100525 + Interview Questions in GENERAL QA IN GENERAL AWARENESS Page 576 InterviewSolution

28751.	What are the important ores of copper? How is copper extracted from copper pyrites?
Answer» Main Ores of copper is: (i) Copper pyrites (CuFeS₂), (ii) cuprite (Cu₂S) Extraction of copper: Copper is extracted to.the copper pyrite is CuFeS₂. At first free sulphur is oxidies after roasting in laboratory furnance in presence of air S + O₂ → SO₂ 4AS + 3O₂ → 2AS₂O₃ 2CuFeS₂ + O₂ → Cu₂S + 2FeS + SO₂ Smelting in blast furnance in presence of air: 2FeS + 3O₂ → 2FeO + 2SO₂ FeO + SiO₂ → FeSiO₃(Slag) Bessemerisation in bessemer converter in presence of air 2FeS + 3O₂ → 2FeO + 2SO₂ FeO + SiO₂ → FeSiO₃ 2Cu₂S + 3O₂ → 2Cu₂O + 2SO₂ 2Cu₂O + Cu₂S → 6Cu + SO₂ We get blister copper (98% + impurities) Electrolytic refining: Anode → impure copper plates cathode → Pure copper plates Electrolyte → CuSO + Solution + H₂SO₄ Pure copper deposited at cathode.

28751.

What are the important ores of copper? How is copper extracted from copper pyrites?

Answer»

Main Ores of copper is: (i) Copper pyrites (CuFeS₂), (ii) cuprite (Cu₂S)

Extraction of copper: Copper is extracted to.the copper pyrite is CuFeS₂.

At first free sulphur is oxidies after roasting in laboratory furnance in presence of air

S + O₂ → SO₂

4AS + 3O₂ → 2AS₂O₃

2CuFeS₂ + O₂ → Cu₂S + 2FeS + SO₂

Smelting in blast furnance in presence of air:

2FeS + 3O₂ → 2FeO + 2SO₂

FeO + SiO₂ → FeSiO₃(Slag)

Bessemerisation in bessemer converter in presence of air

2FeS + 3O₂ → 2FeO + 2SO₂

FeO + SiO₂ → FeSiO₃

2Cu₂S + 3O₂ → 2Cu₂O + 2SO₂

2Cu₂O + Cu₂S → 6Cu + SO₂

We get blister copper (98% + impurities)

Electrolytic refining:

Anode → impure copper plates

cathode → Pure copper plates Electrolyte → CuSO + Solution + H₂SO₄

Pure copper deposited at cathode.

Discussion

28752.	What happens when:-(i) Chlorine gas reacts with NaOH solution.(ii) Nitric acid reacts with Zn or Cu in different concentrations.
Answer» (i) 2NaOH + Cl₂ → NaCl + NaClO + H₂O (ii) HNO₃ reacts with Zn we get 2HNO₃ + Zn = Zn(NO₃) + NO₂ + H₂O HNO₃ react with Cu, we get 3Cu + 8HNO₃ → 3Cu(NO₃)₂ + 2NO + 4H₂O

28752.

What happens when:-(i) Chlorine gas reacts with NaOH solution.(ii) Nitric acid reacts with Zn or Cu in different concentrations.

Answer»

(i) 2NaOH + Cl₂ → NaCl + NaClO + H₂O

(ii) HNO₃ reacts with Zn we get

2HNO₃ + Zn = Zn(NO₃) + NO₂ + H₂O

HNO₃ react with Cu, we get

3Cu + 8HNO₃ → 3Cu(NO₃)₂ + 2NO + 4H₂O

Discussion

28753.	Which of the following oxidies shows electrical properties like metals?(a) SiO2(b) MgO(c) SO2(S)(d) CrO2
Answer» Answer is (a) SiO₂

Discussion

28754.	Which of the following is an amorphous solid?(a) Graphite (C)(b) Quartz Glass (SiO2)(c) Chromite Alum(d) Silicon Carbide (SiC)
Answer» Answer is (d) Silicon Carbide (SiC)

Discussion

28755.	Which of the following aqueous solution should have the highest boiling point?(a) 1.0 M NaOH(b) 1.0 M Na2SO4(c) 1.0 M NH4NO3(d) 1.0 M KNO3
Answer» Answer is (a) 1.0 M NaOH

Discussion

28756.	Calculate `(a) DeltaG^(Theta)` and (b) the equilibrium constant for the formation of `NO_(2)` from NO and `O_(2)` at 298 K `NO(g) +1//2 O_(2) (g) hArr NO_(2)(g)` where `Delta_(f) G^(Theta) (NO_(2)) =52 .0 kJ//mol, Delta_(f) G^(Theta) (NO) =87.0 kJ//mol, Delta_(f) G^(Theta) (O_(2)) =0kJ//mol.`
Answer» `Delta_(r)G^(Θ)=SigmaDelta_(f)G^(Θ)("Products")-SigmaDelta_(f)G^(Θ)("Reactants")` `Delta_(f)G^(Θ)(NO_(2))-[SigmaDelta_(f)G^(Θ)(NO)+1/2Delta_(f)G^(@)(O_(2))]` `=52.0-(87.0+1/2xx0)=-35.0 kJ mol^(-1)` b. `-DeltaG^(Θ)=2.303RT log K. "Hence", -(-35000)` `=2.303xx8.314xx298xxlog K` or `log K=6.1341 or K=1.361xx10^(6)`

