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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 17801. |
What are the monomers of novolac and bakelite? Whatis the differencebetween the two ? Whatare theiruses ? |
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Answer» Solution :Monomers for both the polymers are phenoland FORMALDEHYDE. Navolic: Thereactionstarts with the initial FORMATION of `o^(-)` and / or p- hydroxymethylphenol derviative whichfurther REACT to from compoundshavingringsjoined togetherthrough -`- CH_(2)` group.  Uses : Novolaci is used in PAINTS . Novolac on heating withformaldehydeundergoescross linkingto from an infusiblesolid mass called bakelite .  Uses : Bakeliteis usedfor makingcombs , phonograph records , electrical switches and handlesof variousuntensils . |
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| 17802. |
The solubility of a gas increases in a liquid solvent with |
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Answer» INCREASE in TEMPERATURE |
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| 17803. |
Which one of the following is incorrect about dimethyl ether ? |
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Answer» It has boiling POINT lower than alcohol |
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| 17804. |
Which one of the following geometry is possesed by permanganate ion? |
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Answer» Pyramidal |
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| 17805. |
Which of the following is correct about Tetraamminedithiocyanato-s cobalt(III) tris(oxalato)cobaltate(III)? |
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Answer» Formula of the COMPLEX is `[CO(SCN)_(2)(NH_(3))_(4)][Co(o x)_(3)]` Linkage isomerism is DUE to presence of `SCN^(-)` optical isomerism is exhibited due to presence of `[Co(o x)_(3)]^(3-)` complex ion, which has asymmetric structure. Geometrical isomerism is exhibited due to cationic part: 
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| 17806. |
When ethyl iodide and n-propyl iodide are allowed to react with sodium metal in ether, the number of alkanes that could be produced is |
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Answer» only one `2C_(2)H_(5)I+2Na rarr C_(2)H_(5)C_(2)H_(5)` (Butane) `2CH_(3)CH_(2)CH_(2)I rarr UNDERSET(("Hexane"))(CH_(3)CH_(2)CH_(2)CH_(2)CH_(2)CH_(3))` |
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| 17807. |
Which of the following is/are beta-lactam antibiotic/s. |
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Answer» Penicillin |
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| 17808. |
Which compound gives yellow ppt.with iodine and alkali ? |
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Answer» 2-hydroxy PROPANE |
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| 17809. |
The wavelength of the electron emitted by a metal sheet of work function 5eV when photons from EMR of wavelength 62 nm strike the metal plate |
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Answer» 82.667 Å |
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| 17810. |
Which polymer is obtained with help of Ziegler Natta catalyst ? |
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Answer» Polystryrene |
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| 17811. |
Which among the following plots are linear (a -x) is the concentration of reactant remaining after time , t (a) (a - x) vs t , for a first orderreaction (b) (a - x) vs t , for a zeroorderreaction (c) (a - x) vs t , for a secondorderreaction (d) 1/(a - x) vs t , for a secondorderreaction |
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Answer» 1 and 2 |
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| 17812. |
What is zero order reaction? Give one example. |
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Answer» SOLUTION :In the zero order reaction rate is INDEPENENT of the reactants. `H_2(g)Cl_2(g)UNDERSET((light))overset(hv)rarr2HCl(g)`. |
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| 17813. |
The standard H electrode is written as |
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Answer» `PT |H_(2)| H^(+) (a = 1)` |
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| 17814. |
What are the applications of electrochemicalseries or e.m.f. series in (1) Determining relative strength of oxidisingagent in terms of E^(@) values. |
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Answer» Solution :The applications of electrochemical series (or ELECTROMOTIVE series) are as follows : (1) Relative strength of oxidising agents in TERMS of `E_("red")^(@)` values : The `E_("call")^(@)`value is a MEASURE of the tendencyif the SPECIES to be reduced i.e., accept electrons and act as oxidising AGENT. The species mentioned on left hand side of the half reactions are oxidising agents. The substances in the upparpositions in the seriesand hence in the upper left side of the halfreactionshave large positive `E_("red")^(@)` values hence are stronger oxidisingagents. For example, `F_(2), Ce^(4+),Au^(3+)`, etc. As we move down the series, the oxidisingpower decreases . Hence from the position of the elements in the electrochemical series, oxidising agents can be selected. |
