InterviewSolution
Saved Bookmarks
InterviewSolution
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.
| 1. |
The radiation from naturally occuring radioactive substance as seen after deflection by a magnetic field in one direction are :A. `alpha` -raysB. `beta`-raysC. both `alpha` and `beta` raysD. either `alpha` or `beta`-rays |
|
Answer» Correct Answer - D |
|
| 2. |
Arrhenius studies the effect of temperature on the rate of a reaction and postulted that rate constant varies with temperature exponentially as `k=Ae^(E_(a)//RT)` . Thuis method is generally used for finding the activation energy of a reaction. Keeping temperature constant, the effect of catalyst on the activation energy has also been studied. If the rate of reaction doubles for `10^(@)C` rise of temperature form 290K to 300K, the activation energy of the reaction will be approximately :A. 40 Kcal `mol^(-1)`B. 12 Kcal `mol^(-1)`C. 60 Kcal `mol^(-1)`D. 70 Kcal `mol^(-1)` |
|
Answer» Correct Answer - B |
|
| 3. |
Arrhenius studies the effect of temperature on the rate of a reaction and postulted that rate constant varies with temperature exponentially as `k=Ae^(E_(a)//RT)` . Thuis method is generally used for finding the activation energy of a reaction. Keeping temperature constant, the effect of catalyst on the activation energy has also been studied. The pre-exponetial factor in the Arrhenius equation of a first order reaction has the unit :A. mol `L^(-1)s^(-1)`B. L `mol^(1)s^(-1)`C. `s^(-1)`D. `dimensionaless |
|
Answer» Correct Answer - C |
|
| 4. |
Arrhenius studies the effect of temperature on the rate of a reaction and postulted that rate constant varies with temperature exponentially as `k=Ae^(E_(a)//RT)` . Thuis method is generally used for finding the activation energy of a reaction. Keeping temperature constant, the effect of catalyst on the activation energy has also been studied. If x is the fraction of molecules having energy greater than `E_(a)` it will be given by :A. `x=-(E_(a))/(RT)`B. In `x=-(E_(a))/(RT)`C. `x=e^(E_(a)//RT)`D. Any of these |
|
Answer» Correct Answer - B |
|
| 5. |
Emission of `beta` -particle is equivatent to:A. increase of one proton onlyB. decrease of one neutron onlyC. both (a) and (b)D. none of these |
|
Answer» Correct Answer - C |
|
| 6. |
Size of nucleus was obtained by the equation `r=R_(0)A^(1//3)` , Where r is the radius of nucleus of mass no A. and `R_(0)` is a constant whose valie is equal to `1.5xx10^(-15)` metre. (Given : 1 amu = `1.66xx10^(-24)g`) What is the density of a nucleus of mass number A ?A. `(4)/(3)pi(1.5xx10^(-15))^(3)` AB. `1.17xx10^(17)kg//cm^(3)`C. `1.17xx10^(-17)kg//m^(3)`D. none of these |
|
Answer» Correct Answer - B |
|
| 7. |
Radioactive disintegration is a first order reaction and its rate depends only upon the nature of nucleus and does not depend upon external factors like temperature and pressure. The rate of radioactive disintegration (Activity) is represented as `-(dN)/(dt)=lambdaN` Where `lambda=` decay constant, N= number of nuclei at time t, `N_(0)` =intial no. of nuclei. The above equation after integration can be represented as `lambda=(2.303)/(t)log((N_(0))/(N))` Calculate the half-life period of a radioactive element which remains only `1//16` of its original amount in `4740` years:A. 1185 yearsB. 2370 yearsC. `52.5` yearsD. none of these |
|
Answer» Correct Answer - A |
|
| 8. |