Discussion

28757.	Carbon reduction process is used for the extraction ofA. `Hg`B. `Zn`C. `Cr`D. `Fe`
Answer» Correct Answer - D `Fe_(2)O_(3) + 3Crarr 3CO +2Fe`

Discussion

28758.	If the quantum number for 5th electron of carbon are 2, 1, 0 and `1/2`.Then what is the correct set for its 6th electron ?A. `2,0,+1,+1/2`B. `2,1,0,+1/2`C. `2,1,+1,+1/2`D. `2,1,-1,-1/2`
Answer» Correct Answer - D `CH_3-undersetOunderset"\|\|"C-H underset((ii)H^(o+)) overset((i)NaOH + HCN) to (A) underset"Hydrolysis" overset"Partial"to (B)`

Discussion

28759.	Which of the following is Tribasic?(a) H3PO2(b) H3PO3(c) H4P2O7(d) H3PO4
Answer» Answer is (b) H₃PO₃

Discussion

28760.	Sulphide ores are generally concentrated by:(a) Froth floatation method(b) Roasting(c) Gravity(d) Reducton by Carbon
Answer» Answer is (b) Roasting

Discussion

28761.	Annealing of stell is the precess of heating steelA. to a bright red hot and then cooling it slowelyB. to a bright red hot and then cooling it suddenlyC. to a temperature much below redness and cooling it slowlyD. none of these
Answer» Correct Answer - A Heating and holding at certain temperature.

Discussion

28762.	The important step in the extraction of metal from carbonate ore isA. CalcinationB. RoastingC. Electro-reductionD. Cupellation
Answer» Correct Answer - A Calcination `ZnCO_(3)rarrZnO+Co_(2)`

Discussion

28763.	Which one of the following sulphide ores is concentrated by chemical leaching ?A. PyriteB. GalenaC. EpsomiteD. argentite
Answer» Correct Answer - D Ore of aluminium are concetrated by leaching

Discussion

28764.	Amoxycillin isA. Broad spectrum antibioticB. BacteruistaticC. Synthetic modification of penicillinD. (a) & (c ) both
Answer» Correct Answer - D Fact

Discussion

28765.	An aeroplane is flying at a height of 14 km where temperature is – 45°C. The speed of the plane is corresponding to M = 2. Find the speed of the plane if R = 287 J/kg K and γ = 1.4.
Answer» Temperature (at a height of 14 km), t = – 45°C. T = – 45 + 273 = 228 K Mach number, M = 2 Gas constant, R = 287 J/kg K γ = 1.4 Speed of the plane, V : Sonic velocity, (C) is given by, C = \(\sqrt{γRT}\) (assuming the process to be adiabatic) = \(\sqrt{1.4\times287\times228}\) = 302.67 m/s M = \(\cfrac VC\) 2 = \(\cfrac V{302.67}\) V = 2 × 302.67 = 605.34 m/s = \(\cfrac{605.34\times3600}{1000}\) = 2179.2 km/h

28765.

An aeroplane is flying at a height of 14 km where temperature is – 45°C. The speed of the plane is corresponding to M = 2. Find the speed of the plane if R = 287 J/kg K and γ = 1.4.

Answer»

Temperature (at a height of 14 km), t = – 45°C.

T = – 45 + 273 = 228 K Mach number, M = 2

Gas constant, R = 287 J/kg K γ = 1.4

Speed of the plane, V :

Sonic velocity, (C) is given by,

C = \(\sqrt{γRT}\) (assuming the process to be adiabatic)

= \(\sqrt{1.4\times287\times228}\) = 302.67 m/s

M = \(\cfrac VC\)

2 = \(\cfrac V{302.67}\)

V = 2 × 302.67 = 605.34 m/s = \(\cfrac{605.34\times3600}{1000}\) = 2179.2 km/h

Discussion

28766.	When the first electron gain enthalpy (ΔegH) of oxygen is –141kJ/mol, its gain enthalpy is: (1) almost the same as that of the first (2) negative, but less negative than the first (3) a positive value (4) a more negative value than the first
Answer» The correct option (3) a positive value Explanation: Second electron gain enthalpy is always positive.

28766.

When the first electron gain enthalpy (ΔegH) of oxygen is –141kJ/mol, its gain enthalpy is: (1) almost the same as that of the first (2) negative, but less negative than the first (3) a positive value (4) a more negative value than the first

Answer»

The correct option

(3) a positive value

Explanation:

Second electron gain enthalpy is always positive.

Discussion

28767.	What criterion is followed for the selectrion of the stationary phase in chromatography?
Answer» The stationary plase is selected in such a way that the impurities are more strongly adsorbed on the stationary phase than element to be purified. Under these conditions, when the clumn is extracted, the impurities will be raetained by the stationary phase while the pure component is easily eluted.

Discussion

28768.	The ions from among the following which are colourless are `:` `(i)Ti^(+4)" "(ii)Cu^(+1)" "(iii)Co^(+3)" "(iv)Fe^(+2)`A. (i) and (ii) onlyB. (i),(ii) and (iii)C. (iii) and (iv)D. (ii) and (iii)
Answer» Correct Answer - A (i)Valance shell electron configuration of `Ti^(4+)` is `3d^@ 4s^@`.As there is no unpaired electrons for d-d transition. The solution of ions will be colourless. (ii)Valance shell electron configuration of `Cu^(+)` is `3d^10 4s^@`.As electrons are paired, there is no d-d transition, so the solution of ions will be colourless. (iii)Valance shell electron configuration of `Co^(3+)` is `3d^6 4s^@`.As there are 4 unpaired electrons for d-d transition of electron, so The solution of ions will be coloured. (iv)Valance shell electron configuration of `Fe^(2+)` is `3d^6 4s^@`.As there are 4 unpaired electrons there is d-d transition. The solution of ions will be coloured.

