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.

10851.

The \[pH\] of a \[{{10}^{-9}}M\] solution of \[HCl\] in water is [UPSEAT 2000, 02]

A. 8
B. ? 8
C. Between 7 and 8
D. Between 6 and 7
Answer» E.
10852.

Which of the following factors will favour the reverse reaction in a chemical equilibrium [AIIMS 1982]

A. Increase in the concentration of one of the reactants
B. Removal of at least one of the product at regular time intervals
C. Increase in the concentration of one or more products
D. None of these
Answer» D. None of these
10853.

For a weak acid, the incorrect statement is [Pb. PMT 2004]

A. Its dissociation constant is low
B. Its \[p{{K}_{a}}\] is very low
C. It is partially dissociated
D. Solution of its sodium salt is alkaline in water
Answer» C. It is partially dissociated
10854.

A buffer solution can be prepared from a mixture of [IIT 1999; KCET 1999; MP PMT 2002]

A. Sodium acetate and acetic acid in water
B. Sodium acetate and hydrochloric acid in water
C. Ammonia and ammonium chloride in water
D. Ammonia and sodium hydroxide in water
Answer» B. Sodium acetate and hydrochloric acid in water
10855.

0.2 molar solution of formic acid is ionized 3.2%. Its ionization constant is [MP PMT 1991]

A. \[1\times {{10}^{-12}}\]
B. \[2.1\times {{10}^{-4}}\]
C. \[1.25\times {{10}^{-6}}\]
D. \[1\times {{10}^{-14}}\]
Answer» C. \[1.25\times {{10}^{-6}}\]
10856.

For a weak acid \[HA\] with dissociation constant \[{{10}^{-9}},\,\,pOH\] of its 0.1 M solution is [CBSE PMT 1989]

A. 9
B. 3
C. 11
D. 10
Answer» E.
10857.

0.5 M ammonium benzoate is hydrolysed to 0.25 percent, hence its hydrolysis constant is [MH CET 2004]

A. \[2.5\times {{10}^{-5}}\]
B. \[1.5\times {{10}^{-4}}\]
C. \[3.125\times {{10}^{-6}}\]
D. \[6.25\times {{10}^{-4}}\]
Answer» D. \[6.25\times {{10}^{-4}}\]
10858.

On the velocity in a reversible reaction, the correct explanation of the effect of catalyst is [MP PMT 1987]

A. It provides a new reaction path of low activation energy
B. It increases the kinetic energy of reacting molecules
C. It displaces the equilibrium state on right side
D. It decreases the velocity of backward reaction
Answer» B. It increases the kinetic energy of reacting molecules
10859.

\[2N{{O}_{2}}\]⇌\[2NO+{{O}_{2}};\,\,K=1.6\times {{10}^{-12}}\] \[NO+\frac{1}{2}{{O}_{2}}\]⇌\[N{{O}_{2}}{K}'=?\] [CPMT 1996]

A. \[{K}'=\frac{1}{{{K}^{2}}}\]
B. \[{K}'=\frac{1}{K}\]
C. \[{K}'=\frac{1}{\sqrt{K}}\]
D. None of these
Answer» D. None of these
10860.

In a reversible reaction, the catalyst ­­[KCET 2003]

A. Increases the activation energy of the backward reaction
B. Increases the activation energy of the forward reaction
C. Decreases the activation energy of both, forward and backward reaction
D. Decreases the activation energy of forward reaction
Answer» D. Decreases the activation energy of forward reaction
10861.

In the reaction, \[{{A}_{2}}(g)+4{{B}_{2}}(g)\]⇌ \[2A{{B}_{4}}(g)\] \[\Delta H<0\]the formation of \[A{{B}_{4}}\]is will be favoured at [IIT Screening 1990; MP PET 2004]

A. Low temperature, high pressure
B. High temperature, low pressure
C. Low temperature, low pressure
D. High temperature, high pressure
Answer» B. High temperature, low pressure
10862.

The concentration of hydrogen ion in water is [MP PET 1990]

A. 8
B. \[1\times {{10}^{-7}}\]
C. 7
D. \[1/7\]
Answer» C. 7
10863.

In which one of the following gaseous equilibria \[{{K}_{p}}\] is less than \[{{K}_{c}}\] [EAMCET 1989; MP PET 1994; Pb. PMT 2000; KCET 2001; CBSE PMT 2002]

A. \[{{N}_{2}}{{O}_{4}}\]⇌ \[2N{{O}_{2}}\]
B. \[2HI\]⇌\[{{H}_{2}}+{{I}_{2}}\]
C. \[2S{{O}_{2}}+{{O}_{2}}\]⇌ \[2S{{O}_{3}}\]
D. \[{{N}_{2}}+{{O}_{2}}\] ⇌ \[2NO\]
Answer» D. \[{{N}_{2}}+{{O}_{2}}\] ⇌ \[2NO\]
10864.