Radioactive disintegration is a first order reaction and its rate depends only upon the nature of nucleus and does not depend upon external factors like temperature and pressure. The rate of radioactive disintegration (Activity) is represented as `-(dN)/(dt)=lambdaN` Where `lambda=` decay constant, N= number of nuclei at time t, `N_(0)` =intial no. of nuclei. The above equation after integration can be represented as `lambda=(2.303)/(t)log((N_(0))/(N))` What is the activity in Ci (curie) of 1.0mole plutonium `-239` ? `(t_(1//2)=24000` yeasrs)A. `1.49` CiB. `14.9` CiC. `5.513xx10^(11)` CiD. `None of these |
|
Answer» Correct Answer - B |
|
| 9. |
Radioactive disintegration is a first order reaction and its rate depends only upon the nature of nucleus and does not depend upon external factors like temperature and pressure. The rate of radioactive disintegration (Activity) is represented as `-(dN)/(dt)=lambdaN` Where `lambda=` decay constant, N= number of nuclei at time t, `N_(0)` =intial no. of nuclei. The above equation after integration can be represented as `lambda=(2.303)/(t)log((N_(0))/(N))` Half-life period of `U^(2.5xx10^(5)` years. In how much thime will the amount of `U^(237)` remaining be only `25%` of the original amount ?A. `2.5xx10^(5)` yearB. `1.25xx10^(5)` yearsC. `5xx10^(5)` yearsD. none of these |
|
Answer» Correct Answer - C |
|
| 10. |
Which of the following is incorrect statement ?A. Stoichiometry of a reaction tells about the order of the elementry reaction.B. For a zero order reaction. Reate and the rate constant are identical .C. A zero order reaction is controlled by factors other than concentration of reactantsD. A zero order reaction is an elementary reaction |
|
Answer» Correct Answer - D |
|
| 11. |
Which of the following statement is incorrect?A. A second order reaction must be a bimolecular elementry reactionB. A bimolecular elementry reaction must be a second order reactonC. Zero order reaction must be a complex reactionD. First order reaction may be complex or elementary reaction |
|
Answer» Correct Answer - A |
|
| 12. |
Which of the following statement is incorrect?A. Unit of rate of disapearence is `Ms^(-1)`B. Unit if rate of reaction is `Ms^(-1)`C. Unit of rate constant k depends upon orderD. Unit of k for first order reaction is `Ms^(-1)` |
|
Answer» Correct Answer - D |
|
| 13. |
Two radio isotopes A and B of atomic mass X and Y are mixed in equal amount by mass. After 20 days , their mass ratio is found to be `1:4`. Isotope A has a half-life of 1 day. The half-life of isotope B is :A. `1.11 (Y)/(X)` daysB. `0.11 (X)/(Y)` dayC. 0.6237 dayD. 1.10 day |
|
Answer» Correct Answer - D |
|
| 14. |
The amount of `._(6)^(14)C` isotope in a piece of wood is found to one fourth (1/4) of that present in a fresh piece of wood. Calculate the age of the piece of wood `(t_(12) "of "_(6)^(14)C=5770 "years")`A. 7999 yearB. 11540 yearC. 16320 yearD. 23080 year |
|
Answer» Correct Answer - B |
|
| 15. |
The radioactive decay `._(83)^(211)Birarr_(81)^(207)Ti` , takes place in 100L closed vessel at `27^(@)C` Starting with 2 mols of `_(83)^(211)Bi(t_(1//2)=130sec)` , the presuure development in the vessel after 520 sec will be:A. `1.875` atmB. `0.2155atm`C. `0.4618` atmD. `4.618` atm |
|
Answer» Correct Answer - C |
|
| 16. |
Indium -112 is radioactive and has a very short half-life (`t_(1//2)=14` min). Its decay constant and average life are repectively:A. 0.0495 `"min"^(-1)`, 9.7 minB. `0.495 "min"^(-1)`, 20.2 minC. `9.7 "min"^(-1)`,20.2 minD. `0.0495 "min"^(-1)`,20.2 min |
|
Answer» Correct Answer - D |
|
| 17. |
