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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.
| 9501. |
Toughness of a material is equal to area under ______ part of the stress-strain curve. (a) Elastic (b) Plastic (c) Both (d) None |
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Answer» Toughness of a material is equal to area under Both part of the stress-strain curve. |
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| 9502. |
Hydrostatic stress results in the following (a) Linear strain (b) Shear strain (c) Both linear and shear strains (d) None |
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Answer» The Correct option is (d) None |
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| 9503. |
The unique property of cast iron is (a) malleability (b) ductility (c) hardness (d) damping characteristics |
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Answer» (d) damping characteristics |
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| 9504. |
In twinning, a______ stress is required to initiate ,but a _____stress is required for propogation. (a) high, high (b) low,low (c) low, high (d) high ,low |
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Answer» In twinning, a high stress is required to initiate ,but a low stress is required for propogation. |
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| 9505. |
The molecular formula of Wilkinson catalyst, used in hydrogenation of alkenes isA. `Co(CO)_(3)`B. `(Ph_(3)P)_(3)RhCl`C. `[Pt(NH_(3))_(2)Cl_(2)]`D. `K[Ag(CN)_(2)]` |
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Answer» Correct Answer - B Wilkinston catalyst has molecular formula `(Ph_(3))P_(3)` RhCl and is used in hydrogenation of alkenes. |
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| 9506. |
If the doctors suspect peripheral neuropathy in the legs, where will the electrodes be placed?(a) At the buttocks(b) At the thighs(c) At the calves(d) At the feet |
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Answer» The correct answer is (d) At the feet To explain I would say: Peripheral neuropathy is a disease that mostly affects the peripherals of the body, like the palms or feet. The nerves have faced some sort of trauma or some damage which results in pain, numbness and tingling sensations. These symptoms are mostly expressed at the feet or at the palms so if the doctor suspects peripheral neuropathy at the legs, feet is where they will choose to put the electrodes. |
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| 9507. |
How many electrodes are normally needed for an NCV?(a) 12(b) 6(c) 2(d) 1 |
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Answer» The correct answer is (c) 2 To explain I would say: For a simple NCV test, 2 electrodes are enough. The electrodes are placed on two points in such a way that they lie on the same conduction path. One electrode is stimulated and the impulse generated travels down the path and the other electrode receives the signal. The time taken to travel the distance is noted along with the strength of the received signal. |
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| 9508. |
The impulses travel faster when _________(a) the axon has myelin sheath(b) the axon does not have myelin sheath(c) the cyton is small(d) the dendrites are longer |
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Answer» Correct option is (a) the axon has myelin sheath Easiest explanation: Myelin sheath is a sheath of fats covering the length of the axon with small breaks between them called the Nodes of Ranvir. Since the sheath is made of fats and fats are insulators, the impulses cannot travel in them. In a absence of myelin sheath, the impulses would have moved by depolarizing the adjacent point. However, since the fats of myelin sheath are blocking it, the impulses move by jumping between the Nodes of Ranvir. This increases the speed of conduction. |
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| 9509. |
The nerve impulses are actually _______(a) ATP(b) Action Potential(c) Re-polarization of nerves(d) Perception |
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Answer» Correct choice is (b) Action Potential Explanation: When a cell fibre is stimulated, that becomes the action potential that spreads all over and causes the body to function. This action potential is caused due to depolarization which travels throughout the body as nerve impulses. |