The aqueous solution of \[CuS{{O}_{4}}\] is [CPMT 1985]

A. Acidic
B. Basic
C. Neutral
D. Amphoteric
Answer» B. Basic
10865.

Which of the following statements is true about photochemical smog?

A. It is reducing in nature.
B. It is formed in winter.
C. It is a sulphurous smog.
D. Components of the smog, NO and \[{{O}_{3}}\], irritate the nose and throat and their high concentration causes headache, chest pain, dryness of the throat, cough and difficulty in breathing.
Answer» E.
10866.

Leaded petrol used to be the primary source of air-borne lead emission. This problem has been overcome by

A. using TEL loaded petrol
B. using ethanol-mixed petrol
C. using unleaded petrol
D. Using MTBE loaded petrol
Answer» D. Using MTBE loaded petrol
10867.

Consider following sets: Blue colour solution changes to colourless (or fades) in

A. I, II, III
B. I, II
C. II, III
D. I, III
Answer» E.
10868.

The standard EMF of a cell having one electron change is found to be 0.591 V at \[\text{25}{}^\circ \text{C}\]. The equilibrium constant of the reaction is:

A. \[1.0\times {{10}^{30}}\]
B. \[1.0\times {{10}^{5}}\]
C. \[1.0\times {{10}^{10}}\]
D. \[1.0\times {{10}^{1}}\]
Answer» D. \[1.0\times {{10}^{1}}\]
10869.

The same quantity of electricity was passed through two electrolytic cells containing a salt of metal X and zinc sulphate solution respectively using platinum electrode. 0.468 g of metal X and 1.532 g of Zn were deposited. The equivalent mass of X is (At. wt. of Zn is 65.4 u)

A. 9.98 g/equiv
B. 3.2 g/equiv
C. 5.9 g/equiv
D. 0.99 g/equiv
Answer» B. 3.2 g/equiv
10870.

The standard electrode potential for the following reaction is +1.33V. What is the potential at \[pH=2.0\]? \[C{{r}_{2}}{{O}_{7}}^{2-}(aq.1M)+14\,{{H}^{+}}(aq)+6{{e}^{-}}\xrightarrow{{}}\] \[2C{{r}^{3+}}(aq.\,1\,M)+7{{H}_{2}}O(\ell )\]

A. +1.820 V
B. +1.990 V
C. +1.608 V
D. +1.0542 V
Answer» E.
10871.

For the following cell reaction \[Pb(s)+H{{g}_{2}}S{{O}_{4}}(s)PbS{{O}_{4}}(s)+2Hg(l)\] \[E_{cell}^{o}=0.92V\] \[{{K}_{sp}}(PbS{{O}_{4}})=2\times {{10}^{-8}},\]\[{{K}_{sp}}(H{{g}_{2}}S{{O}_{4}})=1\times {{10}^{-6}}\] Hence, \[{{E}_{cell}}\] is

A. 0.92 V
B. 0.89 V
C. 1.04 V
D. 0.95 V
Answer» E.
10872.

Resistance of a conductivity cell filled with a solution of an electrolyte of concentration 0.1 M is 100 ohm. The conductivity of this solution is 1.29 S/m. Resistance of the same cell filled with 0.02 M of the same solution if the electrolyte is 520 ohm. The molar conductivity of 0.02 M solution of electrolyte would be:

A. \[124\times {{10}^{-4}}S-{{m}^{2}}/mol\]
B. \[1240\times {{10}^{-4}}S-{{m}^{2}}/mol\]
C. \[1.24\times {{10}^{-4}}S-{{m}^{2}}/mol\]
D. \[12.4\times {{10}^{-4}}S-{{m}^{2}}/mol\]
Answer» B. \[1240\times {{10}^{-4}}S-{{m}^{2}}/mol\]
10873.

