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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.
| 451. |
The in \[{{\Delta }_{f}}H{}^\circ ({{N}_{2}}{{O}_{5}},g)\] kJ/mol on the basis of the following data is -\[2NO(g)+{{O}_{2}}(g)\to 2N{{O}_{2}}(g);\]\[{{\Delta }_{r}}H{}^\circ =-114\,kJ/mol\]\[4N{{O}_{2}}(g)+{{O}_{2}}(g)\to 2{{N}_{2}}{{O}_{5}}(g);\]\[{{\Delta }_{r}}H{}^\circ =-102.6\,kJ/mol\]\[{{\Delta }_{f}}H{}^\circ (NO,g)=90.2kJ/mol\] |
| A. | 15.1 |
| B. | 30.2 |
| C. | -36.2 |
| D. | None of these |
| Answer» B. 30.2 | |
| 452. |
Which of the following is the correct order of gradually decreasing basic nature of the oxides [MP PMT 1997] |
| A. | \[A{{l}_{2}}{{O}_{3}}\], \[MgO\], \[C{{l}_{2}}{{O}_{7}}\], \[S{{O}_{3}}\] |
| B. | \[MgO\], \[A{{l}_{2}}{{O}_{3}}\], \[S{{O}_{3}}\], \[C{{l}_{2}}{{O}_{7}}\] |
| C. | \[C{{l}_{2}}{{O}_{7}}\], \[S{{O}_{3}}\], \[A{{l}_{2}}{{O}_{3}}\], \[MgO\] |
| D. | \[S{{O}_{3}}\], \[C{{l}_{2}}{{O}_{7}}\], \[MgO\], \[A{{l}_{2}}{{O}_{3}}\] |
| Answer» C. \[C{{l}_{2}}{{O}_{7}}\], \[S{{O}_{3}}\], \[A{{l}_{2}}{{O}_{3}}\], \[MgO\] | |
| 453. |
All element in 3rd period have [JIPMER 1997] |
| A. | An atomic number 3 |
| B. | 3 complete sub-shells |
| C. | Valence electrons shell |
| D. | 3 electrons less than the octet |
| Answer» D. 3 electrons less than the octet | |
| 454. |
Which shows variable valency [RPMT 1997] |
| A. | s - block elements |
| B. | p - block elements |
| C. | d - block elements |
| D. | Radioactive elements |
| Answer» D. Radioactive elements | |
| 455. |
Most reducing agent is [UPSEAT 1999] |
| A. | K |
| B. | Mg |
| C. | Al |
| D. | Ba |
| Answer» B. Mg | |
| 456. |
How many ml of 1 (M) \[{{H}_{2}}S{{O}_{4}}\] is required to neutralise 10 ml of 1(M) \[NaOH\] solution [MP PET 1997; MP PMT 1999] |
| A. | 2.5 |
| B. | 5 |
| C. | 10 |
| D. | 20 |
| Answer» C. 10 | |
| 457. |
Carbohydrates are [MADT Bihar 1983] |
| A. | Hydrates of carbon |
| B. | Polyhydroxy aldehydes or ketones |
| C. | Polyhydroxy acid compounds |
| D. | None of these |
| Answer» C. Polyhydroxy acid compounds | |
| 458. |
If W is atomic weight and N is the atomic number of an element, then [CPMT 1971, 80, 89] |
| A. | Number of \[{{e}^{-1}}=W-N\] |
| B. | Number of \[_{0}{{n}^{1}}=W-N\] |
| C. | Number of \[_{1}{{H}^{1}}=W-N\] |
| D. | Number of \[_{0}{{n}^{1}}=N\] |
| Answer» C. Number of \[_{1}{{H}^{1}}=W-N\] | |
| 459. |
The formation of a chemical bond is accompanied by [MP PET 1995] |
| A. | Decrease in energy |
| B. | Increase in energy |
| C. | Neither increase nor decrease in energy |
| D. | None of these |
| Answer» B. Increase in energy | |
| 460. |
Silicon is [MHCET 2004] |
| A. | Semiconductor |
| B. | Insulator |
| C. | Conductor |