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| 9510. |
The correct path of the movement of nerve impulses in the following diagram is(A) Q → S → R → P(B) P → Q → R → S(C) S → R → Q → P(D) P → R → S → Q |
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Answer» (D) P → R → S → Q |
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| 9511. |
The functional groups present in propanol and propanal respectively are.a. -OH and -CHOb. -OH and -COOHc. -COP and COOHd. -CHO and -CO |
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Answer» a). -OH and -CHO |
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| 9512. |
पेप्टाइड क्या है |
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Answer» एमीनो अम्लों के अणुओं के अम्लीय -COOH समूह एवं क्षारीय -NH2 दोनों प्रकार के समूह होते है अत: एक एमिनो अम्ल का COOH समूह दूसरे एमीनो अम्ल के -NH2 से अभिक्रिया करके एमाइड या लवण बना लेते है , इसे पेप्टाइड कहते है। |
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| 9513. |
What are food preservatives? |
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Answer» Food preservatives are chemical substances are capable of inhibiting, retarding or arresting the process of fermentation, acidification or other decomposition of food by growth of micro organisms. Examples:
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| 9514. |
Why HCOOH does not give Hell-Volhard Zelinsky reaction but CH3COOH does? |
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Answer» CH3COOH contains α – hydrogen atom and hence gives HVZ reaction but HCOOH does not contain an α – hydrogen atom and hence does not give HVZ reaction. |
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| 9515. |
What are emulsions? What are their different types? Give example of each type. |
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Answer» The colloidal solution in which both the dispersed phase and dispersion medium are liquids is called an emulsion. There are two types of emulsions: |
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| 9516. |
Action of soap is due to emulsification and micelle formation. Comment. |
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Answer» The cleansing action of soap is due to emulsification and micelle formation. Soaps are basically sodium and potassium salts of long chain fatty acids, R-COO-Na+. The end of the molecule to which the sodium is attached is polar in nature, while the alkyl-end is non polar. Thus, a soap molecule contains a hydrophilic (polar) and a hydrophobic (nonpolar)part. Soaps are sodium & potassium salts of higher fatty acids. Eg: C17H35COONa oil & Grease in dirt adhere firmly to clothing and is undisturbed by washing in tap water. Soap acts as an Emulsifying agent and brings the Greasy dirt into colloidal dispersion the hydrocarbon chain of soap molecule is soluble in oil or grease. It dissolves in grease and encapsulates. It to form micelle. The anionic ends of chain protrude from droplets and interact with water molecules, preventing coalescence of droplets. |
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| 9517. |
What is demulsification? Name twon demulsifiers. |
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Answer» The process of decomposition of an emulsion into its constituent liquids is called demulsification. Examples of demulsifiers are surfactants, ethylene oxide, etc. |
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| 9518. |
Which of the following components is not a Micronutrient?(a) Zn^2+(b) Ca^2+(c) Na^+(d) Mg^2+ |
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Answer» Right choice is (d) Mg^2+ To elaborate: Elements used in large quantities by the plant are termed macronutrients, which can be further defined as primary or secondary. The primary nutrients include nitrogen (N), phosphorus (P), and potassium (K). These elements contribute to plant nutrient content, function of plant enzymes and biochemical processes, and integrity of plant cells. Deficiency of these nutrients contributes to reduced plant growth, health, and yield; thus they are the three most important nutrients supplied by fertilizers. The secondary nutrients include calcium (Ca), magnesium (Mg), and sulfur (S). |
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| 9519. |