A radioactive isotope X with half-life of `693xx10^(9)` years decay to Y which is stable. A sample of rock from of the moon was found to contain both the elements X Y in the mole ratio `1:7` . What is the age of the rock ?A. `2.079xx10^(10)` yearsB. `1.94xx10^(10)` yearsC. `1.33xx10^(9)` yearsD. `10^(10)` years |
|
Answer» Correct Answer - A |
|
| 18. |
The half-life of `._(6)^(14)C` is 5730 year. What fraction of its original `C^(14)` would left after 22920 year of storage?A. 0.5B. 0.25C. 0.125D. 0.0625 |
|
Answer» Correct Answer - D |
|
| 19. |
Each question contains STATEMENTS-1 (Assertion) and STATEMENT -2 (Reason). Examine the statements carefully and mark the correct answer according to the instructions given below: STATEMENT-1: Nucleus does not contain fee electrons, yet it emit beta-particles STATEMENT-2: At high n/p ratio, one neutron supposed to give 1 proton and 1 `e^(-)(beta)`.A. If both the statements are TRUE and STATEMENT-2 is the correct explanation of STATEMENT-1B. If both the statement are TRUE but STATEMENT-2 is NOT the correct explanation of STATEMENT-1C. If STATEMENT-1 is TRUE and STATEMENT-2 is FALSED. If STATEMENT-1 is FALSE and STATEMENT-2 is TRUE |
|
Answer» Correct Answer - A |
|
| 20. |
For a hypothetical reaction, `A+3BrarrP" " DeltaH=-ex` Kj/ "mole" of A ` &Mrarr2Q+R" " DeltaH=+xx` kJ/ "mole" of M These reactions are carried simultaneously in a reactor such that temperature is not changing If rate of disppearance of B is y `sec^(-1)` then rate of formation (in M`sec^(-1))` of Q is :A. `(2)/(3)y`B. `(3)/(2)y`C. `(4)/(3)y`D. `(3)/(4)y` |
|
Answer» Correct Answer - C |
|
| 21. |
The unit of rate constant of elementary reaction depends upon theA. temperature of the reactionB. concentration of recytantsC. activation energy of the reactionD. Molecularity of the reaction |
|
Answer» Correct Answer - D |
|
| 22. |
The forward rate constant for the elementary reversible gaseous reaction `C_(2)H_(6)ltimplies2CH_(3) "is" 1.57xx10^(-3)s^(-1)at 100 K` What is the rate constant for the backward reaction at this temperature if `10^(-4)` moles of `CH_(3)` and 10 moles of `C_(2)H_(6)` are present in a 10 litre vessel at equilibrium .A. `1.57xx10^(9) L "mole"^(-1)s^(-1)`B. `1.57xx10^(10) L "mole"^(-1)s^(-1)`C. `1.57xx10^(11) L "mole"^(-1)s^(-1)`D. `1.57xx10^(7) L "mole"^(-1)s^(-1)` |
|
Answer» Correct Answer - D |
|
| 23. |
The differential rate law equation for the elementary reaction `A+2Boverset(k)to3C`, isA. `-(d[A])/(dt)=(d[B])/(dt)=(d[C])/(dt)=k[A][B]^(2)`B. `-(d[A])/(dt)=(1)/(2)(d[b])/(dt)=(1)/(3)(d[C])/(dt)=k[A]^(2)[B]`C. `-(d[A])/(dt)=(1)/(2)(d[b])/(dt)=(1)/(3)(d[C])/(dt)=k[A][B]^(2)`D. None of these |
|
Answer» Correct Answer - C |
|
| 24. |
The rate of a reaction is expressed in different ways as follows: `+(1)/(2)(d[C])/(dt)=-(1)/(3)(d[D])/(dt)=+(1)/(4)(d[A])/(dt)=-(d[B])/(dt)` the reaction isA. `4A+Bto2C+3D`B. `B+3Dto4A+2C`C. `A+BtoC+D`D. `B+DtoC+D` |
|
Answer» Correct Answer - B |
|
| 25. |
For the reaction `2AtoB+3C`, if `-(d[A])/(dt)=k_(1)[A]^(2),-(d[B])/(dt)=k_(2)[A]^(2),-(d[C])/(dt)=k_(3)[A]^(2)` the correct reaction between `k_(1),k_(2)` and `k_(3)` is :A. `k_(1)=k_(2)=k_(3)`B. `2k_(1)=k_(2)=3k_(2)`C. `4k_(1)=k_(2)=3k_(2)`D. `(k_(1))/(2)=k_(2)=(k_(3))/(3)` |
|
Answer» Correct Answer - D |
|
| 26. |
In the reaction , `A+2Bto6C+2D`, if the initial rate `-(d[A])/(dt)` at t= 0 is `2.6xx10^(-2)Msec^(-1)`, what will be the value of `-(d[B])/(dt)` at t=0?A. `8.5xx10^(-2)Msec^(-1)`B. `2.5xx10^(-2)Msec^(-1)`C. `5.2xx10^(-2)Msec^(-1)`D. `7.5xx10^(-2)Msec^(-1)` |
|
Answer» Correct Answer - C |
|
| 27. |