| D. | None of these |
| Answer» B. Insulator | |
| 461. |
Which one of the following in used to make 'non-stick' cookware [CBSE PMT 1997; AIIMS 1998] |
| A. | PVC |
| B. | Polystyrene |
| C. | Polyethylene terephthalate |
| D. | Polytetrafluoroethylene |
| Answer» E. | |
| 462. |
Only two isomers of monochloro product is possible of [IIT-JEE 1986] |
| A. | n-butane |
| B. | 2,4-dimethyl pentane |
| C. | Benzene |
| D. | 1-methyl propane |
| Answer» B. 2,4-dimethyl pentane | |
| 463. |
Change of hydrogen into proton is: |
| A. | Reduction of hydrogen |
| B. | Oxidation of Hydrogen |
| C. | Acid-base reaction |
| D. | Displacement reaction |
| Answer» C. Acid-base reaction | |
| 464. |
Meso-tartaric acid is optically inactive due to the presence of [AIIMS 1982; MP PMT 1987] |
| A. | Molecular symmetry |
| B. | Molecular asymmetry |
| C. | External compensation |
| D. | Two asymmetric C-atoms |
| Answer» B. Molecular asymmetry | |
| 465. |
In the following reaction, \[A{{s}_{2}}{{S}_{3}}+{{H}^{+}}+NO_{3}^{-}\xrightarrow{{}}\]\[NO+{{H}_{2}}O+AsO_{4}^{3-}+SO_{4}^{2-},\] the equivalent weight of \[A{{s}_{2}}{{S}_{3}}\] is related to molecular weight by |
| A. | \[\frac{M}{14}\] |
| B. | \[\frac{M}{28}\] |
| C. | \[\frac{M}{7}\] |
| D. | \[\frac{M}{10}\] |
| Answer» C. \[\frac{M}{7}\] | |
| 466. |
The possibility of finding an electron in an orbital was conceived by |
| A. | Rutherford |
| B. | Bohr |
| C. | Heisenberg |
| D. | Schrodinger |
| Answer» E. | |
| 467. |
For an electron if the uncertainty in velocity is \[\Delta \nu \], the uncertainty in its position \[(\Delta x)\] is given by |
| A. | \[\frac{hm}{4\pi \Delta \nu }\] |
| B. | \[\frac{4\pi }{hm\Delta \nu }\] |
| C. | \[\frac{h}{4\pi m\Delta \nu }\] |
| D. | \[\frac{4\pi \ m}{h\ .\ \Delta \nu }\] |
| Answer» D. \[\frac{4\pi \ m}{h\ .\ \Delta \nu }\] | |
| 468. |
In a multi-electron atom, which of the following orbitals described by the three quantum members will have the same energy in the absence of magnetic and electric fields?[A] \[n=1,l=0,m=0\][B] \[n=2,l=0,m=0\] [C] \[n=2,l=1,m=1\][D] \[n=3,l=2,m=1\][E] \[n=3,l=2,m=0\] |
| A. | [D] and [E] |
| B. | [C] and [D] |
| C. | [B] and [C] |
| D. | [A] and [B] |
| Answer» B. [C] and [D] | |
| 469. |
When \[{{H}_{2}}S\]is passed through a mixture containing \[C{{u}^{+2}}\], \[N{{i}^{+2}}\], \[Z{{n}^{+2}}\] in acidic solution then ion will precipitate [RPMT 2002] |
| A. | \[C{{u}^{+2}}\], \[N{{i}^{+2}}\] |
| B. | \[N{{i}^{+2}}\] |
| C. | \[C{{u}^{+2}}\], \[Z{{n}^{+2}}\] |
| D. | \[C{{u}^{+2}}\] |
| Answer» E. | |
| 470. |
\[100c{{m}^{3}}\] of \[0.1N\text{ }HCl\] is mixed with \[100c{{m}^{3}}\] of \[0.2N\text{ }NaOH\] solution. The resulting solution is |