What is the percentage composition of quartz in Western bentonite?(a) 5%(b) 10%(c) 15%(d) 20% |
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Answer» Correct choice is (b) 10% Easiest explanation: Bentonite is classified into 2 types, namely, Sodium montmorillonite and Calcium montmorillonite. Western bentonite also called Sodium montmorillonite is known to have a percentage composition 10% of quartz. |
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| 9520. |
What should be the accuracy of automatic moisture control for manufacturing sands?(a) ± 0.1%(b) ± 0.2%(c) ± 0.3%(d) ± 0.4% |
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Answer» The correct answer is (a) ± 0.1% To explain I would say: In any system, the accuracy in its working is considered to be one of the most essential features of that process. The accuracy of automatic moisture control for manufacturing sand must be ± 0.1%. |
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| 9521. |
What is the percentage composition of quartz in Southern bentonite?(a) 5%(b) 10%(c) 15%(d) 20% |
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Answer» Right answer is (c) 15% The explanation: Bentonite is classified into 2 types, namely, Sodium montmorillonite and Calcium montmorillonite. Southern bentonite also called as Calcium montmorillonite is known to have a percentage composition 15% of quartz. |
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| 9522. |
In synthetic sands of aluminium alloys, what is the bentonite percentage composition?(a) 2-5%(b) 3-5%(c) 4-5%(d) 5-6% |
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Answer» The correct choice is (c) 4-5% The explanation is: In synthetic sands of aluminium alloys, the bentonite percentage composition is calculated to be 4-5%. Whereas, in the case of green sands, the bentonite percentage is recorded to be around 3.5%. |
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| 9523. |
In magnesium alloys, what is the bentonite percentage composition?(a) 1%(b) 2%(c) 3%(d) 4% |
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Answer» Correct choice is (d) 4% Best explanation: In magnesium alloys, the bentonite percentage composition is calculated to be 4%. Whereas, in the case of green sands, the bentonite percentage is recorded to be around 3.5%. |
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| 9524. |
Arrange the acids `H_2SO_4,H_2SeO_4` and `H_2TeO_4` in decreasing order of their strength. |
| Answer» Acid strength: `H_2SO_4gtH_2SeO_4gtH_2TeO_4`. | |
| 9525. |
How is the presence of `SO_2` detected? |
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Answer» `SO_2` acts as a reducing agent hence `SO_2` turns pink coloured `KMnO_4` to colourless solution due to reduction of `MnO_4^(ɵ)` to `Mn^(2+)` `[MnO_4^(ɵ)+8H^(ɵ)+5e^(ɵ)toMn^(2+)+4H_2O]xx2` `underline[SO_2+2H_2OtoSO_4^(2-)+4H^(o+)2e^(ɵ)]xx5)` `underline(2MnO_4^(ɵ)+2H_2O+5SO_2to2Mn^(2+)+5SO_4^(2-)+4H^(o+))` |
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| 9526. |
The most stable resonating structure isA. `H_(2)N-overset(o+)(C )H-CH=CH-OH_(3)`B. `H_(2)overset(o+)(N)=CN-CH=CH-OCH_(3)`C. `H_(2)N-CN=CH-CH=overset(o+)(O)CH_(3)`D. `NH_(2)-overset(o+)(C )H-overset(Θ)(C )H-CH=overset(o+)(O)CH_(3)` |
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Answer» Correct Answer - B The most stable resonating ………… In `(2)` octet of all atoms is complete and positive charge present on less electronegative atom. |
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| 9527. |
In the chemical reaction, `CH_(3)CH_(2)NH_(2)+CHCI_(3)+3KOH rarr (A) + 3KCI+3H_(2)O` , the compounds `(A)` is :A. `CH_(3)NC`B. `C_(2)H_(5)NC`C. `CH_(3)CN`D. `CH_(3)CH_(2)CN` |
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Answer» Correct Answer - B In the chemical reaction…………… `CH_(3)CH_(2)NH_(2)+CHCI_(3)+3KOH rarr C_(2)H_(5)NC+3KCI+3H_(2)O` |
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| 9528. |
Why `PCl_3` fumes in moisture? |
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Answer» `PCl_3` undergoes hydrolysis in presence of moisture to form fumes of HCl. `PCl_3+3H_2OtoH_2PO_3+3HCl` |
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| 9529. |