Select the rate law that corresponds to the datashown for the reaction `A+BtoC` `{:(,Exp.,[A],[B],Rate),(,1,0.012,0.035,0.10),(,2,0.024,0.070,0.80),(,3,0.024,0.035,0.10),(,4,0.012,0.070,0.80):}`A. Rate=`k[B]^(3)`B. Rate=`k[B]^(4)`C. Rate k=`[A][B]^(3)`D. Rate =k`[A]^(2)[B]^(2)` |
|
Answer» Correct Answer - A |
|
| 28. |
The activation energy of the reaction, `A+BtoC+D+38` kcal is 20 kcal. What would be the activation energy pof the following reaction. `C+DtoA+B`A. 20 kcalB. `-20 kcal`C. 18 kcalD. 58 kcal |
|
Answer» Correct Answer - D |
|
| 29. |
The rate constant of `n^(th)` order has units :A. `"litre"^(1-n)mol^(1-n)sec^(-1)`B. `"Mol"^(1-n)litre^(1-n)sec`C. `"Mol"^(1-n^(2))litre^(n^(2))sec^(-1)`D. `"Mole"^(1-n)litre^(n-1)sec^(-1)` |
|
Answer» Correct Answer - D |
|
| 30. |
Which of the following processes result in an increase in the atomic number of a nuclide?A. `alpha`-emissionB. electron captureC. `gamma`-emissionD. `beta`-(Beta) emission |
|
Answer» Correct Answer - D |
|
| 31. |
Collision theory is satisfactory for:A. First order reactionsB. Zero order reactionsC. Bimolecular elementary reactionsD. Any order reactions |
|
Answer» Correct Answer - C |
|
| 32. |
Which of the following explains the increase of the reaction rate by catalyst?A. Catalyst decreases the rate of backward reaction so that the rate of forward reaction increasesB. Catalyst provides extra energy to reacting molecules so that they may reduce effective collisionsC. Catalyst provides an alternative path of lower activation energy to the reactants.D. Catalyst increases the number of collisions between the reacting molecules. |
|
Answer» Correct Answer - C |
|
| 33. |
The rate of a reaction gets doubled when temperature increase by `27^(@) C "to" 37^(@)` . By what factor will it change for the temperature range `17^(@)` C to `27^(@)` CA. 1.81B. 1.71C. 2.1D. 2.41 |
|
Answer» Correct Answer - C |
|
| 34. |
The rate constant for a first order reaction whose half life is 480 sec, is :A. `1.44xx10^(-3)sec^(-1)`B. `1.44xxsec^(-1)`C. `0.72xx10^(-3)sec^(-1)`D. `2.88xx10^(-3)sec^(-1)` |
|
Answer» Correct Answer - A |
|
| 35. |
During `alpha`-decay:A. `(n)/(p)` ratio decreasesB. `(n)/(p)` ratio increasesC. `(n)/(p)` ratio remains emission constantD. `(n)/(p)` ratio may increase or decrease |
|
Answer» Correct Answer - B |
|
| 36. |
Consider the following decay `._(Z)^(A)Xrarr_(Z-1)^(A)Y+_(+1)^(0)e,(beta^(+))X` is unstable because:A. its nucleus has excess energyB. `(n)/(p)` ratio is highC. `(n)/(p)` ratio is lowD. none of these |
|
Answer» Correct Answer - C |
|
| 37. |
Consider the following decay `._(Z)^(A)Xrarr_(Z+1)^(A)Y+_(-1)^(0)e,X` is unstable because:A. its nucleus has excess energyB. `(n)/(p)` ratio is highC. `(n)/(p)` ratio is lowD. none of these |
|
Answer» Correct Answer - B |
|
| 38. |
Half-life (`t_(1//2)`) and completion time (T) of the above reaction (`Ato2B`) are :A. 500 min, 750 minB. 500 sec, 750 secC. 50 sec, 100 secD. None of these |
|
Answer» Correct Answer - C |
|
| 39. |
In the series reaction `Aoverset(K_(2))(rarr)Boverset(K_(2))(rarr)Coverset(K_(2))(rarr)D` , if `K_(1)gtK_(2)gtK_(3)` then the rate determing step of the reaction isA. `ArarrB`B. `CrarrD`C. `BrarrC`D. Any step |
|
Answer» Correct Answer - B |
|
| 40. |
Two consecutive irreversible fierst order reactions can be represented by `Aoverset(k_(1))(rarr)Boverset(k_(2))(rarr)C` The rate equation for A is readily interated to obtain `[A]_(t)=[A]_(0).e^(-k_(1^(t)))` , and `[B]_(t)=(k_(1)[A]_(0))/(k_(2)-k_(1))[e^(-k_(1)^(t))-e^(-k_(2)^(t))]` If `k_(1)` and `k_(2)` both are almost same then which graph is most suitable ?A. graph AB. graph BC. graph CD. graph D |