| A. | 0.1 N and the solution is basic |
| B. | 0.1 N and the solution is acidic |
| C. | 0.05 N and the solution is basic |
| D. | 0.05 N and the solution is acidic |
| Answer» D. 0.05 N and the solution is acidic | |
| 471. |
It is known that atoms have proton, neutron, electron and nucleus. If the mass of neutron assumed to be half of its original value whereas that of proton is assumed to be twice the original value, then the atomic mass of \[_{6}{{C}^{14}}\] will be |
| A. | 14.3% less than original value |
| B. | 14.3% greater than original value |
| C. | 28.6% less than original value |
| D. | 28.6% greater than original value |
| Answer» B. 14.3% greater than original value | |
| 472. |
Arrange the following (I to IV) in the order of increasing masses. I. 0.5 mole of \[{{O}_{3}}\] II. \[3.01\times {{10}^{23}}\] molecules of \[{{O}_{2}}\] III. 5.6 L of \[C{{O}_{2}}\] at STP IV. 0.5 g atom of \[{{O}_{2}}\] |
| A. | IV < III < II < I |
| B. | II < I < III < IV |
| C. | II = I < III < IV |
| D. | I < III < IV < II |
| Answer» B. II < I < III < IV | |
| 473. |
One fermi is [Haryana CEET 1994; DPMT 2004] |
| A. | \[{{10}^{-13}}\]cm |
| B. | \[{{10}^{-15}}\]cm |
| C. | \[{{10}^{-10}}\]cm |
| D. | \[{{10}^{-12}}\]cm |
| Answer» B. \[{{10}^{-15}}\]cm | |
| 474. |
The average distance of an electron in an atom from its nucleus is of the order of |
| A. | \[{{10}^{6}}m\] |
| B. | \[{{10}^{-6}}m\] |
| C. | \[{{10}^{-10}}m\] |
| D. | \[{{10}^{-15}}m\] |
| Answer» D. \[{{10}^{-15}}m\] | |
| 475. |
If W is atomic weight and N is the atomic number of an element, then |
| A. | Number of \[{{e}^{-1}}=W-N\] |
| B. | Number of \[_{0}{{n}^{1}}=W-N\] |
| C. | Number of \[_{1}{{H}^{1}}=W-N\] |
| D. | Number of \[_{0}{{n}^{1}}=N\] |
| Answer» C. Number of \[_{1}{{H}^{1}}=W-N\] | |
| 476. |
Positive ions are formed from the neutral atom by the |
| A. | Increase of nuclear charge |
| B. | Gain of protons |
| C. | Loss of electrons |
| D. | Loss of protons |
| Answer» D. Loss of protons | |
| 477. |
The size of nucleus is measured in |
| A. | amu |
| B. | Angstrom |
| C. | Fermi |
| D. | cm |
| Answer» D. cm | |
| 478. |
The molecular weight of hydrogen peroxide is 34. What is the unit of molecular weight [MP PMT 1986] |
| A. | \[g\] |
| B. | \[mol\] |
| C. | \[g\,mo{{l}^{-1}}\] |
| D. | \[mol\,{{g}^{-1}}\] |
| Answer» D. \[mol\,{{g}^{-1}}\] | |
| 479. |
In the redox reaction \[2MnO_{4}^{-}+5{{C}_{2}}O_{4}^{2-}+16{{H}^{+}}\]⇌\[2M{{n}^{2+}}+10C{{O}_{2}}+8{{H}_{2}}O\] The ion acting as autocatalyst is [MP PMT 1986,94] |
| A. | \[MnO_{4}^{-}\] |
| B. | \[{{C}_{2}}O_{4}^{2-}\] |
| C. | \[{{H}^{+}}\] |
| D. | \[M{{n}^{2+}}\] |
| Answer» E. | |
| 480. |
