Explore topic-wise MCQs in Joint Entrance Exam - Main (JEE Main).

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.

301.

The isomerism shown by n-butyl alcohol and isobutyl alcohol is [RPMT 2000]

A. Metamerism
B. Chain
C. Position
D. Stereo
Answer» C. Position
302.

Which is optically active [MH CET 2001]

A. \[C{{H}_{2}}C{{l}_{2}}\]
B. \[CHC{{l}_{3}}\]
C. Meso form of tartaric acid
D. Glyceraldehyde
Answer» E.
303.

Volume of \[\frac{N}{10}{{H}_{2}}S{{O}_{4}}\] required to neutralize 10 ml 5 N \[N{{a}_{2}}C{{O}_{3}}\] is

A. 100 ml
B. 50 ml
C. 500 ml
D. 1000 ml
Answer» D. 1000 ml
304.

Which of the following acts as an oxidizing as well as reducing agent?

A. \[N{{a}_{2}}O\]
B. \[N{{a}_{2}}{{O}_{2}}\]
C. \[NaN{{O}_{3}}\]
D. \[NaN{{O}_{2}}\]
Answer» E.
305.

When \[\alpha \]-particles are sent through a thin metal foil, most of them go straight through the foil because (one or more are correct)                                            [IIT 1984]

A. Alpha particles are much heavier than electrons
B. Alpha particles are positively charged
C. Most part of the atom is empty space
D. Alpha particles move with high velocity
Answer» D. Alpha particles move with high velocity
306.

Which has maximum bond angle                              [CPMT 1993]

A. \[CH{{F}_{3}}\]
B. \[CHC{{l}_{3}}\]
C. \[CHB{{r}_{3}}\]
D. All have maximum bond angle
Answer» B. \[CHC{{l}_{3}}\]
307.

Mohr's salt is a                                  [MNR 1986]

A. Normal salt
B. Acid salt
C. Basic salt
D. Double salt
Answer» E.
308.

The number of hydroxide ions, produced by one molecule of sodium carbonate \[(N{{a}_{2}}C{{O}_{3}})\] on hydrolysis is [Pb. CET 2002]

A. 2
B. 1
C. 3
D. 4
Answer» B. 1
309.

Specific volume of cylindrical virus particle is \[6.02\times {{10}^{-2}}cc/g.\] whose radius and length are 7 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] & 10 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] respectively.If \[{{N}_{A}}=6.02\times {{10}^{23}}mo{{l}^{-1}}\] find molecular weight of virus

A. \[3.08\times {{10}^{3}}kg/mol\]
B. \[3.08\times {{10}^{4}}kg/mol\]
C. \[1.54\times {{10}^{4}}kg/mol\]
D. \[15.4kg/mol\]
Answer» E.
310.

Which of the following is soluble in yellow ammonium sulphide [MP PET 1994, 97]

A. \[CuS\]
B. \[CdS\]
C. \[SnS\]
D. \[PbS\]
Answer» D. \[PbS\]
311.

In \[Br{{F}_{3}}\] molecule,the lone pairs occupy equatorial positions to minimize                            [CBSE PMT 2004]

A. Lone pair- lone pair repuilsion and lone pair-bond pair repulsion
B. Lone pair- lone pair repulsion only
C. Lone pair- bond pair repulsion only
D. Bond pair- bond pair repulsion only
Answer» C. Lone pair- bond pair repulsion only
312.

The nuclear binding energy for \[Ar\](39.962384 amu) is: (given mass of proton and neutron are 1.007825 amu and 1.008665 amu respectively)         [Pb.CET 2002]

A. \[343.81\ MeV\]
B. \[0.369096\ MeV\]
C. \[931\ MeV\]
D. None of these
Answer» B. \[0.369096\ MeV\]
313.

Conc. \[HN{{O}_{3}}\] is added before proceeding to test for group III members. This is to [NCERT 1974]

A. Oxidise any remaining \[{{H}_{2}}S\]
B. Convert ferrous ion into ferric ion
C. Form nitrates which give granular ppts
D. Increase ionisation of ammonium hydroxide
Answer» C. Form nitrates which give granular ppts
314.

The sulphate of a metal M contains 9.87% of M. This sulphate is isomorphous with \[ZnS{{O}_{4}}.7{{H}_{2}}O\]. The atomic weight of M is                                                [IIT 1991]

A. 40.3
B. 36.3
C. 24.3
D. 11.3
Answer» D. 11.3
315.

When \[C{{l}_{2}}\] water is added to a salt solution containing chloroform, chloroform layer turns violet. Salt contains [CPMT 1982]

A. \[C{{l}^{-}}\]
B. \[{{I}^{-}}\]
C. \[NO_{3}^{-}\]
D. \[{{S}^{2-}}\]
Answer» C. \[NO_{3}^{-}\]
316.

Amorphous substances show A             Short and long range order B             Short range order C             Long range order D             Have no sharp M.P.