The process of using an electric current to bring about chemical change is called electrolysis.Electrolysis is a processes of oxidation and reduction at the respective electrodes due to external current passed in the electrolyte. The product obtained during electrolysis depends on following factors. The nature of the electrolyte The concentration of electrolyte The nature of the electrode. Consider the electrolysis of following cell containing aq. solution of `CuSO_4,ZnCl_2` and `MBr_2` by using pure silver rod as a cathode and Pt electrode as anode.Assume that `M^(2+)` does not further oxidise and can not form complex with `NH_3` Assume no hydrolysis of any ion. `E_(Cu^(2+)//Cu)^(0)=0.35 V, E_(M^(2+)//M)^(0)=-0.10 V, E_(Zn^(2+)//Zn)^(0)=-0.76 V, E_(H_(2)O // H_2)^(0)=-0.828 V, E_(Ag^(+)//Ag)^(0)=0.80 V, (2.303RT)/F=0.06` If 36 mol of `NH_(3)(g)` is passed in electrolytic solution given in comprehension (assume no volume change by addition of `NH_(3)`),then what would be decreasing order of reduction potential of following : A. `M^(2+)gtCu^(2+)gtZn^(2+)`B. `Cu^(2+)gtM^(2+)gtZn^(2+)`C. `M^(2+)gtZn^(2+)gtCu^(2+)`D. `Cu^(2+)gtM^(2+)gtZn^(2+)` |
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Answer» Correct Answer - A `{:(Zn^(2+)+ 4NH_3 hArr Zn(NH_3)_4^(2+) " " K_f=1xx10^(9)),(1 " " 18),(1-x " " 18-4x-4y " " x):}` `Zn^(2+)=(Zn(NH_3)_4^(2+))/(K_f[NH_3]^4)=1/(10^9xx10^4)=10^(-)13` For `Zn^(2+)+2e^(-)toZn(s)` `E_(R.P)=-0.76-0.06/2"log"1/10^(-13)=-0.76-0.06xx13/2=-1.15 V` `{:(Cu^(2+)+ 4NH_3 hArr Cu(NH_3)_4^(2+) " " K_f=1xx10^(12)),(1 " " 18),(1-x " " 18-4x-4y " " y):}` `[Cu^(2+)]=(Cu(NH_3)_4^(2+))/(K_f[NH_3]^(4))=10^(-16)` For `Cu^(2+)+2e^(-)toCu(s)` `E_(R.P)=-0.34-0.06/2"log"1/10^(-16)=-0.34-0.06xx8=-1.14 V` |
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| 9530. |
The process of using an electric current to bring about chemical change is called electrolysis.Electrolysis is a processes of oxidation and reduction at the respective electrodes due to external current passed in the electrolyte. The product obtained during electrolysis depends on following factors. The nature of the electrolyte The concentration of electrolyte The nature of the electrode. Consider the electrolysis of following cell containing aq. solution of `CuSO_4,ZnCl_2` and `MBr_2` by using pure silver rod as a cathode and Pt electrode as anode.Assume that `M^(2+)` does not further oxidise and can not form complex with `NH_3` Assume no hydrolysis of any ion. `E_(Cu^(2+)//Cu)^(0)=0.35 V, E_(M^(2+)//M)^(0)=-0.10 V, E_(Zn^(2+)//Zn)^(0)=-0.76 V, E_(H_(2)O // H_2)^(0)=-0.828 V, E_(Ag^(+)//Ag)^(0)=0.80 V, (2.303RT)/F=0.06` After passing 20 amp current from battery for 28950 sec.the remaining conc. of ions in solution given in passage would be: (Assume current efficiency to be 100%) A. `[Cu^(2+)]=0.5M, [M^(2+)]=0.5M, [Zn^(2+)]=0.1M`B. `[Cu^(2+)]~~0M, [M^(2+)]=0.5M, [Zn^(2+)]=0.5M`C. `[Cu^(2+)]=0.5M, [M^(2+)]=0.5M, [Zn^(2+)]=0.5M`D. `[Cu^(2+)]~~0M, [M^(2+)]=0.5M, [Zn^(2+)]=1 M` |
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Answer» Correct Answer - D Deposition order `CugtMgtZn` Cu required `implies (Ixxt)/96500=w/E` `20xxt=1xx2xx2xx96500` t=19300 sec. In 28950-19300=9650 sec `M^(2+)`, will deposit as M. mole of `Mxx2=(20xx9650)/96500` mole of M deposit =1 Initial mole of `M^(2+)=1xx2`, remain `M^(2+)` moles =2-1=1 , `[M^(2+)]=1/2=0.5` |
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| 9531. |
Which one of the following compounds in a peroxide?A. `KO_(2)`B. `BaO_(2)`C. `MnO_(2)`D. `NO_(2)` |
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Answer» Correct Answer - B `KO_(2)` is `K^(+)O_(2)^(-)` i.e., superoxide `BaO_(2)` is `Ba^(2+)O_(2)^(2-)` i.e., peroxide `MnO_(2)` is `Mn^(4+)O^(2-)` i.e., monoxide `NO_(2)` is `N^(4-)O^(2-)` i.e., monoxide |
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| 9532. |
Which of the following is thermally stable carbonate?A. `Li_(2)CO_(3)`B. `Na_(2)CO_(3)`C. `BeCO_(3)`D. `CaCO_(3)` |
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Answer» Correct Answer - B `CaCO_(3)overset(Delta)toCaO+CO_(2)` `BeCO_(3)overset(Delta)toBeO+CO_(2)` `Li_(2)CO_(3)overset(Delta)toLi_(2)O+CO_(2)` |
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| 9533. |
Which of the following statement is correct with respect to the metal carbonyls of `I^(st)` transition series ?A. As M - `Cpi` bonding increases , the C-O bond becomes weakerB. As positive charge on the central metal atom increases , the C-O bond becomes weakerC. As electron density on the central metal atom increases, the C-O bond becomes weakerD. (A) and (C ) both |
