptors are proteins.

Assertion (A) : Receptor proteins show selectivity for one chemical messenger over the other. Reason (R) : Chemical messenger binds to the receptor site and inhibits its natural function.

Assertion (A) : Reactivity of ketones is more than aldehydes. Reason ( R ) : The carbonyl carbon of ketones is less electrophilic as compared to aldehydes.

Assertion (A) : Reactions taking place in one step are called elementary reactions. Reason (R ) : When a sequence of elementary reactions gives us the products, the reactions are called complex reactions.

Assertion (A): Reaction between (Me_(3)CONa) (sodium ter-butoxide) and ethyliode (C_(2)H_(5)I) does not produce an ether.Reason (R): Sodium ter-butoxide is a very strongbase but is not a nucleophile.

Assertion (A) Rayon is a semisynthetic polymer and is taken as a better choice than cotton fabric. Reason (R ) Mechanical and aesthetic properties of cellulose can be improved by Acetylation

Assertion (A) : Rayon is a semisynthetic polymer and is taken as a better choice than cotton fabric. Reason (R) : Mechanical and aesthetic properties of cellulose can be improved by acetylation.

Assertion : A rate of hydrolysis of methyl chloride to methanol is higher in DMF than in water. Reason : Hydrolysis of methyl chloride follows second order kinetics.

Assertion (A) : Rate of reaction normally increases by a factor of 2 to 3 for every 10^(@) rise in temperature. Reason (R ) : Increase of temperature increasesthe number of collisions .

Assertion (A): Quaternary structure of proteins represents overall folding of polypeptide chains. Reason (R) : DNA contains four bases, adenine, guanine, cytosine and thymine.

Assertion (A) : [Pt(en)_(2)Cl_(2)]^(2+) complex is less stable than [Pt(NH_(3))_(4)Cl_(2)]^(2+) complex. Reason ( R ) : [Pt(en)_(2)Cl_(2)]^(2+) complex shows chelate effect.

Assertion (A) : Protons are better projectilesthan neutrons. Reason (R) : The neutrons being neutral do not experience repulsion from positively charged nucleus.

Assertion (A) : Propene (CH_(3)CH = CH_(2)) undergoes allylic substitution. Reason (R) : CH_(2) = CHCH_(2) (allylic) free radical is stabilised by resonance.

Assertion (A) : Primary amines with three or more carbon atoms are liquids. Reason (R) : The intermolecular association is more in primary amines than in secondary amines.

Assertion (A) : Pressure cooker reduces time for cooking.Reason (R ) : In pressure cooker boiling point get increased.

Assertion (A) : Preservative are added to food items. Reason (R) : Preservatives inhibit the growth of microorganisms.

Assertion (A) : Presence of a nitro group at ortho or para position increases the reactivity of haloarenes towards nucleophilic substitution.Reason (R ) : Nitro group, being an electron withdrawing group decreases the electron density over the benzene ring.

Assertion (A): Preparation of flourine came across number of difficulties Reason: R: It attacks all materials which are used in the preparation (glass, carbon, H_(2)O, metals)

Assertion (A) : Precipitation of silver chloride by mixing of silver nitrate and sodium chloride solutions is an instantaneous reaction. Reason (R ) : Hydrolysis of starch to give glucose occurs with the very slow speed.

Assertion (A) : Potassium permanganate forms dark purple crystals which are isostructural with those of KClO_(3). Reason (R) : MnO_(4)^(-) ions and ClO_(4)^(-) ions possess tetrahedral structures.

Assertion (A) : Potassium ferro thiocyanate answers the presences of Fe^(3+), K^(+) and SCN^(-) ions. Reason (R ) : The complex ion in coordination compound does not loose its identify and never dissociate to give simple ions.

Assertion (A) : Polytetrafluoroethene is used in making non-stick cookwares. Reason (R) : Fluorine has highest electro- negativity.

Assertion : A positive catalyst increases the rate of reaction. Reason : A positive catalyst alters reaction mechanism and decreases activation energy.

Assertion (A): Polymers like Buna-S, Buna-N and Neoprene are elastomeric polymers. Reason (R) In polymers like Buna-S and Buna-N, the polymer chains are held togetherby weakest intermolecular forces which allow the polymer to be stretched.

Assertion (A): Polyamides and polyesters are used as fibres. Reason (R) : Bakelite and urea-formaldehyde are thermoplastic polymers.