A. A and C are correct
B. B and C are correct
C. C and D are correct
D. B and D are correct
Answer» E.
317.

Which of the following statements is correct for \[CsB{{r}_{3}}\]?

A. It is a covalent compound.
B. It contains \[C{{s}^{3+}}\] and \[B{{r}^{-}}\] ions.
C. It contains \[C{{s}^{+}}\] and \[B{{r}_{3}}^{-}\] ions
D. It contains \[C{{s}^{+}},\] and \[B{{r}^{-}}\] and lattice \[B{{r}_{2}}\] molecule.
Answer» D. It contains \[C{{s}^{+}},\] and \[B{{r}^{-}}\] and lattice \[B{{r}_{2}}\] molecule.
318.

Heavy water \[({{D}_{2}}O)\] is [RPET/PMT 2000; CPMT 2000]

A. A product of oxygen and hydrogen
B. Water of mineral springs
C. Water obtained by repeated distillation and condensation
D. Ordinary water containing dissolved salts heavy metals
Answer» D. Ordinary water containing dissolved salts heavy metals
319.

Temporary hardness may be removed from water by adding [Pb. PMT 2002]

A. \[CaC{{O}_{3}}\]
B. \[Ca{{(OH)}_{2}}\]
C. \[CaS{{O}_{4}}\]
D. HCl
Answer» C. \[CaS{{O}_{4}}\]
320.

In presence of catalyst, the activation energy is lowered by 3 kcal at \[27{}^\circ C\]. Hence, the rate of reaction will increase by

A. 32 times
B. 243 times
C. 2 times
D. 148 times
Answer» E.
321.

Which is used as an antifreeze   [AFMC 1992]

A. Glycol
B. Ethyl alcohol
C. Water
D. Methanol
Answer» B. Ethyl alcohol
322.

Given the numbers : 161cm, 0.161cm, 0.0161 cm. The number of significant figures for the three numbers are [CBSE PMT 1998]

A. 3, 4 and 5 respectively
B. 3, 3 and 3 respectively
C. 3, 3 and 4 respectively
D. 3, 4 and 4 respectively
Answer» C. 3, 3 and 4 respectively
323.

The dissociation energy of \[{{H}_{2}}\] is \[430.53\text{ }kJmo{{l}^{-1}}\]. If hydrogen is dissociated by illumination with radiation of wavelength 253.7 nm the fraction of the radiant energy which will be converted into kinetic energy is given by

A. 100%
B. 0.0882
C. 2.22%
D. 0.0122
Answer» C. 2.22%
324.

For a first-order homogeneous gaseous reaction \[A\to 2B+C,\] if the total pressure after time t was \[{{P}_{t}}\] and after long time \[(t\to \infty )\] was \[{{P}_{\infty }}\] then k in terms of \[{{P}_{t}},\,{{P}_{\infty }}\] and t is:

A. \[k=\frac{2.303}{t}\log \left( \frac{{{P}_{\infty }}}{{{P}_{\infty }}-{{P}_{t}}} \right)\]
B. \[k=\frac{2.303}{t}\log \left( \frac{2{{P}_{\infty }}}{{{P}_{\infty }}-{{P}_{t}}} \right)\]
C. \[k=\frac{2.303}{t}\log \left( \frac{2{{P}_{\infty }}}{3\left( {{P}_{\infty }}-{{P}_{t}} \right)} \right)\]
D. None of these
Answer» D. None of these
325.

When \[HCl\] gas is passed through saturated solution of \[BaC{{l}_{2}}\], a white ppt. is obtained. This is due to [CPMT 1979]

A. Impurities in \[BaC{{l}_{2}}\]
B. Impurities in \[HCl\]
C. Precipitation of \[BaC{{l}_{2}}\]
D. Formation of complex
Answer» D. Formation of complex
326.

A catalyst is used to                                        [Pb.CET 2000]

A. Increase the product
B. Increase or decrease the rate of reaction
C. Increase or decrease the products
D. Decrease the products
Answer» C. Increase or decrease the products
327.

The molar conductances of \[NaCl,\,HCl\] and \[C{{H}_{3}}COONa\] at infinite dilution are 126.45, 426.16 and \[91\,oh{{m}^{-1}}\,c{{m}^{2}}\,mo{{l}^{-1}}\] respectively. The molar conductance of \[C{{H}_{3}}COOH\] at infinite dilution is             [CBSE PMT 1997]

A. \[201.28\,oh{{m}^{-1}}\,c{{m}^{2}}\,mo{{l}^{-1}}\]
B. \[390.71\,oh{{m}^{-1}}c{{m}^{2}}\,mo{{l}^{-1}}\]
C. \[698.28\,oh{{m}^{-1}}\,c{{m}^{2}}\,mo{{l}^{-1}}\]
D. \[540.48\,oh{{m}^{-1}}c{{m}^{2}}\,mo{{l}^{-1}}\]
Answer» C. \[698.28\,oh{{m}^{-1}}\,c{{m}^{2}}\,mo{{l}^{-1}}\]
328.