A sample of phosphorus trichloride \[(PC{{l}_{3}})\] contains 1.4 moles of the substance. How many atoms are there in the sample [Kerala PMT 2004] |
| A. | 4 |
| B. | 5.6 |
| C. | \[8.431\times {{10}^{23}}\] |
| D. | \[3.372\times {{10}^{24}}\] |
| E. | \[2.409\times {{10}^{24}}\] |
| Answer» D. \[3.372\times {{10}^{24}}\] | |
| 481. |
The radius of the nucleus is related to the mass number \[A\] by |
| A. | \[R={{R}_{o}}{{A}^{1/2}}\] |
| B. | \[R={{R}_{o}}A\] |
| C. | \[R={{R}_{o}}{{A}^{2}}\] |
| D. | \[R={{R}_{o}}{{A}^{1/3}}\] |
| Answer» E. | |
| 482. |
The mass of a photon with a wavelength equal to \[1.54\times {{10}^{-8}}cm\] is |
| A. | \[0.8268\times {{10}^{-34}}kg\] |
| B. | \[1.2876\times {{10}^{-33}}kg\] |
| C. | \[1.4285\times {{10}^{-32}}kg\] |
| D. | \[1.8884\times {{10}^{-32}}kg\] |
| Answer» D. \[1.8884\times {{10}^{-32}}kg\] | |
| 483. |
The de-Broglie equation applies |
| A. | To electrons only |
| B. | To neutrons only |
| C. | To protons only |
| D. | All the material object in motion |
| Answer» E. | |
| 484. |
Which of the following transitions have minimum wavelength |
| A. | \[{{n}_{4}}\to {{n}_{1}}\] |
| B. | \[{{n}_{2}}\to {{n}_{1}}\] |
| C. | \[{{n}_{4}}\to {{n}_{2}}\] |
| D. | \[{{n}_{3}}\to {{n}_{1}}\] |
| Answer» B. \[{{n}_{2}}\to {{n}_{1}}\] | |
| 485. |
What will be de-Broglie wavelength of an electron moving with a velocity of \[1.2\times {{10}^{5}}\,m{{s}^{-1}}\] |
| A. | \[6.068\times {{10}^{-9}}\] |
| B. | \[3.133\times {{10}^{-37}}\] |
| C. | \[6.626\times {{10}^{-9}}\] |
| D. | \[6.018\times {{10}^{-7}}\] |
| Answer» D. \[6.018\times {{10}^{-7}}\] | |
| 486. |
In Lewis acid-base theory, neutralization reaction may be considered as [NCERT 1977] |
| A. | Formation of salt and water |
| B. | Competition for protons by acid and base |
| C. | Oxidation reduction |
| D. | Coordinate covalent bond formation |
| Answer» E. | |
| 487. |
One mole of fluorine is reacted with two moles of hot and concentrated \[KOH\]. The products formed are \[KF,{{H}_{2}}O\] and\[{{O}_{2}}\] . The molar ratio of \[KF,{{H}_{2}}O\] and \[{{O}_{2}}\] respectively is |
| A. | 1:1:2 |
| B. | 0.0840335648148148 |
| C. | 1:2:1 |
| D. | 0.0840509259259259 |
| Answer» C. 1:2:1 | |
| 488. |
The uncertainty in the position of a moving bullet of mass 10 gm is \[{{10}^{-5}}m\]. Calculate the uncertainty in its velocity [DCE 1999] |
| A. | \[5.2\times {{10}^{-28}}m/sec\] |
| B. | \[3.0\times {{10}^{-28}}m/sec\] |
| C. | \[5.2\times {{10}^{-22}}m/sec\] |
| D. | \[3\times {{10}^{-22}}m/sec\] |
| Answer» B. \[3.0\times {{10}^{-28}}m/sec\] | |
| 489. |
The number of possible isomers of butene are [Kerala (Engg.) 2002] |
| A. | 3 |
| B. | 2 |
| C. | 4 |
| D. | 5 |
| E. | 6 |
| Answer» B. 2 | |
| 490. |