Discussion

28769.	What is meant by the term "chromatography"?
Answer» The term chromatography was originally derived from the greek word chroma meaning colour and graphy meaning writing because the method was first used for the separation of coloured substances (plant pigments) into individual components. Now the term chromatography has lost its original meaning and the method is widely used for separation, purification, identification and characterisation of the components of a mixture whether coloured or colourless.

Discussion

28770.	Ferric sulphate on heating gives:A. Both `SO_2` and `SO_3`B. `SO_2` onlyC. `SO_3` onlyD. `Fe_2(SO_4)_3` only
Answer» Correct Answer - A `FeSO_4 oversetDelta to Fe_2O_3+SO_2+SO_3`

Discussion

28771.	Anhydrous ferric chloride is prepared byA. Heating hydrated ferric chloride at a high temperature in a stream of air.B. Heating metallic iron in a stream of dry chlorine gas.C. Reaction of ferric oxide with HCI (aq).D. Reaction of metallic iron with HCI (aq).
Answer» Correct Answer - B `2Fe+3Cl_2 to 2FeCl_3`(anhydrous) , (A), ( C) and (D) do not give anhydrous `FeCl_3` but hydrated `FeCl_3`.

Discussion

28772.	What criterion is followed for the selection of the stationary phase in chromatography?
Answer» The stationary phase is selected in such a way that the components of the sample have different solubility’s in the phase. Hence, different components have different rates of movement through the stationary phase and as a result, can be separated from each other.

Discussion

28773.	`2.8 xx 10^(-2) kg ` of nitrogen is expanded isothermally and reversibly at 300 k from 15.15 `xx 10^(5) Nm^(-2)` when the work done is found to be - 17. 33 kJ .Find the final pressure .
Answer» Correct Answer - Final pressure `=1456.8 Nm^(-2)` Given : Mass of nitrogen `= W= 2.8 xx 10^(-2) kg` Temperature = T = 300 K Work obtained in expansion `=W_(max)= - 17 .33 kJ =- 17330 J` Initial pressure `=P_(1) = 15. 15 xx 10^(5) Nm^(-2) = 1.515 xx 10^(6) Nm^(-2)` Molar mass of nitrogen `(N_(2)) = M_(N_(2)) = 28 xx 10^(-3) kg mol^(-1)` Final pressure `= P_(2) = ?` Number of moles of `N_(2) = n. (W)/(M_(N_(2))) = (2.8 xx 10^(-2))/(28xx 10^(-3)) = 1 mol` `W_(max) = - 2.303 xx nRT log _(10) .(P_(1))/(P_(2))` `17330 = 2.303 xx 1 xx 8.314 xx 300 xx log _(10). (1.515 xx 10^(6))/(P_(2))` `:. (17330)/(2.303 xx 1xx 8.314 xx 300) = [ log_(10) 1.515 xx 10^(6) - log_(10) P_(2)]` `3.017 = 6 . 1804 - log _(10) P_(2)` `:. log_(10) P_(2) = 6.1804 - 3.017 =3 . 1634` `:. P_(2) = `Antilog 3.1634 `= 1456.8 Nm^(-2)`

Discussion

28774.	For the reaction 2N2O5 → 4NO2+O2, the rate of reaction is(a) \(\frac{1}{2}\frac{d}{dt}\) [N2O5](b) 2\(\frac{d}{dt}\) [N2O5](c) \(\frac{1}{4}\frac{d}{dt}\) [NO2](d) 4 \(\frac{d}{dt}\) [NO2]
Answer» (c) \(\frac{1}{4}\frac{d}{dt}\) [NO₂]

Discussion

28775.	The Substitution reaction of alkyl halide mainly occurs by SN1 & SN2 mechanism. Whatever mechanism alkyl halide follow for the substitution reaction to occur, the polarity of the carbon halogen bond is responsible for these substitution reactions. The rate of SN1 reactions are governed by the stability of carbocation whereas the rate of SN2 reactions is decided by steric factors if the starting material is a chiral compound we may end up with an inverted product or racemic mixture depending upon the type of reaction mixture followed by the alkyl halide.i. Racemisation occurs in a). SN1 reaction b). SN2 reactionc). both SN1 & SN2 reactions d). neither SN1 nor SN2 reactionsii. If an optically active alkyl halide undergoes substitution reaction by SN1 mechanism, which one not happens:a). Formation of racemic mixture b). Formation of inverted product c). formation of carbocation d). formation of transition stateiii. The SN1 reaction of optically active alkyl halides lead to a). retention of configuration b). racemisation c). inversion of configuration d). none of aboveiv. For which of the following undergoes nucleophilic substitution exclusively by SN1 mechanism a). ethyl chloride b). Isopropyl chloride c). chlorobenzene d). benzyl chloridev. ASSERTION- When a solution is separated from the pure solvent by a semipermeable membrane, the solvent molecules pass through it from pure solvent side to the solution side. REASON- Diffusion of solvent occurs from a region of high concentration solution to a region of low concentration solution. a. Both assertion and reason are true, and reason is the correct explanation of assertion. b. Both assertion and reason are true, but reason is not the correct explanation of assertion. c. Assertion is true but reason is false. d. Both assertion and reason are false.
Answer» (i). b (ii). d (iii). b (iv). d

28775.