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| 17815. |
When a rod of metal A is dipped in an aqueous solution of metal B (concentration of B^(2+) = 1M) at 25^(@)C , the electrode potentials are A^(2+) /A = -0.76 Volts, B = +0.343 Volts. |
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Answer» A will gradually dissolve |
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| 17817. |
Which of the following will be correct graph for variation of boiling point with composition ? |
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Answer»
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| 17818. |
Two monomers used in the preparation of of dextron are |
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Answer» 3-hydroxy butanoic acid and 3 -hydroxy pentanoic acid |
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| 17819. |
Thermoplastics are: |
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Answer» LINEAR polymers |
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| 17820. |
._(Z)^(M)A(g)to ._(Z-4)^(M-8)B(g)+(alpha-"particles") (alpha.particles are helium nuclei, so will form He gas by trapping electrons). The radioactive disintergration follows 1st order kinetics, starting with 1 mole of A in a 16.4 litre closed flask at 127^(@)C. pressure (atm) developed after two half lives is : (R = 0.082 "litre atm"//"mol-K") |
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Answer» |
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| 17822. |
Which of the following is a free radical substitution reaction? |
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Answer»
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| 17823. |
The standard Gibbs free energy change (DeltaG^(@)) at 25^(@)C for the dissociation of N_(2)O_(4(g)) to NO_(2(g)) is (given, equilibrium cont. =0.15,R=8.314JK^(-1)mol^(-1)) |
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Answer» 1.1 kJ `=-2.303xx8.314xxlog0.15=4.7kJ` |
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| 17824. |
Give an example of thermoplastic polymer. |
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Answer» terylene |
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| 17825. |
Which of the following carbocations is expected to be most stable |
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Answer»
 (LESS STABLE due to more `e^(-)` WITHDRAWING effect of `-NO_(2)`)  (More stable due to less `e^(-)` withdrawing effect of `-NO_(2)`) |
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| 17826. |
Which of the following electronic configura Which of the following electronic configuration belong to transition elements |
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Answer» `KL, 3s^(2)p^(6)d^(5), 4S^(1)` |
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| 17827. |
What is kg-mole ? Find out the total number of electrons in a kg-mole of O_(2). |
| Answer» Solution :One kg-MOLE (or simply called one kilomole, i.e., kmol) is the MOLECULAR mass of the substance expressed in kilograms. In CGS system, one gram mole of a substance contains Avogadro's number of particles `(6.022xx10^(23))`. In MKS system, one kg-mole of a substance contains Avogadro's number of particles but its value is `6.022xx10^(25)`. THUS, 1 kg-mole of `O_(2)` will contain `6.022xx10^(26)` molecules and hence `16xx6.022xx10^(26)` ELECTRONS (as one molecules of `O_(2)` contains 16 electrons). | |
| 17828. |
Which kind of solids have a smooth surface after cleavage? |
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Answer» Crystalline |
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| 17829. |
There is ppt. of solute AB if itsproduct isgreaterthan K_(sp) value i.e. [A][B] gt K_(sp) |
Answer»  AB is precipitate if `[A^(Theta)][B^(Theta)] gt K_(sp)` AgCI is precipitate if `[Ag^(Theta)][CI^(Theta)] gt K_(sp)` `PbI_(2)`is precipitate if `[Pb^(2+)][I^(Theta)]^(2) gt K_(sp)` HENCE true. |
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| 17830. |
What is the nature of carbon atom marked with asterisk (*) sign in the following compounds? (a) CH_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)(C )-CH_(3) (b) H-underset(CH_(3))underset(|)overset(CH_(3))overset(|)(C )-CH_(2)CH_(3) ( c) CH_(3)-CH_(2)-CH_(2)-CH_(3) (d) CH_(3)-CH_(2)-CH_(2)-CH_(3) |
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Answer» |
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| 17831. |
When phenol is reacted with CHCl_(3) and NaOH followed by acidifiaction, salicylaldehyde is obtained. Which of the following species is/are involved in the above mentioned reaction as intermediate (s) ? |
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Answer»
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| 17832. |
When CH_3 CH_2 CH_2 CO ONa is heated with sodalime (NaOH + CaO), the hydrocarbon formed is |
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Answer» Butan |
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| 17833. |
Which among the following is incorrect with respect to starch? |
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Answer» Starch is a POLYMER of glucose molecules |