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Answer» Correct Answer - D Order of C-O bond strength, `[Mn(CO)_6]^(+) gt [Cr(CO)_6]gt [V(CO)_6]^(-)gt [Ti(CO)_6]^(2-) gt and [Ni(CO)_4] gt [Co(CO)_4]^(-) gt [Fe(CO)_4]^(2-)`. (A)True statement. (B)As + ve charge on the central metal atom increases, the less readily the metal can donate electron density into the `pi^(**)` orbitals of CO ligand to weaken the C-O bond. (C )In the carbonylate anions, the metal has a greater electron density to be dispersed, with the result that M-`Cpi` bonding is enhanced and the C-O bond is diminished in strength. |
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| 9534. |
A fuel cell is a cell that is continously supplied with an oxidant and a reductant so that if can deliver a current indefinitely. Fuel cells offer the possibility of achieving high thermodynamic efficiency in the conversion of Gibbs energy into mechanical work.Internal combustion engines at best convert only the fraction `(T_2-T_1)//T_2` of the heat of combustion into mechanical work. While the thermodynamic efficiency of the fuel cell is given by, `eta=(DeltaG)/(DeltaH)`, where `DeltaG` is the Gibbs energy change for the cell reaction and `DeltaH` is the enthalpy change of the cell reaction.A hydrogen-oxygen fuel cell may have an acidic or alkaline electrolyte. `Pt|H_2(g)|H^(+)(aq.)||H_2O(l)|O_(2)(g)|Pt , (2.303 RT)/F=0.06` The above fuel cell is used to produce constant current supply under constant temperature & 30 atm constant total pressure conditions in a cylinder.If 10 moles `H_2` and 5 moles of `O_2` were taken initially. Rate of consumption of `O_2` is 10 milli moles per minute. The half-cell reactions are `1/2O_2(g)+2H^+(aq)+2e^(-)toH_2O(l) E^(@)=1.246 V` `2H^+(aq)+2e^(-) to H_2(g) E^(@)=0` To maximize the power per unit mass of an electrochemical cell, the electronic and electrolytic resistances of the cell must be minimized.Since fused salts have lower electolytic resistances than aqueous solutions, high-temperature electrochemical cells are of special interest for practical applications. The above fuel cell is used completely as an electrolytic cell with Cu voltameter of resistance `26.94 Omega` using Pt electrodes. Initially Cu voltameter contains 1 litre solution of `0.05 M CuSO_4 [H^(+)]` in solution after electrolysis (Assuming no changes in volume of solution.)A. 0.015 MB. 0.03 MC. 0.025 MD. 0.01 M |
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Answer» Correct Answer - A `i=V/R=1.3/26.94=0.04825 A` time of electrolysis `=5/(10xx10^(-3))=500` minutes. `Cu^(2+)(aq)+H_2OtoCu^(+)(aq)+1/2O_2+2H^(+)(aq)` `:.` moles of `H^+` formed `=(ixxt)/F=(0.04825xx500xx60)/96500=0.015 M` |
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| 9535. |
A fuel cell is a cell that is continously supplied with an oxidant and a reductant so that if can deliver a current indefinitely. Fuel cells offer the possibility of achieving high thermodynamic efficiency in the conversion of Gibbs energy into mechanical work.Internal combustion engines at best convert only the fraction `(T_2-T_1)//T_2` of the heat of combustion into mechanical work. While the thermodynamic efficiency of the fuel cell is given by, `eta=(DeltaG)/(DeltaH)`, where `DeltaG` is the Gibbs energy change for the cell reaction and `DeltaH` is the enthalpy change of the cell reaction.A hydrogen-oxygen fuel cell may have an acidic or alkaline electrolyte. `Pt|H_2(g)|H^(+)(aq.)||H_2O(l)|O_(2)(g)|Pt , (2.303 RT)/F=0.06` The above fuel cell is used to produce constant current supply under constant temperature & 30 atm constant total pressure conditions in a cylinder.If 10 moles `H_2` and 5 moles of `O_2` were taken initially. Rate of consumption of `O_2` is 10 milli moles per minute. The half-cell reactions are `1/2O_2(g)+2H^+(aq)+2e^(-)toH_2O(l) E^(@)=1.246 V` `2H^+(aq)+2e^(-) to H_2(g) E^(@)=0` To maximize the power per unit mass of an electrochemical cell, the electronic and electrolytic resistances of the cell must be minimized.Since fused salts have lower electolytic resistances than aqueous solutions, high-temperature electrochemical cells are of special interest for practical applications. If `lambda_m^(oo)(Cu^(2+))=0.01S m^(2) "mole"^(-1),lambda_m^(oo)(H^(+))=0.035S m^(2) "mole"^(-1) and lambda_m^(oo)(SO_(4)^(2-))=0.016S m^(2) "mole"^(-1)`,specific conductivity of resulting solution left in copper voltameter after above electrolysis isA. 2.57S `m^(-1)`B. 1.75S `m^(-1)`C. 1.525S `m^(-1)`D. 2.25 S `m^(-1)` |