The Substitution reaction of alkyl halide mainly occurs by SN1 & SN2 mechanism. Whatever mechanism alkyl halide follow for the substitution reaction to occur, the polarity of the carbon halogen bond is responsible for these substitution reactions. The rate of SN1 reactions are governed by the stability of carbocation whereas the rate of SN2 reactions is decided by steric factors if the starting material is a chiral compound we may end up with an inverted product or racemic mixture depending upon the type of reaction mixture followed by the alkyl halide.i. Racemisation occurs in a). SN1 reaction b). SN2 reactionc). both SN1 & SN2 reactions d). neither SN1 nor SN2 reactionsii. If an optically active alkyl halide undergoes substitution reaction by SN1 mechanism, which one not happens:a). Formation of racemic mixture b). Formation of inverted product c). formation of carbocation d). formation of transition stateiii. The SN1 reaction of optically active alkyl halides lead to a). retention of configuration b). racemisation c). inversion of configuration d). none of aboveiv. For which of the following undergoes nucleophilic substitution exclusively by SN1 mechanism a). ethyl chloride b). Isopropyl chloride c). chlorobenzene d). benzyl chloridev. ASSERTION- When a solution is separated from the pure solvent by a semipermeable membrane, the solvent molecules pass through it from pure solvent side to the solution side. REASON- Diffusion of solvent occurs from a region of high concentration solution to a region of low concentration solution. a. Both assertion and reason are true, and reason is the correct explanation of assertion. b. Both assertion and reason are true, but reason is not the correct explanation of assertion. c. Assertion is true but reason is false. d. Both assertion and reason are false.

Answer»

(i). b

(ii). d

(iii). b

(iv). d

Discussion

28776.	Out of `KCI` and `CaO`, which has higher lattice energy and why?
Answer» `CaO` has higher lattice energy because of higher charge `(+2 or -2)` whereas in `KCl` each ion carry one unit of charge.Since, lattice energy `prop` charge on the ions

Discussion

28777.	Which has least number of atoms ?A. `1gm O`B. `1gm O_(2)`C. `1gm O_(3)`D. `1 gm F_(2)`
Answer» Correct Answer - D Which has least …………… `\|(,underset(1/16)(n_(O)=),underset(1/32)(n_(O_(2))=),underset(1/48)(n_(O_(2))=),underset(1/38)(n_(F_(2))=)),("Molecules",1/16N_(A),1/32N_(A),1/48N_(A),1/38N_(A)),("Atoms",1/16N_(A),2xx1/32N_(A),3xx1/48N_(A),2xx1/38N_(A))\|`

Discussion

28778.	Account for the following :Zinc is a comparatively a soft metal, iron and chromium are typically hard.
Answer» Iron and Chromium are having high enthalpy of atomization due to the presence of unpaired electrons, which accounts for their hardness. However, Zinc has low enthalpy of atomization as it has no unpaired electron. Hence zinc is comparatively a soft metal.

Discussion

28779.	A number of spherical conductors of different radii are given charge such that the charge density of each conductor is inversely proportional to its radius. The conductors will have (a) the same potential (b) the same potential energy (c) the same charge (d) potentials inversely proportional to their radii
Answer» Correct Answer is: (a) the same potential V = Q/C = 4πR²σ/4πε₀R = Rσ/ε₀. Here, σ ∝ 1/R or σR = constant. ∴ all the conductors are at the same potential.

28779.

A number of spherical conductors of different radii are given charge such that the charge density of each conductor is inversely proportional to its radius. The conductors will have (a) the same potential (b) the same potential energy (c) the same charge (d) potentials inversely proportional to their radii

Answer»

Correct Answer is: (a) the same potential

V = Q/C = 4πR²σ/4πε₀R = Rσ/ε₀.

Here, σ ∝ 1/R

or σR = constant.

∴ all the conductors are at the same potential.

Discussion

28780.	The correct name of the following polymer is :(1) Polytert-butylene (2) Polyisobutane (3) Polyisobutylene (4) Polyisoprene
Answer» The Correct option is (3) Polyisobutylene

28780.

The correct name of the following polymer is :(1) Polytert-butylene (2) Polyisobutane (3) Polyisobutylene (4) Polyisoprene

Answer»

The Correct option is (3) Polyisobutylene

Discussion

28781.	Which of the following is a thermosetting polymer? (1) Bakelite (2) NyIon6 (3) PVC (4) Buna-N
Answer» Correct option (1) Bakelite Explanation: Bakelite is a thermosetting polymer, thermosetting polymers are also called as 3D-polymer or cross link polymer.

28781.

Which of the following is a thermosetting polymer? (1) Bakelite (2) NyIon6 (3) PVC (4) Buna-N

Answer»

Correct option (1) Bakelite

Explanation:

Bakelite is a thermosetting polymer, thermosetting polymers are also called as 3D-polymer or cross link polymer.