2.0 g of a sample contains mixture of \[Si{{O}_{2}}\]and\[F{{e}_{2}}{{O}_{\text{3}}}\]. On very strong heating, it leaves a residue weighing 1.96 g. The reaction responsible for loss of mass is given below.\[F{{e}_{2}}{{O}_{3}}(s)\to F{{e}_{3}}{{O}_{4}}(s)+O(g),\](unbalance equation)What is the percentage by mass of \[Si{{O}_{2}}\] in original sample?

A. 100%
B. 0.2
C. 0.4
D. 0.6
Answer» D. 0.6
329.

The deficiency of vitamin \[{{B}_{1}}\] causes [CPMT 1994; MP PMT 1999; BHU 2000]

A. Beri-beri
B. Scurvy
C. Rickets
D. Anaemia
Answer» B. Scurvy
330.

Enzymes with two sites are called            [AIIMS 2002]

A. Apoenzyme
B. Holoenzyme
C. Allosteric enzyme
D. Conjugate enzyme
Answer» D. Conjugate enzyme
331.

Depletion of ozone layer is caused by [RPMT 2002]

A. Freon
B. Alkane
C. Gringard reagent
D. All of these
Answer» B. Alkane
332.

\[Xe{{O}_{4}}\] molecule is tetrahedral having:

A. Two \[p\pi -d\pi \] bonds
B. One \[p\pi -d\pi \] bonds
C. Four \[p\pi -d\pi \] bonds
D. Three \[p\pi -d\pi \] bonds
Answer» D. Three \[p\pi -d\pi \] bonds
333.

According to VSEPR theory, the most probable shape of the molecule having 4 electron pairs in the outer shell of the central atom is                                  [MP PET 1996, 2001]

A. Linear
B. Tetrahedral
C. Hexahedral
D. Octahedral
Answer» C. Hexahedral
334.

The standard heat of combustion of Al is \[-\,837.8\,kJ\,mo{{l}^{-1}}\] at \[{{25}^{o}}C\]. If Al reacts with \[{{O}_{2}}\] at \[{{25}^{o}}C,\] which of the following releases 250 kcal of heat?

A. The reaction of 0.624 mole of Al
B. The formation of 0.624 mole of \[A{{l}_{2}}{{O}_{3}}\]
C. The reaction of 0.312 mole of Al
D. The formation of 0.150 mole of \[A{{l}_{2}}{{O}_{3}}\]
Answer» C. The reaction of 0.312 mole of Al
335.

State which of the following statements is true?

A. First law of thermodynamics is not adequate in predicting the direction of the process.
B. In an exothermic reaction, the total enthalpy of the products is greater than that of reactants.
C. The standard enthalpy of diamond is zero at 298K and 1 atm pressure.
D. It is possible to calculate the value of \[\Delta H\] for the reaction \[{{H}_{2}}(g)+B{{r}_{2}}(\ell )\to 2HBr(g)\] from the bond enthalpy data.
Answer» B. In an exothermic reaction, the total enthalpy of the products is greater than that of reactants.
336.

The heat of hydration of solution anhydrous \[CuS{{O}_{4}}\] and hydrated \[CuS{{O}_{4}}\cdot 5{{H}_{2}}O\] are - 66.5 and 11.7 kJ \[mo{{l}^{-1}}\]respectively. Calculate the heat of hydration of \[CuS{{O}_{4}}\] to \[CuS{{O}_{4}}\cdot 5{{H}_{2}}O\]

A. - 78.2 kJ
B. - 81.2 kJ
C. - 68.2 kJ
D. - 60.1 kJ
Answer» B. - 81.2 kJ
337.

What is the concentration of nitrate ions if equal volumes of 0.1 M \[AgN{{O}_{3}}\] and 0.1 M \[NaCl\] are mixed together [NCERT 1981; CPMT 1983]

A. 0.1 N
B. 0.2 M
C. 0.05 M
D. 0.25 M
Answer» D. 0.25 M
338.

Ethyl acetoacetate shows, which type of isomerism [Pb. CET 2003]

A. Chain
B. Optical
C. Metamerism
D. Tautomerism
Answer» E.
339.

The acid that results when a base accepts a proton is called         [Kerala (Med.) 2002]

A. Conjugate base of the acid
B. Conjugate protonated base
C. Lewis base
D. Conjugate acid of the base
E. None of these
Answer» E. None of these
340.

