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MCQOPTIONS
This section includes 11242 Mcqs, each offering curated multiple-choice questions to sharpen your Joint Entrance Exam - Main (JEE Main) knowledge and support exam preparation. Choose a topic below to get started.
| 10951. |
Elements with outer electronic configuration \[n{{s}^{2}}n{{p}^{6}}\] are [MP PET/PMT 1998] |
| A. | Alkaline earth metals |
| B. | Transition elements |
| C. | Chalcogenes |
| D. | Noble gases |
| Answer» E. | |
| 10952. |
Which of the following relation is correct with respect to first (I) and second (II) ionization potentials of sodium and magnesium [CPMT 1999] |
| A. | \[{{I}_{Mg}}=I{{I}_{Na}}\] |
| B. | \[{{I}_{Na}}>{{I}_{Mg}}\] |
| C. | \[I{{I}_{Mg}}>I{{I}_{Na}}\] |
| D. | \[I{{I}_{Na}}>I{{I}_{Mg}}\] |
| Answer» E. | |
| 10953. |
Ionisation energy in group I-A varies in the decreasing order as [Orissa JEE 2005] |
| A. | \[Li>Na>K>Cs\] |
| B. | \[Na>Li>K>Cs\] |
| C. | \[Li>Cs>K>Na\] |
| D. | \[K>Cs>Na>Li\] |
| Answer» B. \[Na>Li>K>Cs\] | |
| 10954. |
Of the following iso-electronic ions, the one which has the lowest ionisation potential is [AMU 1999] |
| A. | \[N{{a}^{+}}\] |
| B. | \[M{{g}^{++}}\] |
| C. | \[{{F}^{-}}\] |
| D. | \[{{O}^{--}}\] |
| Answer» B. \[M{{g}^{++}}\] | |
| 10955. |
Which of these is not used as a fuel in the rocket propellants |
| A. | Liquid He |
| B. | Liquid hydrogen |
| C. | Kerosene |
| D. | Liquid hydrazine |
| Answer» D. Liquid hydrazine | |
| 10956. |
Which of the following could act as a propellant for rocket [CBSE PMT 2003] |
| A. | Liquid hydrogen + Liquid nitrogen |
| B. | Liquid oxygen + Liquid argon |
| C. | Liquid hydrogen + Liquid oxygen |
| D. | Liquid nitrogen + Liquid oxygen |
| Answer» D. Liquid nitrogen + Liquid oxygen | |
| 10957. |
Which is the relation between the specific \[{{I}_{s}}\] impulse and the critical temperature \[{{T}_{c}}\]attained in a rocket blast |
| A. | \[{{I}_{s}}\ge {{T}_{c}}\] |
| B. | \[{{I}_{s}}\] and \[T_{c}^{2}\] |
| C. | \[{{I}_{s}}\ge T_{c}^{1/2}\] |
| D. | \[{{I}_{s}}\ge 1/{{T}_{c}}\] |
| Answer» D. \[{{I}_{s}}\ge 1/{{T}_{c}}\] | |
| 10958. |
A substance which can act both as an analgesic and antipyretic is |
| A. | Quinine |
| B. | Aspirin |
| C. | Penicillin |
| D. | Insulin |
| Answer» C. Penicillin | |
| 10959. |
Which of the following is an anionic detergent? |
| A. | Glyceryl oleate |
| B. | Sodium stearate |
| C. | Sodium lauryl sulphate |
| D. | Cetyltrimethyl ammonium bromide |
| Answer» D. Cetyltrimethyl ammonium bromide | |
| 10960. |
Antiseptics and disinfectants either kill or prevent growth of microorganism. Identify which of the following statements is not true? |
| A. | Chlorine and iodine are used as strong disinfectants |
| B. | Dilute solutions of boric acid and hydrogen, peroxide are strong antiseptics |
| C. | Disinfectants harm the living tissues |
| D. | A 0.2% solution of phenol is an antiseptic while 1% solution acts as a disinfectant. |
| Answer» C. Disinfectants harm the living tissues | |
| 10961. |