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Answer» Correct Answer - B In resulting solution, `[Cu^(2+)]=0.05-0.0075=0.0425 M, [H^+]=0.015 M and [SO_4^(2-)]=0.05 M` `K=K_(Cu^(2+))+K_(H^+)+K_(SO_4^(2-))=(lambda_(Cu^(2+))^ooxx[Cu^(2+)])/1000+(lambda_(H^+)^(oo)xx[H^+])/1000+(lambda_(SO_4^(2-))^(oo)xx[SO_4^(2-)])/1000` `(0.01xx10^4xx0.0425)/1000+(0.035xx10^4xx0.015)/1000+(0.016xx10^4xx0.05)/1000=0.00425+0.00525+0.008=0.0175 S cm^(-1)` `=1.75 Sm^(-1)` |
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| 9536. |
The molar conductance of NaCl varies with the concentration as shown in the following table and all values follows the equation. `lambda_(m)^(c)=lambda_(m)^(oo)-bsqrt(C)` where `lambda_(m)^(c)`= molar specific conductance `lambda_(m)^(oo)=` molar specific conductance at infinite dilution C=molar concentration When a certain conductivity cell (C) was filled with 25`xx10^(-4)(M) NaCl` solution, the resistance of the cell was found to be 1000 ohm. At infinite dilution, conductance of `Cl^(-)` and `SO_(4)^(2-)` are `80ohm^(-1) cm^(2) "mole"^(-1)` and `160ohm^(-1) cm^(2) "mole"^(-1)` respectively. What is the molar conductance of NaCl at infinite dilution?A. `147 "ohm"^(-1)cm^2"mole"^(-1)`B. `107 "ohm"^(-1)cm^2"mole"^(-1)`C. `127 "ohm"^(-1)cm^2"mole"^(-1)`D. `157 "ohm"^(-1)cm^2"mole"^(-1)` |
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Answer» Correct Answer - C `lambda_m^C=lambda_m^oo-bsqrtC` when `C_1=4xx10^(-4) lambda_m^C=107` and when `C_2=9xx10^(-4) lambda_m=97` so `107=lambda_m^oo-bxx2xx10^(-2)`...(1) `97=lambda_m^oo - bxx3xx10^(-2)`...(2) b=1000 `lambda_m=lambda_m^oo-bsqrtC` `lambda_m^oo=lambda_m+bsqrtC` `=107xx10^3xx2xx10^(-2)` `lambda_m^oo=127 "ohm"^(-1)cm^(2)"mole"^(-1)` |
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| 9537. |
Match Matrix `{:("Column I","Column II"),((A)Zn|Zn^(2+)( C)||Zn^(2+)(2C)|Zn,(p)"Spontaneous cell reaction"),((B)H_2(P)|HCl(1N)||H_2SO_4(1N)|H_2(P),(q)"Working cell representation"),(( C)Cu|Cu^(2+)(0.01 M)||Ag^(+)(0.1M)|Ag,(r)"Concentration of cation in cathodic compartment increases upto equilibrium"),((D)Ag|AgCl|(KCl, 0.1 M)||Ag^(+)(0.01 M)|Ag,(s)"Concentration cell"),(,(t)"Concentration of"Cl^(-)"in anodic compartment decreases"):}` |
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Answer» Correct Answer - A`to`p,q,s ; B`to`r,s ; C`to`p,q ; D`to`p,q,s,t `E_("cell")=-0.0591/2"log"C/(2C)=8.89xx10^(-3)` Spontaneous, cell works, conc cell `E_("cell")=-0.0591 "log"1/0.5 =- 0.0591` Non spontaneous cell will not work conc cell `E_("cell")=-0.0591/2"log"0.01/0.1^2-0.74+0.8=0.06` Spontaneous cell works `E_("cell")=-0.0591/1"log"(Cl^-)/(K_(sp))-0.0591/1"log"1/([Ag^+])` `=0.0591/2"log"(0.1xx0.1)/(K_(sp(AgCl))=+ve` Spontaneous cell works conc cell For anode `Ag(s)+Cl^(-)(aq)toAgCl(s)+e^-` |
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| 9538. |
Which of the following statements is correct with respect to the metal carbonyls of `I^(st)` transition series?A. As `M-Cpi` bonding increase, the `C-O` bond length increases.B. As positive charge on the central metal atom increases, the `C-O` bond length increases.C. As electron density on the central metal atom increases, the `C-O` bond length increases.D. (1) and (3) both |
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Answer» Correct Answer - D order of `C-O` bond strength: `[Mn(CO)_(6)]^(+)gt[Cr(CO)_(6)]gt[V(CO)_(6)]^(-)gt[Ti(CO)_(6)]^(2-)` and `[Ni(CO)_(4)]gt[Co(CO)_(4)]gt[Fe(CO)_(4)]^(2-)` (1). True statement (2). `As+` ve charge on te central metal atom increases, the less readily the metal can donate electron density into the `pi^(*)` orbitals of CO ligand to weaken the `C-O` bond. (3). In the corbonylate anions, the metal has a greater electron density to be dispersed, with the result that `M-Cpi` bonding is enhanced and the `C-O` bond is diminished in strength. |
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| 9539. |
Durinh electrlysis of an aqueous solution of `CuSO_(4)` using copper electrodes, if `2.5g` of `Cu` is deposited at cathode, tehn at anodeA. 890 mL of `O_(2)` at STP is liberatedB. 445 mL of `O_(2)` at STP is liberatedC. 445 mL of `O_(2)` at STP is liberatedD. 2.5 g of copper is deposited |