Which of the following is true, when components forms an ideal solution?

A. \[\Delta {{H}_{m}}=\Delta {{V}_{m}}=0\]
B. \[\Delta {{H}_{m}}>\Delta {{V}_{m}}\]
C. \[\Delta {{H}_{m}}<\Delta {{V}_{m}}\]
D. \[\Delta {{H}_{m}}=\Delta {{V}_{m}}=1\]
Answer» B. \[\Delta {{H}_{m}}>\Delta {{V}_{m}}\]
341.

Which is not the use of orthoboric acid?

A. As an antiseptic and eye wash.
B. In glass industry.
C. In glazes for pottery.
D. In borax - bead test.
Answer» E.
342.

Two components A and B form an ideal solution. The mole fraction of A and B in ideal solutions are \[{{X}_{A}}\] and  \[{{X}_{B}},\] while that of in vapour phase, these components have their mole fractions as \[{{Y}_{A}}\] and \[{{Y}_{B}}\] then, the slope and intercept of plot of \[\frac{1}{{{Y}_{A}}}\] us \[\frac{1}{{{X}_{A}}}\] will be

A. \[\frac{p_{B}^{0}}{p_{A}^{0}},\frac{p_{A}^{0}-p_{B}^{0}}{p_{A}^{0}}\]
B. \[\frac{p_{B}^{0}}{p_{A}^{0}},\frac{p_{A}^{0}+p_{B}^{0}}{p_{A}^{0}}\]
C. \[\frac{p_{A}^{0}}{p_{B}^{0}},\frac{p_{A}^{0}+p_{B}^{0}}{p_{A}^{0}}\]
D. \[\frac{p_{A}^{0}}{p_{B}^{0}},\frac{p_{A}^{0}}{p_{A}^{0}-p_{B}^{0}}\]
Answer» B. \[\frac{p_{B}^{0}}{p_{A}^{0}},\frac{p_{A}^{0}+p_{B}^{0}}{p_{A}^{0}}\]
343.

A compound contains 54.55 % carbon, 9.09% hydrogen, 36.36% oxygen. The empirical formula of this compound is:

A. \[{{C}_{3}}{{H}_{5}}O\]
B. \[{{C}_{4}}{{H}_{8}}{{O}_{2}}\]
C. \[{{C}_{2}}{{H}_{4}}{{O}_{2}}\]
D. \[{{C}_{2}}{{H}_{4}}O\]
Answer» E.
344.

The number of water molecules in 1 litre of water is [EAMCET 1990]

A. 18
B. \[18\times 1000\]
C. \[{{N}_{A}}\]
D. \[55.55\,{{N}_{A}}\]
Answer» E.
345.

The number of sodium atoms in 2 moles of sodium ferrocyanide is              [BHU 2004]

A. \[12\times {{10}^{23}}\]
B. \[26\times {{10}^{23}}\]
C. \[34\times {{10}^{23}}\]
D. \[48\times {{10}^{23}}\]
Answer» E.
346.

Indicator for the titration of HCl and \[N{{a}_{2}}C{{O}_{3}}\] would be [RPMT 1999]

A. \[{{K}_{4}}Fe{{(CN)}_{6}}\]
B. \[{{K}_{3}}Fe{{(CN)}_{6}}\]
C. Phenolphthalein
D. Methyl orange
Answer» E.
347.

Which of the following aqueous acid is most acidic [AMU 2000]

A. HCl
B. HF
C. HI
D. HBr
Answer» D. HBr
348.

The correct order of the increasing ionic character is [MP PET 2000]

A. \[BeC{{l}_{2}}<MgC{{l}_{2}}<CaC{{l}_{2}}<BaC{{l}_{2}}\]
B. \[BeC{{l}_{2}}<MgC{{l}_{2}}<BaC{{l}_{2}}>CaC{{l}_{2}}\]
C. \[BeC{{l}_{2}}<BaC{{l}_{2}}<MgC{{l}_{2}}<CaC{{l}_{2}}\]
D. \[BaC{{l}_{2}}<CaC{{l}_{2}}<MgC{{l}_{2}}<BeC{{l}_{2}}\]
Answer» B. \[BeC{{l}_{2}}<MgC{{l}_{2}}<BaC{{l}_{2}}>CaC{{l}_{2}}\]
349.

The de Broglie wavelength of a tennis ball of mass 60 g moving with a velocity of 10 metres per second is approximately

A. \[{{10}^{-31}}\]
B. \[{{10}^{-16}}\]
C. \[{{10}^{-25}}\]
D. \[{{10}^{-33}}\]
Answer» E.
350.

The total number of possible isomeric trimethyl benzene is [MP PET 1997]

A. 2
B. 3
C. 4
D. 6
Answer» C. 4