The following compound is used as a/an |
| A. | anti-inflammatory compound |
| B. | analgesic |
| C. | hypnotic |
| D. | antiseptic. |
| Answer» C. hypnotic | |
| 10962. |
Which of the following represents soap [DCE 2004] |
| A. | \[{{C}_{17}}{{H}_{35}}COOK\] |
| B. | \[{{C}_{17}}{{H}_{35}}COOH\] |
| C. | \[{{C}_{15}}{{H}_{31}}COOH\] |
| D. | \[{{({{C}_{17}}{{H}_{35}}COO)}_{2}}Ca\] |
| Answer» B. \[{{C}_{17}}{{H}_{35}}COOH\] | |
| 10963. |
Which of the following is an azo dye [Delhi CEE 1996] |
| A. | Orange-I |
| B. | Phenolphthalein |
| C. | Malachite green |
| D. | Methylene blue |
| Answer» B. Phenolphthalein | |
| 10964. |
A reactant [a] forms two products \[A\xrightarrow{{{k}_{1}}}B\] Activation energy \[{{E}_{{{a}_{1}}}}\] \[A\xrightarrow{{{k}_{2}}}C\] Activation energy \[E{{\,}_{{{a}_{2}}}}\] If \[{{E}_{{{a}_{2}}}}=2{{E}_{{{a}_{1}}}},\] then \[{{k}_{1}}\] and \[{{k}_{2}}\] will be related as |
| A. | \[{{k}_{2}}={{k}_{1}}{{e}^{-{{E}_{{{a}_{1}}}}/RT}}\] |
| B. | \[{{k}_{2}}={{k}_{1}}{{e}^{-{{E}_{{{a}_{2}}}}/RT}}\] |
| C. | \[{{k}_{1}}={{k}_{2}}{{e}^{-{{E}_{{{a}_{1}}}}/RT}}\] |
| D. | \[{{k}_{1}}=2{{k}_{2}}{{e}^{{{E}_{{{a}_{2}}}}/RT}}\] |
| Answer» B. \[{{k}_{2}}={{k}_{1}}{{e}^{-{{E}_{{{a}_{2}}}}/RT}}\] | |
| 10965. |
In a gaseous phase reaction,\[{{A}_{2}}(g)\,\xrightarrow{\,}\,B(g)\,+\frac{1}{2}\,(g),\]the increase in pressure from 100 mm to 120 mm is noticed in 5 min. The rate of disappearance of \[{{A}_{2}}\] in mm \[{{\min }^{-1}}\] is |
| A. | 4 |
| B. | 8 |
| C. | 16 |
| D. | 2 |
| Answer» C. 16 | |
| 10966. |
Figure shows a graph in \[{{\log }_{10}}\,k\,vs\,\frac{1}{T}\] where, k is rate constant and T is temperature. The straight line BC has slope, \[\tan \,\theta \,=-\frac{1}{2.303}\] and an intercept of 5 on y-axis. Thus, \[{{E}_{a}},\] the energy of activation, is |
| A. | 4.606 cal |
| B. | \[\frac{0.2}{2.303}cal\] |
| C. | 2 cal |
| D. | None of these |
| Answer» D. None of these | |
| 10967. |
In a reaction involving one single reactant, the fraction of the reactant consumed may be defined as \[f=\left[ 1-\left( C/{{C}_{0}} \right) \right],\] where \[{{C}_{0}}\] and C are the concentrations of the reactant at the start and after time t. For a first-order reaction: |
| A. | \[\frac{df}{dt}=k\left( 1-f \right)\] |
| B. | \[-\frac{df}{dt}=kf\] |
| C. | \[-\frac{df}{dt}=k\left( 1-f \right)\] |
| D. | \[\frac{df}{dt}=kf\] |
| Answer» B. \[-\frac{df}{dt}=kf\] | |
| 10968. |
The forward rate constant for the reversible gaseous reaction \[{{C}_{2}}{{H}_{6}}2C{{H}_{3}}\] is\[3.14\times {{10}^{+2}}{{s}^{-1}}\] at 200 K. What is the rate constant for the backward reaction at this temperature, if \[{{10}^{-5}}\] moles of \[C{{H}_{3}}\] and 100 mol of \[{{C}_{2}}{{H}_{6}}\] are present in 10 L vessel at equilibrium? |
| A. | \[1.57\times {{10}^{14}}Lmo{{l}^{-1}}{{s}^{-1}}\] |
| B. | \[3.14\times {{10}^{15}}Lmo{{l}^{-1}}{{s}^{-1}}\] |
| C. | \[1.57\times {{10}^{7}}Lmo{{l}^{-1}}{{s}^{-1}}\] |
| D. | \[3.14\times {{10}^{10}}Lmo{{l}^{-1}}{{s}^{-1}}\] |
| Answer» C. \[1.57\times {{10}^{7}}Lmo{{l}^{-1}}{{s}^{-1}}\] | |