|
Answer» Correct Answer - A |
|
| 41. |
Two consecutive irreversible fierst order reactions can be represented by `Aoverset(k_(1))(rarr)Boverset(k_(2))(rarr)C` The rate equation for A is readily interated to obtain `[A]_(t)=[A]_(0).e^(-k_(1^(t)))` , and `[B]_(t)=(k_(1)[A]_(0))/(k_(2)-k_(1))[e^(-k_(1)^(t))-e^(-k_(2)^(t))]` When `k_(1)=1s^(-1)` and `k_(2)=500s^(-1)` , select most appropriate graphA. B. C. D. |
|
Answer» Correct Answer - B |
|
| 42. |
Which of the following represent the expression for `(3)/(4)`th life of first order reactionA. `(k)/(2.303)log4//3`B. `(2.303)/(k)log3//4`C. `(2.303)/(k)log4`D. `(2.303)/(k)log3` |
|
Answer» Correct Answer - C |
|
| 43. |
The kinetic date for the given reaction `A(g)+2B(g)overset(K)toC(g)` is provided in the following table for three experiments at 300 K `{:("Ex. No.","[A/M]","[B/M]","Initial rate" (M sec^(-1))),(1.,0.01,0.01,6.930xx10^(-6)),(2.,0.02,0.01,1.386xx10^(-5)),(3.,0.2,0.02,1.386xx10^(-5)):} ltbgt In another experiment starting swith initial concentration of `0.5` and 1 M respectively for A and B at 300 K, find the rate of reaction after 50 minutes from the starting of edperiment (inM`//`sec).A. `6.93xx10^(-4)`B. `0.25xx10^(-7)`C. `4.33xx10^(-5)`D. `3.46xx10^(-4)` |
|
Answer» Correct Answer - C |
|
| 44. |
………. Is produced when a positron and an electron collide.A. X-rayB. NeutronC. `gamma`-radiationD. Neutrino |
|
Answer» Correct Answer - C |
|
| 45. |
In the presence of acid, the initial concentration, of cane sugar was reduced form `0.2 M` to `0.1` in `5 hr` and to `0.05 M` in `10 hr`. The reaction must be ofA. Zero orderB. First orderC. Second orderD. Third order |
|
Answer» Correct Answer - B |
|
| 46. |
When ethyl acetate was was hydrolysedin presemce of 0.1 M HCl, the rate constant was found to be `5.4xx10^(-5)s^(-1)`. But in presence of 0.1 M `H_(2)SO_(4)` the rate constant was found to be `6.25xx10^(-5)s^(-1)`. Thus it may be concluded that:A. `H_(2)SO_(4)` furnishes more `H^(+)` than HClB. `H_(2)SO_(4)` furnishes less `H^(+)` than HClC. both have the same strengthD. will depend on concentration of ethyl acetate |
|
Answer» Correct Answer - A |
|
| 47. |
Consider the reaction. The rate constant for two parallel reactions were found to be `10^(-2) dm^(-2)mol^(-1)s^(-1)` and `4xx10^(-2)dm^(-3)mol^(-1)s^(-1)` . If the corresponding energies of activation of the parallel reaction are 100 and 120 kJ/mol respectively, what is the net energy of activation `(E_(a))` of AA. 100 kJ/molB. 120 kJ/molC. 116 kJ/molD. 220 kJ/mol |
|
Answer» Correct Answer - C |
|
| 48. |
A hydrogenation reaction is carried out at `500 K`. If the same reaction is carried out in the presence of a catalyst at the same rate, the temperature required is `400 K`. Calculate the activation energy of the reaction if the catalyst lowers the activation barrier by `20 kJ mol^(-1)`.A. 100 kJ/molB. 80 kJ/molC. 60 kJ/molD. none of these |
|
Answer» Correct Answer - B |
|
| 49. |
Complete the following nuclear equation by suppling the symbol for the other product of the fission : `._(92)^(235)U+_(0)^(1)n rarr _(38)^(94)Sr +………+2_(0)^(1)n`A. `._(54)^(139)Xe`B. `._(54)^(140)Xe`C. `._(64)^(104)Gd`D. none of these |
|
Answer» Correct Answer - B |
|
| 50. |
A following mechanism has been proposed for a reaction `2A +B rarr D rarr E` `A+ B rarrC+D `(slow) `A+C rarr E` (fast) The rate law expression for the reaction by RDS methd is:A. `r=k[A]^(2)[B]`B. `r=k[A][B]`C. `r=k[A]^(2)`D. `r=k[A][C]` |
|
Answer» Correct Answer - B |
|