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Answer» Correct Answer - D Copper electrodes are reactive electrodes. `implies` At anode: `CutoCu^(2+)+2e^(-)` At cathode: `Cu^(2+)+2e^(-)toCu` So, mass of Cu deposited on cathode `=` mass of Cu decreased at anode. |
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| 9540. |
The molar conductance of NaCl varies with the concentration as shown in the following table. And all values follows the equation `lambda_m^C=lambda_m^oo-bsqrtC` Where `lambda_m^C`=Molar specific conductance `lambda_m^oo`=Molar specific conductance at infinite direction C=Molar concentration `{:("Molar Concentration of NaCl","Molar Conductance inohm"^(-1)cm^(2)"mole"^(1)),(4xx10^(-4),107),(9xx10^(-4),97),(16xx10^(-4),87):}` When a certain conductivity cell (C ) was filled with `25xx10^(-4)` (M) NaCl solution.The resistance of the cell was found to be 1000 ohm.At infinite dilution, conductance of `Cl^(-)` and `SO_(4)^(-2)` are 800 `"ohm"^(-1) cm^(2)"mole"^(-1) and 160 "ohm"^(-1) cm^(2)"mole"^(-1)` respectively. What is the cell constant of the conductivity cell ( C) ?A. `0.385 cm^(-1)`B. `3.85 cm^(-1)`C. `38.5 cm^(-1)`D. `0.1925 cm^(-1)` |
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Answer» Correct Answer - D For `25xx10^(-4)` (M) NaCl solution `lambda_m=lambda_m^oo-bsqrtC` `lambda_m=127-10^3(25xx10^(-4))^(1//2)` `lambda_m=127-10^(3)xx5xx10^(-2)` `lambda_m=77` But `lambda_m=(Kxx1000)/M " " K=(l/a)xx1/R` `lambda_m=(l/a)xx1/Rxx1000/M` `lambda_m`=[Cell constant]`xx1000/(RxxM)` `implies `77=[Cell constant]`xx1000/(1000xx25xx10^(-4))` Cell constant `=77xx25xx10^(-4)=0.1925 cm^(-1)` |
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| 9541. |
The molar conductance of NaCl varies with the concentration as shown in the following table. And all values follows the equation `lambda_m^C=lambda_m^oo-bsqrtC` Where `lambda_m^C`=Molar specific conductance `lambda_m^oo`=Molar specific conductance at infinite direction C=Molar concentration `{:("Molar Concentration of NaCl","Molar Conductance inohm"^(-1)cm^(2)"mole"^(1)),(4xx10^(-4),107),(9xx10^(-4),97),(16xx10^(-4),87):}` When a certain conductivity cell (C ) was filled with `25xx10^(-4)` (M) NaCl solution.The resistance of the cell was found to be 1000 ohm.At infinite dilution, conductance of `Cl^(-)` and `SO_(4)^(-2)` are 800 `"ohm"^(-1) cm^(2)"mole"^(-1) and 160 "ohm"^(-1) cm^(2)"mole"^(-1)` respectively. If the cell ( C) is filled with `5xx10^(-3) (N)Na_2SO_4` the observed resistance was 400 ohm. What is the molar conductance of `Na_2SO_4` ?A. `19.25 ohm^(-1) cm^(2) "mole"^(-1)`B. `96.25 ohm^(-1) cm^(2) "mole"^(-1)`C. `385 ohm^(-1) cm^(2) "mole"^(-1)`D. `192.5 ohm^(-1) cm^(2) "mole"^(-1)` |
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Answer» Correct Answer - D For `Na_2SO_4` solution `K=(l/a)xx1/R=0.1925/400=4.81xx10^(-4) ohm^(-1)cm^(-1)` `lambda_m=(Kxx1000)/M=(4.81xx10^(-4)xx1000)/(5/2xx10^(-3))` `lambda_m(Na_2SO_4)=192.4 ohm^(-1) cm^2 "mole"^(-1)` |
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| 9542. |
The molar conductance of NaCl varies with the concentration as shown in the following table and all values follows the equation `lambda_m^( C)=lambda_m^(oo)-bsqrtC` where `lambda_(m)^( C)`=molar specific conductance `lambda_(m)^(oo)`=molar specific conductance at infinite dilution C=molar concentration `{:("Molar Concentration of NaCl","Molar Conductance" "In" "ohm"^(-1)cm^(2)"mole"^(-1)),(4xx10^(-4),107),(9xx10^(-4),97),(16xx10^(-4),87):}` When a certain conductivity cell (C) was filled with `25xx10^(-4)`(M) NaCl solution.The resistance of the cell was found to be 1000 ohm.At Infinite dilution, conductance of `Cl^(-)` and `SO_4^(-2)` are `80 ohm^(-1) cm^(2) "mole"^(-1) and 160 ohm^(-1) cm^2 "mole"^(-1)` respectively. If the cell ( C) is filled with `5xx10^(-3)(N)Na_(2)SO_(4)` the obserbed resistance was 400 ohm.What is the molar conductance of `Na_(2)SO_(4)`.A. `19.25 "ohm"^(-1)cm^2"mole"^(-1)`B. `96.25 "ohm"^(-1)cm^2"mole"^(-1)`C. `385 "ohm"^(-1)cm^2"mole"^(-1)`D. `192.5 "ohm"^(-1)cm^2"mole"^(-1)` |
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Answer» Correct Answer - D `sigma=(Mlambda)/(1000 G)=(MlambdaR)/1000implies lambda=(1000sigma)/(MR)` `lambda=((1000xx0.1925)/(5xx10^(-)3))/2xx400=192.5` |
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| 9543. |
The electrode potentials for `Cu^(2+)+e^(-)toCu^(+)` and `Cu^(+)e^(-)toCu_(s)` are `+0.15`V and `+0.50V` respectively the value of `E_((Cu^(2+))/(Cu))^(@)` will be?A. 0.500 VB. 0.325 VC. 0.650 VD. 0.150 V |