Discussion

28782.	The correct match between Item-I and Item-II is : Item-IItem-II(a)High density polythene(I)Condensation at high temperature & pressure(b)Polyacrylonitrile (II)Condensation at high temperature & pressure(c)Novolac (III)Ziegler-Natta Catalyst (d)Nylon 6(IV)Acid or base catalyst (1) (a) → (IV), (b) → (II), (c) → (I), (d) → (III) (2) (a) → (III), (b) → (I), (c) → (IV), (d) → (II) (3) (a) → (II), (b) →(IV), (c) → (I), (d) → (III) (4) (a) → (III), (b) → (I), (c) → (II), (d) → (IV)
Answer» Correct option (2) (a) → (III), (b) → (I), (c) → (IV), (d) → (II) Explanation: Nylon –6 is condensation polymer of capzalocatiom at higher temp and presser. Novalac is obtained by acid or base catalyored polymerization of phenol and termaldehyde high-density plythere is obtained by using Ziegler natta catalyst. Polyacrylonitrile is obtained by acrylonitrile using peroxide or catalyst.

28782.

The correct match between Item-I and Item-II is : Item-IItem-II(a)High density polythene(I)Condensation at high temperature & pressure(b)Polyacrylonitrile (II)Condensation at high temperature & pressure(c)Novolac (III)Ziegler-Natta Catalyst (d)Nylon 6(IV)Acid or base catalyst (1) (a) → (IV), (b) → (II), (c) → (I), (d) → (III) (2) (a) → (III), (b) → (I), (c) → (IV), (d) → (II) (3) (a) → (II), (b) →(IV), (c) → (I), (d) → (III) (4) (a) → (III), (b) → (I), (c) → (II), (d) → (IV)

Answer»

Correct option (2) (a) → (III), (b) → (I), (c) → (IV), (d) → (II)

Explanation:

Nylon –6 is condensation polymer of capzalocatiom at higher temp and presser. Novalac is obtained by acid or base catalyored polymerization of phenol and termaldehyde high-density plythere is obtained by using Ziegler natta catalyst. Polyacrylonitrile is obtained by acrylonitrile using peroxide or catalyst.

Discussion

28783.	In a given polymers which is a condensation polymer.(1) Teflon(2) Neoprene(3) Buna - S(4) Nylon-6,6
Answer» The correct option (4) Nylon-6,6 Explanation: Except Nylon-6,6 all other given polymers are addition polymers.

28783.

In a given polymers which is a condensation polymer.(1) Teflon(2) Neoprene(3) Buna - S(4) Nylon-6,6

Answer»

The correct option (4) Nylon-6,6

Explanation:

Except Nylon-6,6 all other given polymers are addition polymers.

Discussion

28784.	An ideal liquid flows through the horizontal pipe AB, which is of uniform cross-section. The vertical pipes 1, 2 and 3 are equispaced. The liquid levels in these pipes are at heights h1, h2 and h3 respectively above AB. Liquid flows from A to B in AB.(a) h1 = h2 = h3(b) h2 = 1/2 (h1 + h3)(c) h2 > 1/2 (h1 + h3)(d) h2 < 1/2 (h1 + h3)
Answer» Correct Answer is;(a) h₁ = h₂ = h₃ As the tube is horizontal and the velocity of flow is the same at all points, the liquid pressure is constant.

28784.

An ideal liquid flows through the horizontal pipe AB, which is of uniform cross-section. The vertical pipes 1, 2 and 3 are equispaced. The liquid levels in these pipes are at heights h1, h2 and h3 respectively above AB. Liquid flows from A to B in AB.(a) h1 = h2 = h3(b) h2 = 1/2 (h1 + h3)(c) h2 > 1/2 (h1 + h3)(d) h2 < 1/2 (h1 + h3)

Answer»

Correct Answer is;(a) h₁ = h₂ = h₃

As the tube is horizontal and the velocity of flow is the same at all points, the liquid pressure is constant.

Discussion

28785.	Which of the following has minimum heat of hydrogenation.(i) ethene (ii) Propene (iii) cis-2-butene(iv) trans-2-butene
Answer» Correct Option- (iv) trans-2-butene Explanation- maximum stable alkene means minimum reactive.

28785.

Which of the following has minimum heat of hydrogenation.(i) ethene (ii) Propene (iii) cis-2-butene(iv) trans-2-butene

Answer»

Correct Option- (iv) trans-2-butene

Explanation-

maximum stable alkene means minimum reactive.

Discussion

28786.	If Heat of hydrogenation of 1-butene is 30 Kcal then heat of hydrogenation of 1,3-butadiene is ? (i) 30(ii)60(iii) 57(iv) 25
Answer» Correct Option- (iii) 57 Explanation- 1,3-butadiene requires two moles of hydrogen so heat of hydrogenation should be 60 Kcal but 1,3-butadiene is stabilized by resonance than propane so heat of hydrogenation of 1,3-butadiene will not be twice of 30. Actual ΔH - 60 > ΔH > 30 Kcal.

28786.

If Heat of hydrogenation of 1-butene is 30 Kcal then heat of hydrogenation of 1,3-butadiene is ? (i) 30(ii)60(iii) 57(iv) 25

Answer»

Correct Option- (iii) 57

Explanation-

1,3-butadiene requires two moles of hydrogen so heat of hydrogenation should be 60 Kcal but 1,3-butadiene is stabilized by resonance than propane so heat of hydrogenation of 1,3-butadiene will not be twice of 30.

Actual ΔH - 60 > ΔH > 30 Kcal.