Assertion (A) : Polyester and nylon are examples of linear polymers . Reason (R) : Styron is obtained by polymerisation of styrene in thepresenceof benzoyl perodxide.

Assertion (A) : Polyamides are best used as fibres because of high tensile strength. Reason (R) : Strong intermolecular forces (like hydrogen bonding within polyamides) lead to close packing of chains and increase the crystalline character, hence, provide high tensile strength to polymers.

Assertion (A): Platinised asbestos is a better adsorbent than platinum block. Reason (R): Higher the surface area, higher is the amount adsorbed. In platinum coated asbestos the surface area is more and so it act as a better adsorbent.

Assertion (A): Physical adsorption occurs at low temperature. Reason (R) : In physical adsorption, weak Van der Waals force of attraction exist. Other weak forces exist in physical adsorption are dipole-dipole interaction and dispersion forces. As these forces are weak, heat of adsorption is low.

Assertion (A) : Phosphorus chlorides (tri and penta) are preferred over thionyl chloride for the preparation of alkyl chlorides from alcohols. Reason (R) : Phosphorus chlorides give pure alkyl hakides.

Assertion (A) : Phosphorus chlorides (tri and penta) are preferred over thionyl chloride for the preparation of alkyl chlorides from alcohols. Reason (R ) : Phosphorus chlorides give pure alkyl halides.

Assertion (A) : Phenols are stronger acids than alcohols. Reason (R ) : Phenol exhibits resonance in which the phenoxide ion gets stabilised.

Assertion (A): Phenol on nitration with Conc. HNO_(3) and H_(2)SO_(4) give a mixture of o and p-nitro phenol. Reason (R): -OH group is deactivating group.

Assertion (A) : Phenol on oxidation with Na_(2)Cr_(2)O_(7) and H_(2)SO_(4) gives benzoquinone. Reason (R) : Intramolecular hydrogen bonding occurs in o-nitrophenol.

Assertion: Phenol is more acidic than ethanol Reason: Phenoxide ion is resonance stablized

Assertion (A): Phenol give o- and p-nitrophenol on nitration with conc. HNO_(3) and H_(2)SO_(4) mixture. Reason (R) : -OH group in phenol is o- and p-directing.

Assertion (A) : Phenol forms 2,4,6-tri bromophenol on treatment with Br_(2) in carbon disulphide at 273 K. Reason (R) : Bromine polarizes carbon disulphide

Assertion (A) : Ph overset (o+) (N_2) Br^(Θ) is more acidic thanNH_4 Br. Reason (R ) : Ph overset (o+)(N)H_(3) (anilinum ion ) is resonance stabilinsed .

Assertion (A): PhBr is less reactive thanC_(2)H_(5)Br towards SN reactions. Reason (R):The forces of attrafction between RX and H_(2)O molecules are weaker than thosepresent betweenthe molecules of RX and water molelcules separate,u.

Assertion (A) : Permanent gases like H,,N, and 0, cannot be adsorbed readily. Reason (R) : Permanent gases having low critical temperature and adsorbed slowly.

Assertion (A) Penicillin (G) is an antihistamine. Reason (R) Penicillin (G) is effective against gram positive as well as gram negative bacteria.

Assertion (A) : Penicillin (G) is an antihistamine. Reason (R) : Penicillin (G) is effective against gram positive as well as gram negative bacteria.

Assertion (A) : Pauling was the first to formulate his ideas about the structure of coordination compounds. Reason (R) : In coordination compounds, metals show two types of linkages, primary and secondary.

Assertion (A) : Packing efficiency of hcp and ccp structures is 74%. Reason (R) : If the number of close packed spheres is N, then number of tetrahedral voids is N.

Assertion (A) : p-nitrophenol is more acidic than phenol Reason (R) : Nitro group helps in the stabilisation of the phenoxide ion by dispersal of negative charge due to resonance.

Assertion (A) : p-Anisidine is a weaker base as compared to Aniline. Reason (R) : Benzene ring in Aniline exerts -R effect.

Assertion (A) : Ozone is prepared from oxygen in a silent electrical dicharge. Reason (R) : Formation of ozone from oxygen is an endothermic process.

Assertion (A): Oxidation of ketones is easier than aldehydes. Reason ( R) : C-C bond of ketomes is stronger than C-H bond of aldehydes.