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Answer» Correct Answer - B `Cu^(2+)+1e^(-)toCu^(+)` `E_(1)^(0)=0.15vDeltaG_(1)^(0)=-n_(7)E_(1)^(0)F` underline(Cu^(+)+e^(-)toCu_(s) E_(2)^(0)=0.50vDeltaG_(2)^(0)=-n_(7)E_(2)^(0)F)` `Cu^(2+)+2e^(-)toCuDeltaG^(@)=DeltaG_(1)^(@)+DeltaG_(2)^(@)` `(-1)nEF=(-1)n_(1)E_(1)^(0)F+(-1)n_(2)E_(2)^(0)F` `E=(n_(1)E_(1)^(0)+n_(2)E_(2)^(0))/(n)=(0.15xx1+0.50xx1)/(2)=0.325V` |
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| 9544. |
Calculate the useful work of the reaction Ag(s)+`1//2Cl_2(g)to AgCl(s)` Given `E_(C l^(-)//C l^(-))^(@)=+1.36 V, E_(Ag|AgCl|Cl^(-))^(@)=0.22 V` If `P_(Cl_(2))`=1 atm and T=298 KA. 110 kJ/molB. `220 "kJ"//"mol"`C. `55 "kJ"//"mol"`D. `1000 "kJ"//"mol"` |
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Answer» Correct Answer - A `(1) AgCl(s)+e toAg(s)+Cl^(-) " " E^@=0.22 V` `(2)1//2Cl_2+e to Cl^(-) " " E^@=1.36 V` we get `Ag(s) + 1//2 Cl_2(g) to AgCl(s) " " E_("cell")^@=0.14 V` `therefore DeltaG=-nEF^@=-(1)(96500)(1.14)=-110` kJ/mol |
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| 9545. |
State properties of carbon which lead to a very large number of carbon compounds.A. CatenationB. tetravalencyC. Both a and bD. none of these |
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Answer» Correct Answer - C |
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| 9546. |
What is the difference in the molecular formula of any two consecutive members of a homologous series of organic compounds?A. `CH_2`B. `CH_3CH_2`C. `CH_3`D. none of these |
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Answer» Correct Answer - A |
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| 9547. |
The general formula of both aldehyde and ketone is –(A) CnH2n+2O (B) CnH2nO (C) CnH2n-2O (D) CnH2n+4O |
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Answer» Correct answer is (B) CnH2nO |
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| 9548. |
Regarding nephrogenic systemic fibrosis (NSF): a. It usually involves the trunk first and spreads distally to the extremities b. It can occur in patients with normal kidney function c. The highest risk is posed by gadolinium compounds with a cyclical structure d. Most of the described cases are attributed to gadodiamide and gadopentetic acid e. In patients with severe renal impairment (estimated glomerular filtration rate (eGFR) <30 ml min-1 per 1.73 m2 ), all gadolinium-based contrast agents are contraindicated |
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Answer» a. False. NSF starts as fibrosis of the skin and connective tissue of the extremities. b. False. There are no known cases of NSF in patients with normal kidney function. c. False. NSF is thought to be associated with the release of free Gd3þ from the chelate. This is most likely to happen with linear non-ionic compounds, and is least likely with cyclic compounds. d. True. Most cases have been associated with gadiodiamide (Omniscan). A small number of cases have been associated with gadopentetic acid (Magnevist). e. False. According to the guidance from the UK Medicine and Healthcare products Regulatory Agency (MHRA), such patients should not be given gadodiamide and gadopentetic acid. In the case of other gadolinium-containing compounds, ‘careful consideration should be given’. |
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| 9549. |
How are involuntary actions and reflex actions different from each other? |
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Answer» Involuntary actions cannot be consciously controlled. For example, we cannot consciously control the movement of food in the alimentary canal or pumping of blood through heart. These actions are however directly under the control of the brain. On the other hand, the reflex actions such as closing of eyes immediately when bright light is focused show sudden response and do not involve any thinking. This means that unlike involuntary actions, the reflex actions are not under the control of brain. |
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| 9550. |
Which organ is affected by mastitis disease? a) Skin b) Mammary glands c) Bones d) Legs |
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Answer» Correct answer is b) Mammary glands |
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