| 10969. |
Consider the following case of completing 1st order reactions. After the start of the reaction at t = 0 with only A, the [C] is equal to the [D] at all times. The time in which all three concentrations will be equal is given by - |
| A. | \[t=\frac{1}{2{{k}_{1}}}\ell n3\] |
| B. | \[t=\frac{1}{2{{k}_{2}}}\ell n\,3\] |
| C. | \[t=\frac{1}{3{{k}_{1}}}\ell n2\] |
| D. | \[t=\frac{1}{3{{k}_{1}}}\ell n2\] |
| Answer» C. \[t=\frac{1}{3{{k}_{1}}}\ell n2\] | |
| 10970. |
A graph of volume of hydrogen released vs time for the reaction between zinc and dil. HCl is given in figure. On the basis of this mark the correct option. |
| A. | Average rate upto 40s is \[\frac{{{V}_{3}}-{{V}_{2}}}{40}\] |
| B. | Average rate upto 40 seconds is \[\frac{{{V}_{3}}-{{V}_{2}}}{40-30}\] |
| C. | Average rate upto 40 seconds is \[\frac{{{V}_{3}}}{40}\] |
| D. | Average rate upto 40 seconds is \[\frac{{{V}_{3}}-{{V}_{1}}}{40-20}\] |
| Answer» D. Average rate upto 40 seconds is \[\frac{{{V}_{3}}-{{V}_{1}}}{40-20}\] | |
| 10971. |
In a first-order reaction, the reacting substance has half-life period of 10 min. What fraction of the substance will be left after an hour the reaction has occurred? |
| A. | 1/6 of initial concentration |
| B. | 1/64 of initial concentration |
| C. | 1/12 of initial concentration |
| D. | 1/32 of initial concentration |
| Answer» C. 1/12 of initial concentration | |
| 10972. |
A gaseous compound A reacts by three independent first-order processes (as shown in the figure) with rate constants \[2\times {{10}^{-3}},\,3\times {{10}^{-3}}\] and \[1.93\times {{10}^{-3}}{{s}^{-1}}\] products B, C and D respectively. If initially pure A was taken in a closed container with P = 8 atm, then the partial pressure of B (in atm) after 100 s from start of experiment will be: |
| A. | 0.288 |
| B. | 0.577 |
| C. | 1.154 |
| D. | None of these |
| Answer» D. None of these | |
| 10973. |
A hypothetical reaction: \[{{A}_{2}}+{{B}_{2}}\xrightarrow{{}}2AB\] follows mechanism as given below: \[{{A}_{2}}A+A\]............ (fast) (\[{{k}_{c}}\] is equilibrium constant) \[{{A}_{2}}+{{B}_{2}}\xrightarrow{{{k}_{1}}}AB+B\] ..............(slow) (\[{{k}_{1}}\] rate constant) \[A+BAB\] .................. (fast) (\[{{k}_{2}},{{k}_{3}}\] are rate constant) Give the rate law. |
| A. | \[r={{k}_{1}}\sqrt{{{k}_{c}}}\,{{[{{A}_{2}}]}^{1/2}}[{{B}_{2}}]\] |
| B. | \[r=\frac{{{k}_{1}}}{{{k}_{c}}}\,{{[{{A}_{2}}]}^{1/2}}[{{B}_{2}}]\] |
| C. | \[r=\sqrt{{{k}_{1}}{{k}_{c}}}\,\,{{[{{A}_{2}}]}^{1/2}}[{{B}_{2}}]\] |
| D. | \[r=\frac{{{k}_{1}}}{\sqrt{{{k}_{c}}}}\,{{[{{A}_{2}}]}^{1/2}}[{{B}_{2}}]\] |
| Answer» B. \[r=\frac{{{k}_{1}}}{{{k}_{c}}}\,{{[{{A}_{2}}]}^{1/2}}[{{B}_{2}}]\] | |
| 10974. |
In a certain reaction, 10% of the reactant decomposes in 1 h, 20% in 2 h, 30% in 3 h, and so on. The dimensions of the rate constant is: |
| A. | \[{{h}^{-1}}\] |
| B. | \[mol/\left( L\,s \right)\] |
| C. | L / (mol s) |
| D. | mol/s |
| Answer» C. L / (mol s) | |
| 10975. |
The main function of a catalyst in speeding up a reaction is |