The electrolysis of acetate solution produces ethane according to reaction:\[2C{{H}_{3}}CO{{O}^{-}}\xrightarrow{{}}{{C}_{2}}{{H}_{6}}(g)+2C{{O}_{2}}(g)+2{{e}^{-}}\]The current efficiency of the process is 80%. What volume of gases would be produced at \[\text{27}{}^\circ \text{C}\] and 740 torr, if the current of 0.5 A is passed through the solution for 96.45 min?

A. 6.0 L
B. 0.60 L
C. 1.365 L
D. 0.91 L
Answer» E.
10874.

The temperature coefficient of a cell whose operation is based on the reaction\[Pb(s)+HgC{{l}_{2}}(aq)\xrightarrow{{}}PbC{{l}_{2}}(aq)+Hg(l)\]\[{{\left( \frac{dE}{dT} \right)}_{p}}=1.5\times {{10}^{-4}}V/K\,at\,298K\]The change in entropy (in J/K mol) during the operation is:

A. 8627
B. 57.9
C. 28.95
D. 14.475
Answer» D. 14.475
10875.

The resistance of 0.1N acetic acid when measured in a cell with cell constant \[1.5\,c{{m}^{-1}}\] is \[5.250\,\Omega \]. The value of \[{{\lambda }_{eq}}\] of \[0.1\,N\,AcOH\] is

A. 60
B. 90
C. 18.4
D. 0.023
Answer» B. 90
10876.

Salts of A (atomic weight: 7), B (atomic weight: 27), and C (atomic weight: 48) were electrolyzed under identical condition using the same quantity of electricity. It was found that when 2.1 got A was deposited, the weights of B and C deposited were 2.7 and 7.2 g, respectively. The valencies of A, B and C, respectively are:

A. 3, 1 and 2
B. 1, 3 and 2
C. 3, 1 and 3
D. 2, 3 and 2
Answer» C. 3, 1 and 3
10877.

Which of the following is correct statement-

A. Conductivity & molar conductivity of solution increase on dilution
B. Voltage of button cell remain unchanged throughout its life time
C. On electrolysis of aqueous \[CuS{{O}_{4}}\] using platinum electrode its concentration \[[C{{u}^{2+}}]\] remain constant
D. On electrolysis of aqueous \[NaCl,\] solution becomes acidic
Answer» C. On electrolysis of aqueous \[CuS{{O}_{4}}\] using platinum electrode its concentration \[[C{{u}^{2+}}]\] remain constant
10878.

Galvanic cell involves

A. conversion of thermal energy (Heating) into electrical energy
B. conversion of electrical energy into chemical energy
C. conversion of chemical energy into thermal energy
D. conversion of chemical energy into electrical energy
Answer» E.
10879.

When a lead storage battery is discharged, then

A. \[S{{O}_{2}}\] is evolved
B. lead is formed
C. lead sulphate is consumed
D. sulphuric acid is consumed
Answer» E.
10880.

The equivalent conductances of two strong electrolytes a infinite dilution in \[{{H}_{2}}O\] (where ions move freely througl a solution) at \[25{}^\circ C\]are given below \[{{\Lambda }^{o}}_{C{{H}_{3}}COONa}=91.0\,\,S\,\,c{{m}^{2}}\text{/}\,Eq\] \[{{\Lambda }^{o}}_{HCl}=426.2\,\,S\,\,c{{m}^{2}}\text{/}\,Eq\] What additional information/ quantity one needs to calculate \[\Lambda {}^\circ \]of an aqueous solution of aceti acid?

A. \[\Lambda {}^\circ \]of \[NaCl\]
B. \[\Lambda {}^\circ \]of\[C{{H}_{3}}\]COOK
C. The limiting equivalent conductance of \[{{H}^{+}}(\lambda _{{{H}^{+}}}^{\circ })\]
D. \[\Lambda {}^\circ \]of chloroaceti cacid (Cl\[C{{H}_{2}}\]COOH)
Answer» B. \[\Lambda {}^\circ \]of\[C{{H}_{3}}\]COOK
10881.