Which indicator can be used in the titration of strong acid and strong base [CBSE PMT 1988] |
| A. | Only phenolphthalein |
| B. | Only methyl orange |
| C. | Either of the two |
| D. | Red litmus |
| Answer» D. Red litmus | |
| 491. |
Alum helps in purifying water by [AIEEE 2002] |
| A. | Forming Si complex with clay particles |
| B. | Sulphate part which combines with the dirt and removes it |
| C. | Aluminium which coagulates the mud particles |
| D. | Making mud water soluble |
| Answer» D. Making mud water soluble | |
| 492. |
The lustre of a metal is due to [AFMC 1998] |
| A. | Its high density |
| B. | Its high polishing |
| C. | Its chemical inertness |
| D. | Presence of free electrons |
| Answer» E. | |
| 493. |
A nucleotide consists of |
| A. | Base and sugar |
| B. | Base and phosphate |
| C. | Sugar and phosphate |
| D. | Base, sugar and phosphate |
| Answer» E. | |
| 494. |
The correct increasing bond angles order is |
| A. | \[B{{F}_{3}}<N{{F}_{3}}<P{{F}_{3}}<Cl{{F}_{3}}\] |
| B. | \[Cl{{F}_{3}}<P{{F}_{3}}<N{{F}_{3}}<B{{F}_{3}}\] |
| C. | \[B{{F}_{3}}=N{{F}_{3}}<P{{F}_{3}}<Cl{{F}_{3}}\] |
| D. | \[B{{F}_{3}}<N{{F}_{3}}<P{{F}_{3}}<Cl{{F}_{3}}\] |
| Answer» C. \[B{{F}_{3}}=N{{F}_{3}}<P{{F}_{3}}<Cl{{F}_{3}}\] | |
| 495. |
Arrange the following in decreasing order of their bond length, \[{{O}_{2}},{{O}_{2}}^{+},{{O}_{2}}^{-}\] and \[O_{2}^{2-}\] |
| A. | \[O_{2}^{2-}<O_{2}^{-}<{{O}_{2}}+O_{2}^{+}\] |
| B. | \[{{O}_{2}}<O_{2}^{2-}<O_{2}^{-}<O_{2}^{+}\] |
| C. | \[O_{2}^{+}<O_{2}^{-}<O_{2}^{2-}<{{O}_{2}}\] |
| D. | \[O_{2}^{+}<{{O}_{2}}<O_{2}^{-}<O_{2}^{2-}\] |
| Answer» E. | |
| 496. |
Glycolysis is [CBSE PMT 2003] |
| A. | Conversion of glucose to haem |
| B. | Oxidation of glucose to glutamate |
| C. | Conversion of pyruvate to citrate |
| D. | Oxidation of glucose to pyruvate |
| Answer» E. | |
| 497. |
Wave function of an orbital is given below in the variation or w.r.t. distance from nucleus. It may the graphical representation of |
| A. | 1s |
| B. | 2s |
| C. | 2p |
| D. | 3s |
| Answer» E. | |
| 498. |
Solid \[C{{O}_{2}}\] is an example of |
| A. | Molecular crystal |
| B. | Ionic crystal |
| C. | Covalent crystal |
| D. | Metallic crystal |
| Answer» B. Ionic crystal | |
| 499. |
An electron in an atom jumps in such a way that its kinetic energy changes from \[x\] to \[x/4\]. The change in potential energy will be: |
| A. | \[+\frac{3}{2}x\] |
| B. | \[-\frac{3}{8}x\] |
| C. | \[+\frac{3}{4}x\] |
| D. | \[-\frac{3}{4}x\] |
| Answer» B. \[-\frac{3}{8}x\] | |
| 500. |
If the diameter of two different nuclei are in the ratio 1 : 3 then their mass number are in the ratio : |
| A. | 0.04375 |
| B. | 1 : 9 |
| C. | 1.12569444444444 |
| D. | 0.0604166666666667 |
| Answer» E. | |