| A. | To increase the rate of the forward reaction |
| B. | To change the reaction path so as to decrease the energy of activation for the reaction |
| C. | To reduce the temperature at which the reaction can occur |
| D. | To increase the energy of the molecules of the reactants |
| Answer» C. To reduce the temperature at which the reaction can occur | |
| 10976. |
For the reaction \[X+Y\to Z,\] following kinetic data was obtained : Initial [X]M Initial [Y]M Initial rate M \[\mathbf{mi}{{\mathbf{n}}^{\mathbf{-1}}}\] 0.4 2.0 \[6.2\times {{10}^{-3}}\] 0.8 2.0 \[2.48\times {{10}^{-2}}\] 0.4 4.0 \[1.24\times {{10}^{-2}}\] 0.5 1.5 ? Calculate initial rate in the last experiment |
| A. | \[\text{4}.\text{36}\times \text{l}{{0}^{-\text{3}}}\] |
| B. | \[\text{5}.\text{81}\times \text{l}{{0}^{-\text{3}}}\] |
| C. | \[\text{7}.\text{27}\times \text{l}{{0}^{-\text{3}}}\] |
| D. | \[\text{9}.\text{69}\times \text{l}{{0}^{-\text{3}}}\] |
| Answer» D. \[\text{9}.\text{69}\times \text{l}{{0}^{-\text{3}}}\] | |
| 10977. |
A reaction that is of the first order with respect to reactant A has a rate constant \[6{{\min }^{-1}}\]. If we start with [A]\[0.5\,mol\,{{l}^{-1}},\] when would [A] reach the value \[0.05\,mol\,{{l}^{-1}}\] |
| A. | 0.384 min |
| B. | 0.15 min |
| C. | 3 min |
| D. | 3.84 min |
| Answer» B. 0.15 min | |
| 10978. |
Which of the following statements regarding the molecularity of a reaction are correct? |
| A. | It is the number of molecules of the reactants taking part in a single step chemical reaction |
| B. | It is calculated from reaction mechanism |
| C. | It depends on the rate determining step in the reaction |
| D. | It always whole number. |
| Answer» B. It is calculated from reaction mechanism | |
| 10979. |
\[A\to B;\,\,\,\,\,\,\,\,\,\,\,\,\,{{k}_{A}}={{10}^{15}}{{e}^{-2000/T}}\] \[C\to D;\,\,\,\,\,\,\,\,\,\,\,\,\,{{k}_{C}}={{10}^{14}}{{e}^{-1000/T}}\] Temperature T kelvin at which \[(\,{{k}_{A}}={{k}_{C}})\] is: |
| A. | 1000 K |
| B. | 2000 K |
| C. | (2000/2.303) K |
| D. | (1000/2.303) K |
| Answer» E. | |
| 10980. |
The reaction cis\[-X\text{trans}-X\] is first order in both directions. At \[\text{25}{}^\circ \text{C,}\] the equilibrium constant is 0.10 and the rate constant \[{{k}_{f}}=3\times {{10}^{-4}}{{s}^{-1}}\]. In an experiment starting with the pure cis-form, how long would it take for half of the equilibrium amount of the trans-isomer to be formed? |
| A. | 150 s |
| B. | 200 s |
| C. | 240 s |
| D. | 210 s |
| Answer» E. | |
| 10981. |
\[(aq)\xrightarrow{{}}B(aq)+C(aq)\] is a first order reaction. Time t \[\infty \] Moles of reagent \[{{x}_{1}}\] \[{{x}_{2}}\] Reaction progress is measured with the help of titration of reagent P, if all A, B and C reacted with reagent have n factors \[\left[ \text{n factor}:n=\frac{mol.wt.}{eq.wt.} \right]\] in the ratio 1 : 2 : 3 with the reagent. The k in terms of t, \[{{x}_{1}}\] and \[{{x}_{2}}\] is |
| A. | \[k=\frac{1}{t}\ln \left( \frac{{{x}_{2}}}{{{x}_{2}}-{{x}_{1}}} \right)\] |