For\[Ag\to A{{g}^{+}}+{{e}^{-}},\] \[E{}^\circ =-0.798V\] \[{{V}^{2+}}+V{{O}^{2+}}+2{{H}^{+}}\to 2{{V}^{3+}}+{{H}_{2}}O,\] \[E\text{ }\!\!{}^\circ\!\!\text{ }=-0.614\text{ }V\] \[{{V}^{3+}}+A{{g}^{+}}+{{H}_{2}}O\to V{{O}^{2+}}+2{{H}^{+}}+Ag,\] \[E{}^\circ =-\,0.438\text{ }V\] Then \[E{}^\circ \]for the reaction \[{{V}^{3+}}+{{e}^{-}}\to {{V}^{2+}}\] is

A. + 0.255V
B. \[-\,0.255\,V\]
C. \[-\,0.254\,V\]
D. \[-\,1.055\,V\]
Answer» C. \[-\,0.254\,V\]
10882.

Given\[l\text{/}a=0.5\,c{{m}^{-1}}\], R = 50 ohm, N = 1.0. The equivalent conductance of the electrolytic cell is

A. \[100\,oh{{m}^{-1}}c{{m}^{2}}g\,E{{q}^{-1}}\]
B. \[20\,oh{{m}^{-1}}c{{m}^{2}}g\,E{{q}^{-1}}\]
C. \[300\,oh{{m}^{-1}}c{{m}^{2}}g\,E{{q}^{-1}}\]
D. \[10\,oh{{m}^{-1}}c{{m}^{2}}g\,E{{q}^{-1}}\]
Answer» E.
10883.

Given standard electrode potentials \[F{{e}^{++}}+2{{e}^{-}}\,\to \,Fe\,;\,\,\,\,{{E}^{o}}=-0.440\,\,V\] \[F{{e}^{+++}}+3{{e}^{-}}\,\to \,Fe\,;\,\,\,\,{{E}^{o}}=-0.036\,\,V\] The standard electrode potential \[({{E}^{o}})\] for \[F{{e}^{+++}}+{{e}^{-}}\to \,F{{e}^{++}}\] is [AIIMS 1982]

A. ? 0.476 V
B. ? 0.404 V
C. + 0.404 V
D. + 0.771 V
Answer» E.
10884.

For a spontaneous reaction the \[\Delta G,\] equilibrium constant (K) and \[E_{Cell}^{o}\] will be respectively [AIEEE 2005]

A. \[-ve,\,>1,\,+ve\]
B. \[+ve,\,>1,\,-ve\]
C. \[-ve,\,<1,\,-ve\]
D. \[-ve,\,>1,\,-ve\]
Answer» B. \[+ve,\,>1,\,-ve\]
10885.

The \[{{E}^{0}}_{{{M}^{3+}}/{{M}^{2+}}}\]values for \[Cr,\ Mn,\ Fe\]and \[Co\]are \[-0.41,\ +1.57,\ +0.77\]and \[+1.97\ V\] respectively. For which one of these metals the change in oxidation state from \[+2\] to \[+3\]is easiest [AIEEE 2004]

A. \[Fe\]
B. Mn
C. Cr
D. Co
Answer» D. Co
10886.

The correct name of \[[Pt{{(N{{H}_{3}})}_{4}}C{{l}_{2}}]\,\,[PtC{{l}_{4}}]\] is [MP PET 2003]

A. Tetraammine dichloro platinum (iv) tetrachloro platinate (ii)
B. Dichloro tetra ammine platinium (iv) tetrachloro platinate (ii)
C. Tetrachloro platinum (ii) tetraammine platinate (iv)
D. Tetrachloro platinum (ii) dichloro tetraammine platinate (iv)
Answer» B. Dichloro tetra ammine platinium (iv) tetrachloro platinate (ii)
10887.

The pair of the compounds in which both the metals are in the highest possible oxidation state is [IIT-JEE (Screening) 2004]

A. \[{{[Fe{{(CN)}_{6}}]}^{3-}},{{[Co{{(CN)}_{6}}]}^{3-}}\]
B. \[Cr{{O}_{2}}C{{l}_{2}},MnO_{4}^{-}\]
C. \[Ti{{O}_{3}},Mn{{O}_{2}}\]
D. \[{{[Co{{(CN)}_{6}}]}^{3-}},Mn{{O}_{3}}\]
Answer» C. \[Ti{{O}_{3}},Mn{{O}_{2}}\]
10888.

The complex chlorocompound diaquatriammine cobalt (III) chloride is represented as [CBSE PMT 2002]

A. \[[Co{{(N{{H}_{3}})}_{3}}\,{{({{H}_{2}}O)}_{3}}]C{{l}_{2}}\]
B. \[[Co{{(N{{H}_{2}})}_{3}}\,\,{{({{H}_{2}}O)}_{2}}]C{{l}_{2}}\]
C. \[[CoCl{{(N{{H}_{3}})}_{3}}\,\,{{({{H}_{2}}O)}_{2}}]C{{l}_{3}}\]
D. \[[CoCl{{(N{{H}_{3}})}_{3}}\,\,{{({{H}_{2}}O)}_{2}}]C{{l}_{2}}\]
Answer» E.
10889.