Discussion

28787.	Which is order of heat of hydrogenation for the following set of molecules :-
Answer» Correct Answer - `(1) II gt I (2) III gt II gt IV gt I (3) II gt III gt I`

Discussion

28788.	Which of the following statement is incorrect for orbital of hydrogen atom ?(1) It is possible to find an electron at a distance 2 a0(a0 = Bohr radius)(2) The magnitude of potential energy is twice of kinetic energy for a given orbit(3) The total energy of an electron is maximum kinetic energy for a given orbit(4) The total energy of an electron is maximum in its first orbit.(4) The probability density of finding an electron is maximum at the nucleus
Answer» Correct option (3) The total energy of an electron is maximum kinetic energy for a given orbit Explanation: Total energy of electron is minimum in first orbit in H-atom

28788.

Which of the following statement is incorrect for orbital of hydrogen atom ?(1) It is possible to find an electron at a distance 2 a0(a0 = Bohr radius)(2) The magnitude of potential energy is twice of kinetic energy for a given orbit(3) The total energy of an electron is maximum kinetic energy for a given orbit(4) The total energy of an electron is maximum in its first orbit.(4) The probability density of finding an electron is maximum at the nucleus

Answer»

Correct option (3) The total energy of an electron is maximum kinetic energy for a given orbit

Explanation:

Total energy of electron is minimum in first orbit in H-atom

Discussion

28789.	Reactivity order of the following alkenes for hydrochlorination (HCl) is (I) `CH_(2) = CH - Cl` (II) `(CH_(3))_(2)C=CH_(2)` (III) `CH_(2) = CH - CHO`A. `I gt II gt III`B. `II gt III gt I`C. `II gt I gt III`D. `III gt I gt II`
Answer» Correct Answer - C

Discussion

28790.	Assertion:- Phenoxide is more stable than phenol. Reason:- Both are aromatic in nature.A. If both Assertion `&` Reason are True `&` the Reason is a correct explanation of the Assertion.B. If both Assertion `&` Reason are True but Reason is not a correct explanation of the Assertion.C. If Assertion is True but the Reason is False.D. If both Assertion `&` Reason are False.
Answer» Correct Answer - B

Discussion

28791.	Assertion:- Ter-utyl chloride on treatment with Na metal gives isobutane and Isobutylene. Reason:- It is known as wurtz reaction.A. If both Assertion `&` Reason are True `&` the Reason is a correct explanation of the Assertion.B. If both Assertion `&` Reason are True but Reason is not a correct explanation of the Assertion.C. If Assertion is True but the Reason is False.D. If both Assertion `&` Reason are False.
Answer» Correct Answer - C

Discussion

28792.	Which of the following is amorphous form of silica(1) Quartz(2) Kieselguhr(3) Tridymite(4) Cristobalite
Answer» Kieselguhr is amorphous form of silica

Discussion

28793.	The layer of atmosphere between 10 km to 50 km above the sea level is called as : (1) troposphere (2) thermosphere (3) stratosphere (4) mesosphere
Answer» Correct option (3) stratosphere Explanation: Memory based.

28793.

The layer of atmosphere between 10 km to 50 km above the sea level is called as : (1) troposphere (2) thermosphere (3) stratosphere (4) mesosphere

Answer»

Correct option (3) stratosphere

Explanation:

Memory based.

Discussion

28794.	The amorphous from of silica is : (1) kieselguhr (2) tridymite (3) cristobalite (4) quartz
Answer» Correct option (1) kieselguhr Explanation: Kieselguhr is amorphous form of silica.

28794.

The amorphous from of silica is : (1) kieselguhr (2) tridymite (3) cristobalite (4) quartz

Answer»

Correct option (1) kieselguhr

Explanation:

Kieselguhr is amorphous form of silica.

Discussion

28795.	Identify the compound 'X'(1) Toluidine(2) Benzamide(3) Para-Cresol(4) Oleic acid
Answer» The correct option is (3). Explanation: Both Para-Cresol and Oleic acid form salt with 10% NaOH, but Para-Cresol salt is soluble whereas Oleic acid salt is insoluble due to very long unsaturated carbon chain.

28795.

Identify the compound 'X'(1) Toluidine(2) Benzamide(3) Para-Cresol(4) Oleic acid

Answer»

The correct option is (3).

Explanation:

Both Para-Cresol and Oleic acid form salt with 10% NaOH, but Para-Cresol salt is soluble whereas Oleic acid salt is insoluble due to very long unsaturated carbon chain.

Discussion

28796.	Correct statements among a to d regarding silicones are (a) They are polymers with hydrophobic character (b) They are biocompatible (c) In general, they have high thermal stability and low dielectric strength (d) Usually, they are resistant to oxidation and used as greases (1) a, b and c only (2) a and b only (3) a, b,c and d (4) a, b and d only
Answer» Correct option (4) a, b and d only Explanation: Properties of silicones are as follows. (1) They are polymers with hydrophobic character. (2) They are biocompatible. (3) They are used as grease. (4) They are resistant to oxidation.

28796.

Correct statements among a to d regarding silicones are (a) They are polymers with hydrophobic character (b) They are biocompatible (c) In general, they have high thermal stability and low dielectric strength (d) Usually, they are resistant to oxidation and used as greases (1) a, b and c only (2) a and b only (3) a, b,c and d (4) a, b and d only

Answer»

Correct option (4) a, b and d only

Explanation:

Properties of silicones are as follows.

(1) They are polymers with hydrophobic character.

(2) They are biocompatible.

(3) They are used as grease.

(4) They are resistant to oxidation.

Discussion

28797.	Differentiate between somaclones and gametoclones. Who proposed the term somaclones?
Answer» While somaclones are plant variants obtained from tissue cultures of somatic tissues, gametoclones are plant variants with gametophytic origin obtained from tissue such as pollen or egg cell. Larkin and Scowcroft (1981) proposed the term 'somaclones'

28797.