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| 17834. |
Which of the following convert into 1^(@) alcohol on reaction with Grignard reagent ? |
| Answer» Solution :Methanal | |
| 17835. |
Which of the following is not a conductor of electricity ? |
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Answer» SOLID NACL |
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| 17836. |
When AgNO_(3) is added to a solution of Co(NH_(3))_(5)Cl_(3), the precipitate of AgCl shows two ionizable chloride ions. This means : |
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Answer» Two chlorine atoms satisfy primary valency and one SECONDARY valency `[Co(NH_(3))_(5)Cl]Cl_(2) (aq) hArr [Co(NH_(3))_(5)Cl]^(2+) (aq) + 2Cl^(-) (aq)` |
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| 17837. |
Which product is formed when propan-1-ol is oxidised by pyridinium chlorochromate (PCC)? |
| Answer» Solution :Propanal | |
| 17838. |
The unit cell with the given structure represents _______ crystal system.(##NCERT_OBJ_FING_CHE_XII_PP_E01_001_Q01.png" width="80%"> |
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Answer» CUBIC |
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| 17839. |
The ultimate products of oxidation of most of the hydrogen and carbon in food -stuffs are |
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Answer» WATER only |
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| 17840. |
Which of the following is / are polar aprotic solvents |
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Answer» `CH_3COCH_3`(acetone) |
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| 17841. |
Which of the following complex species do not involve d_2sp^3hybridisation: |
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Answer» `[CoF_6]^(3-)` |
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| 17842. |
What are essential and non-essential amino acids ? Give two examples of each type ? |
| Answer» Solution :Out of the 20 amino acids required for protein SYNTHESIS, human body can synthesize only 10. These 10 amino acids which, the body can synthesize are called non-essential amino acids e.g. valine and phenylalanine while the REMAINING ten which the human body cannot synthesize are called essential amino acids. These essential amino acids are required for the growth of the body and they must be supplied from OUTSIDE in the human diet, e.g. GLYCINE and cysteine. | |
| 17843. |
Write the differences between physisorption and chemisorption with respect to the following: (i) Specificity (ii) Temperature dependence (iii) Reversibility, and (iv) Enthalpy change. |
Answer» SOLUTION :Difference between PHYSISORPTION and chemisorption is given in the tabular FORM as under:
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| 17844. |
Which one of the following is not a buffer solution? |
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Answer» `0.8M H_2S+0.8 M KHS` |
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| 17845. |
The standard reduction potential ofCu^(2+) // Cu and Cu^(+) // Cuare 0.337 and 0.153 V respectively . The standard electrode poetential of Cu^(2+) // Cu^(+) half cell will be |
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Answer» `0.184 V ` (3) `Cu^(+2) + 1e^(-) to Cu^(+) , (1 xx E_3^(0)) ` ,(3) = (1)-(2) ` 1 xx E_(3)^(0) = (2 xx 0.337) -(1 xx 0.153) , E_3^(0) = 0.674 - 0.153 = 0.521` |
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| 17846. |
When 16.8g of whitesolid X was heated, 4.4 g ofacid gas A thatturnedlime watermilkywas driven offtogather with 1.8 g of a gas B whichcondensed to acolourless liquid The solid that remained Ydissolved in waterto givean alklinesolution , which with excess bariumchloride solutiongave a whiteprecipitate Z .THe precipitateeffecverscedwithh acidgivingcarbondioxide identify A,B and Y and writetheequationfor thedecomposition of X |
Answer» Solution :`X: NaHCO_(3) ,Y : Na_(2)CO_(3) ,A: CO_(2) , B: H_(2)O` `rArr` X must be bicarbonate Let `MHCO_(3)` be the bicarbonate `underset(16.8)(2MHCO_(3)) overset(DELTA)(to) underset(4.4g -0.1 MOL -0.1mol)(CO_(2))` + `underset(1.8 g)(H_(2)O)` + `M_(2)CO_(3)` `rArr` Mole of `MHCO_(3) = 0.2` `rArr 0.2 = (16.8)/(M_(0)) ,M_(0) = 84` `MHCO_(2) rArr M + 60 + 1= 84` Atomic mass of `M = M = 23` `rArr M is Na rArr X "is" NaHCO_(3)` |
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| 17847. |
Which of the following is the energy of a possible excited state of hydrogen? |
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Answer» `+13.6eV` |
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| 17848. |
Which form of carbon has a two-dimensional sheet-like structure ? |
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Answer» Coal |
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| 17849. |
Which of the following is an alkoxide : |
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Answer» `CH_2=CH_2` |
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| 17850. |
Which gives a neutral solution in water? |
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Answer» `(NH_4)_2SO_4` |
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