| B. | \[k=\frac{1}{t}\ln \left( \frac{2{{x}_{2}}}{{{x}_{2}}-{{x}_{1}}} \right)\] |
| C. | \[k=\frac{1}{t}\ln \left( \frac{4{{x}_{2}}}{5({{x}_{2}}-{{x}_{1}})} \right)\] |
| D. | \[k=\frac{1}{t}\ln \left( \frac{8{{x}_{2}}}{{{x}_{2}}-{{x}_{1}}} \right)\] |
| Answer» D. \[k=\frac{1}{t}\ln \left( \frac{8{{x}_{2}}}{{{x}_{2}}-{{x}_{1}}} \right)\] | |
| 10982. |
A reaction is catalysed by ?X ?. Here ?X ? [MP PMT 2003] |
| A. | Decreases the rate constant of reaction |
| B. | Does not affect the equilibrium constant of reaction |
| C. | Decreases the enthalpy of reaction |
| D. | Decreases the activation energy |
| Answer» E. | |
| 10983. |
Velocity constant of a reaction at 290 K was found to be\[3.2\times {{10}^{-3}}\]. At 310 K it will be about [KCET 1989, 91] |
| A. | \[1.28\times {{10}^{-2}}\] |
| B. | \[9.6\times {{10}^{-3}}\] |
| C. | \[6.4\times {{10}^{-3}}\] |
| D. | \[3.2\times {{10}^{-4}}\] |
| Answer» B. \[9.6\times {{10}^{-3}}\] | |
| 10984. |
The rate at which a substance reacts depends on its [MP PMT 1987; BHU 1999; KCET 2005] |
| A. | Atomic weight |
| B. | Equivalent weight |
| C. | Molecular weight |
| D. | Active mass |
| Answer» E. | |
| 10985. |
An increase in temperature by \[{{10}^{o}}C\], generally increases the rate of a reaction by |
| A. | 2 times |
| B. | 10 times |
| C. | 9 times |
| D. | 100 times |
| Answer» B. 10 times | |
| 10986. |
The rate of a gaseous reaction is given by the expression \[K\,[A]\,[B]\]. If the volume of the reaction vessel is suddenly reduced to 1/4th of the initial volume, the reaction rate relating to original rate will be [Roorkee 1992] |
| A. | 1/10 |
| B. | 1/8 |
| C. | 8 |
| D. | 16 |
| Answer» E. | |
| 10987. |
The rate of a reaction depends upon the [Pb. PMT 1999] |
| A. | Volume |
| B. | Force |
| C. | Pressure |
| D. | Concentration of reactant |
| Answer» E. | |
| 10988. |
The thermal decomposition of a compound is of first order. If a sample of the compound decomposes 50% in 120 minutes, in what time will it undergo 90% decomposition [MP PET 1996] |
| A. | Nearly 240 minutes |
| B. | Nearly 480 minutes |
| C. | Nearly 450 minutes |
| D. | Nearly 400 minutes |
| Answer» E. | |
| 10989. |
The half life for the reaction \[{{N}_{2}}{{O}_{5}}\]⇌ \[2N{{O}_{2}}+\frac{1}{2}{{O}_{2}}\] in \[24\,hrs\] at \[{{30}^{o}}C\]. Starting with \[10\,g\] of \[{{N}_{2}}{{O}_{5}}\] how many grams of \[{{N}_{2}}{{O}_{5}}\] will remain after a period of 96 hours [KCET 1992] |
| A. | \[1.25\,g\] |
| B. | \[0.63\,g\] |
| C. | \[1.77\,g\] |
| D. | \[0.5\,g\] |
| Answer» C. \[1.77\,g\] | |
| 10990. |
Diazonium salt decomposes as \[{{C}_{6}}{{H}_{5}}N_{2}^{+}C{{l}^{-}}\to {{C}_{6}}{{H}_{5}}Cl+{{N}_{2}}\] At \[{{0}^{o}}C\], the evolution of \[{{N}_{2}}\] becomes two times faster when the initial concentration of the salt is doubled. Therefore, it is [MNR 1994; UPSEAT 2002] |
| A. | A first order reaction |
| B. | A second order reaction |
| C. | Independent of the initial concentration of the salt |
| D. | A zero order reaction |
| Answer» B. A second order reaction | |
| 10991. |