Differentiate between somaclones and gametoclones. Who proposed the term somaclones?

Answer»

While somaclones are plant variants obtained from tissue cultures of somatic tissues, gametoclones are plant variants with gametophytic origin obtained from tissue such as pollen or egg cell.

Larkin and Scowcroft (1981) proposed the term 'somaclones'

Discussion

28798.	An organic compound neither reacts with neutral ferric chloride solution nor with Fehling solution. It however, reacts with Grignard reagent and gives positive iodoform test. The compound is -
Answer» Correct option (1) Explanation: No phenolic group No Aldehyde group

28798.

An organic compound neither reacts with neutral ferric chloride solution nor with Fehling solution. It however, reacts with Grignard reagent and gives positive iodoform test. The compound is -

Answer»

Correct option (1)

Explanation:

No phenolic group

No Aldehyde group

Discussion

28799.	Assertion : Ozone is destroyed by CFCs in the upper stratosphere. Reason : Ozone holes increase the amount of UV radiation reaching the earth. (1) Assertion is false, but the reason is correct (2) Assertion and reason are incorrect . (3) Assertion and reason are both correct, and the reason is the correct explanation for the assertion (4) Assertion and reason are correct, but the reason in not the explanation for the assertion
Answer» Correct option (4) Assertion and reason are correct, but the reason in not the explanation for the assertion Explanation: Ozonalayer is depleted due to CFCS

28799.

Assertion : Ozone is destroyed by CFCs in the upper stratosphere. Reason : Ozone holes increase the amount of UV radiation reaching the earth. (1) Assertion is false, but the reason is correct (2) Assertion and reason are incorrect . (3) Assertion and reason are both correct, and the reason is the correct explanation for the assertion (4) Assertion and reason are correct, but the reason in not the explanation for the assertion

Answer»

Correct option (4) Assertion and reason are correct, but the reason in not the explanation for the assertion

Explanation:

Ozonalayer is depleted due to CFCS

Discussion

28800.	In the following compounds, the decreasing order of basic strength will be - (1) C2H5NH2 > NH3 > (C2H5)2NH (2) NH3 > C2H5NH2 > (C2H5)2NH (3) (C2H5)2NH > NH3 > C2H5NH2 (4) (C2H5)2NH > C2H5NH2 > NH3
Answer» Correct option (4) (C₂H₅)₂NH > C₂H₅NH₂ > NH₃ Explanation: Due to +I effect

28800.

In the following compounds, the decreasing order of basic strength will be - (1) C2H5NH2 > NH3 > (C2H5)2NH (2) NH3 > C2H5NH2 > (C2H5)2NH (3) (C2H5)2NH > NH3 > C2H5NH2 (4) (C2H5)2NH > C2H5NH2 > NH3

Answer»

Correct option (4) (C₂H₅)₂NH > C₂H₅NH₂ > NH₃

Explanation:

Due to +I effect

Discussion

Explore topic-wise InterviewSolutions in .

What are the important ores of copper? How is copper extracted from copper pyrites?

What happens when:-(i) Chlorine gas reacts with NaOH solution.(ii) Nitric acid reacts with Zn or Cu in different concentrations.

Which of the following oxidies shows electrical properties like metals?(a) SiO2(b) MgO(c) SO2(S)(d) CrO2

Which of the following is an amorphous solid?(a) Graphite (C)(b) Quartz Glass (SiO2)(c) Chromite Alum(d) Silicon Carbide (SiC)

Which of the following aqueous solution should have the highest boiling point?(a) 1.0 M NaOH(b) 1.0 M Na2SO4(c) 1.0 M NH4NO3(d) 1.0 M KNO3

Calculate `(a) DeltaG^(Theta)` and (b) the equilibrium constant for the formation of `NO_(2)` from NO and `O_(2)` at 298 K `NO(g) +1//2 O_(2) (g) hArr NO_(2)(g)` where `Delta_(f) G^(Theta) (NO_(2)) =52 .0 kJ//mol, Delta_(f) G^(Theta) (NO) =87.0 kJ//mol, Delta_(f) G^(Theta) (O_(2)) =0kJ//mol.`

Carbon reduction process is used for the extraction ofA. `Hg`B. `Zn`C. `Cr`D. `Fe`

If the quantum number for 5​th electron of carbon are 2, 1, 0 and `1/2`.Then what is the correct set for its 6th electron ?A. `2,0,+1,+1/2`B. `2,1,0,+1/2`C. `2,1,+1,+1/2`D. `2,1,-1,-1/2`

Which of the following is Tribasic?(a) H3PO2(b) H3PO3(c) H4P2O7(d) H3PO4

Sulphide ores are generally concentrated by:(a) Froth floatation method(b) Roasting(c) Gravity(d) Reducton by Carbon

Annealing of stell is the precess of heating steelA. to a bright red hot and then cooling it slowelyB. to a bright red hot and then cooling it suddenlyC. to a temperature much below redness and cooling it slowlyD. none of these

The important step in the extraction of metal from carbonate ore isA. CalcinationB. RoastingC. Electro-reductionD. Cupellation

Which one of the following sulphide ores is concentrated by chemical leaching ?A. PyriteB. GalenaC. EpsomiteD. argentite

Amoxycillin isA. Broad spectrum antibioticB. BacteruistaticC. Synthetic modification of penicillinD. (a) & (c ) both

An aeroplane is flying at a height of 14 km where temperature is – 45°C. The speed of the plane is corresponding to M = 2. Find the speed of the plane if R = 287 J/kg K and γ = 1.4.