For the reaction \[2HI\]⇌\[{{H}_{2}}+{{I}_{2}}\], the rate of the reaction is proportional to \[{{[HI]}^{2}}\]. This means that the reaction is [AMU 1985; MP PET 2000] |
| A. | Unimolecular |
| B. | Bimolecular |
| C. | Of first order |
| D. | Of second order |
| Answer» E. | |
| 10992. |
Value of velocity constant for first order reaction is \[3.46\times {{10}^{-3}}{{\min }^{-1}}\], the time for half change is |
| A. | 100 minutes |
| B. | 400 minutes |
| C. | 200 minutes |
| D. | 346 minutes |
| Answer» D. 346 minutes | |
| 10993. |
An example of a pseudo ?unimolecular reaction is |
| A. | Dissociation of hydrogen iodide |
| B. | Hydrolysis of methyl acetate in dilute solution |
| C. | Dissociation of phosphorus pentachloride |
| D. | Decomposition of hydrogen peroxide |
| Answer» C. Dissociation of phosphorus pentachloride | |
| 10994. |
In presence of \[HCl\], sucrose gets hydrolysed into glucose and fructose. The concentration of sucrose was found to reduce form 0.4 M to 0.2 M in 1 hour and 0.1 M in 2 hours. The order of the reaction is |
| A. | Zero |
| B. | One |
| C. | Two |
| D. | None of these |
| Answer» C. Two | |
| 10995. |
Which one of the following statements is wrong |
| A. | Molecularity of a reaction is always a whole number |
| B. | Order and molecularity of a reaction need not be same |
| C. | Order of a reaction may be zero |
| D. | Order of a reaction depends upon the mechanism of the reaction |
| Answer» E. | |
| 10996. |
The decomposition of \[{{N}_{2}}{{O}_{5}}\] is a first order reaction represented by \[{{N}_{2}}{{O}_{5}}\to {{N}_{2}}{{O}_{4}}+\frac{1}{2}{{O}_{2}}\]. After 15 minutes the volume of \[{{O}_{2}}\] produced is \[9\,ml\] and at the end of the reaction \[35\,ml\]. The rate constant is equal to [MP PET 1995] |
| A. | \[\frac{1}{15}\,\ln \,\frac{35}{44}\] |
| B. | \[\frac{1}{15}\,\ln \,\frac{44}{26}\] |
| C. | \[\frac{1}{15}\,\ln \,\frac{44}{35}\] |
| D. | \[\frac{1}{15}\,\ln \,\frac{35}{26}\] |
| Answer» E. | |
| 10997. |
The hydrolysis of ethyl acetate is a reaction of [MP PMT 1987] \[C{{H}_{3}}COOEt+{{H}_{2}}O\xrightarrow{{{H}^{+}}}C{{H}_{3}}COOH+EtOH\] |
| A. | First order |
| B. | Second order |
| C. | Third order |
| D. | Zero order |
| Answer» B. Second order | |
| 10998. |
The rate constant of a reaction depends upon [BHU 2004] |
| A. | Extent of reaction |
| B. | Time of reaction |
| C. | Temperature of the system |
| D. | Concentration of the system |
| Answer» D. Concentration of the system | |
| 10999. |
The half-life of a first order reaction having rate constant K = 1.7 ´ 10-5 s-1 is [BHU 2005] |
| A. | 12.1 h |
| B. | 9.7 h |
| C. | 11.3 h |
| D. | 1.8 h |
| Answer» D. 1.8 h | |
| 11000. |
The velocity constant of a reaction is K. Which of the following statements is not true regarding K |
| A. | K is a constant for a reaction at a given temperature |
| B. | The value of K changes when the temperature changes |
| C. | K is the velocity of the reaction at unit concentrations of the reactant |
| D. | K is a constant for all reactions |
| Answer» E. | |