When the first electron gain enthalpy (ΔegH) of oxygen is –141kJ/mol, its gain enthalpy is: (1) almost the same as that of the first (2) negative, but less negative than the first (3) a positive value (4) a more negative value than the first

What criterion is followed for the selectrion of the stationary phase in chromatography?

The ions from among the following which are colourless are `:` `(i)Ti^(+4)" "(ii)Cu^(+1)" "(iii)Co^(+3)" "(iv)Fe^(+2)`A. (i) and (ii) onlyB. (i),(ii) and (iii)C. (iii) and (iv)D. (ii) and (iii)

What is meant by the term "chromatography"?

Ferric sulphate on heating gives:A. Both `SO_2` and `SO_3`B. `SO_2` onlyC. `SO_3` onlyD. `Fe_2(SO_4)_3` only

Anhydrous ferric chloride is prepared byA. Heating hydrated ferric chloride at a high temperature in a stream of air.B. Heating metallic iron in a stream of dry chlorine gas.C. Reaction of ferric oxide with HCI (aq).D. Reaction of metallic iron with HCI (aq).

What criterion is followed for the selection of the stationary phase in chromatography?

`2.8 xx 10^(-2) kg ` of nitrogen is expanded isothermally and reversibly at 300 k from 15.15 `xx 10^(5) Nm^(-2)` when the work done is found to be - 17. 33 kJ .Find the final pressure .

For the reaction 2N2O5 → 4NO2+O2, the rate of reaction is(a) \(\frac{1}{2}\frac{d}{dt}\) [N2O5](b) 2\(\frac{d}{dt}\) [N2O5]​(c) \(\frac{1}{4}\frac{d}{dt}\) [NO2](d) 4 \(\frac{d}{dt}\) [NO2] ​​​​​​

Out of `KCI` and `CaO`, which has higher lattice energy and why?

Which has least number of atoms ?A. `1gm O`B. `1gm O_(2)`C. `1gm O_(3)`D. `1 gm F_(2)`

Account for the following :Zinc is a comparatively a soft metal, iron and chromium are typically hard.

The correct name of the following polymer is :(1) Polytert-butylene (2) Polyisobutane (3) Polyisobutylene (4) Polyisoprene

Which of the following is a thermosetting polymer? (1) Bakelite (2) NyIon6 (3) PVC (4) Buna-N

In a given polymers which is a condensation polymer.(1) Teflon(2) Neoprene(3) Buna - S(4) Nylon-6,6

Which of the following has minimum heat of hydrogenation.(i) ethene (ii) Propene (iii) cis-2-butene(iv) trans-2-butene

If Heat of hydrogenation of 1-butene is 30 Kcal then heat of hydrogenation of 1,3-butadiene is ? (i) 30(ii)60(iii) 57(iv) 25

Which is order of heat of hydrogenation for the following set of molecules :-

Reactivity order of the following alkenes for hydrochlorination (HCl) is (I) `CH_(2) = CH - Cl` (II) `(CH_(3))_(2)C=CH_(2)` (III) `CH_(2) = CH - CHO`A. `I gt II gt III`B. `II gt III gt I`C. `II gt I gt III`D. `III gt I gt II`

Which of the following is amorphous form of silica(1) Quartz(2) Kieselguhr(3) Tridymite(4) Cristobalite

The layer of atmosphere between 10 km to 50 km above the sea level is called as : (1) troposphere (2) thermosphere (3) stratosphere (4) mesosphere

The amorphous from of silica is : (1) kieselguhr (2) tridymite (3) cristobalite (4) quartz

Identify the compound 'X'(1) Toluidine(2) Benzamide(3) Para-Cresol(4) Oleic acid

Differentiate between somaclones and gametoclones. Who proposed the term somaclones?

An organic compound neither reacts with neutral ferric chloride solution nor with Fehling solution. It however, reacts with Grignard reagent and gives positive iodoform test. The compound is -

In the following compounds, the decreasing order of basic strength will be - (1) C2H5NH2 &gt; NH3 &gt; (C2H5)2NH (2) NH3 &gt; C2H5NH2 &gt; (C2H5)2NH (3) (C2H5)2NH &gt; NH3 &gt; C2H5NH2 (4) (C2H5)2NH &gt; C2H5NH2 &gt; NH3

If the quantum number for 5th electron of carbon are 2, 1, 0 and `1/2`.Then what is the correct set for its 6th electron ?A. `2,0,+1,+1/2`B. `2,1,0,+1/2`C. `2,1,+1,+1/2`D. `2,1,-1,-1/2`

For the reaction 2N2O5 → 4NO2+O2, the rate of reaction is(a) \(\frac{1}{2}\frac{d}{dt}\) [N2O5](b) 2\(\frac{d}{dt}\) [N2O5](c) \(\frac{1}{4}\frac{d}{dt}\) [NO2](d) 4 \(\frac{d}{dt}\) [NO2]

In the following compounds, the decreasing order of basic strength will be - (1) C2H5NH2 > NH3 > (C2H5)2NH (2) NH3 > C2H5NH2 > (C2H5)2NH (3) (C2H5)2NH > NH3 > C2H5NH2 (4) (C2H5)2NH > C2H5NH2 > NH3