The IUPAC name of \[\left[ Co{{\left( N{{H}_{3}} \right)}_{6}} \right]C{{l}_{3}}\] is [IIT-JEE 1994]

A. Hexammine cobalt (III) chloride
B. Hexammine cobalt (II) chloride
C. Triammine cobalt (III) trichloride
D. None of these
Answer» B. Hexammine cobalt (II) chloride
10890.

Pick out the complex compound in which the central metal atom obeys EAN rule strictly [KCET 2003]

A. \[{{K}_{4}}[Fe{{(CN)}_{6}}]\]
B. \[{{K}_{3}}[Fe{{(CN)}_{6}}]\]
C. \[[Cr{{({{H}_{2}}O)}_{6}}]\,C{{l}_{3}}\]
D. \[[Cu{{(N{{H}_{3}})}_{4}}]\,S{{O}_{4}}\]
Answer» B. \[{{K}_{3}}[Fe{{(CN)}_{6}}]\]
10891.

The EAN of iron in potassium ferricyanide is [Pb. CET 2000]

A. 18
B. 54
C. 35
D. 23
Answer» D. 23
10892.

The oxidation number of Cr in \[[Cr{{(N{{H}_{3}})}_{6}}]C{{l}_{3}}\] is [CBSE PMT 2001]

A. 8
B. 6
C. 4
D. 3
Answer» E.
10893.

In \[{{K}_{4}}\left[ Fe{{\left( CN \right)}_{6}} \right],\] the E.A.N. of \[Fe\] is [DCE 2000]

A. 33
B. 35
C. 36
D. 26
Answer» D. 26
10894.

Among the ligands \[N{{H}_{3}}\], en, \[C{{N}^{-}}\] and CO, the correct order of their increasing field strength is

A. CO <\[N{{H}_{3}}\]<en<\[C{{N}^{-}}\]
B. \[N{{H}_{3}}\]<en<\[C{{N}^{-}}\]<CO
C. \[C{{N}^{-}}\]<\[N{{H}_{3}}\]<CO<en
D. en <\[C{{N}^{-}}\]<\[N{{H}_{3}}\]<CO
Answer» C. \[C{{N}^{-}}\]<\[N{{H}_{3}}\]<CO<en
10895.

Match Column I with Column II and select the con- answer with respect to hybridisation using the codes gr below: Column I (Complex) Column II (Hybridisation) (I) \[{{[Au{{F}_{4}}]}^{-}}\] (P) \[ds{{p}^{2}}\]hybridisation (II) \[{{[Cu{{(CN)}_{4}}]}^{3-}}\] (Q) \[ds{{p}^{3}}\]hybridisation (III) \[{{[Cu{{({{C}_{2}}{{O}_{4}})}_{3}}]}^{3-}}\] (R) \[s{{p}^{3}}\,{{d}^{2}}\]hybridisation (IV) \[{{[Fe{{({{H}_{2}}O)}_{5}}NO]}^{2+}}\] (S) \[{{d}^{2}}s{{p}^{3}}\]hybridisation Codes:

A. (I)\[\to \]Q, (II)\[\to \]P, (III)\[\to \]R, (IV)\[\to \]S
B. (I)\[\to \]P, (II)\[\to \]Q, (III)\[\to \]S, (IV)\[\to \]R
C. (I)\[\to \]P, (II)\[\to \]Q, (III)\[\to \]R, (IV)\[\to \]S
D. (I)\[\to \]Q, (II)\[\to \]P, (III)\[\to \]S, (IV)\[\to \]R
Answer» C. (I)\[\to \]P, (II)\[\to \]Q, (III)\[\to \]R, (IV)\[\to \]S
10896.

The correct order of increasing order of oxidising power is [DCE 2000]

A. \[{{F}_{2}}<C{{l}_{2}}<B{{r}_{2}}<{{I}_{2}}\]
B. \[{{F}_{2}}<B{{r}_{2}}<C{{l}_{2}}<{{I}_{2}}\]
C. \[C{{l}_{2}}<B{{r}_{2}}<{{F}_{2}}<{{I}_{2}}\]
D. \[{{I}_{2}}<B{{r}_{2}}<C{{l}_{2}}<{{F}_{2}}\]
Answer» E.
10897.

Metallic nature and basic nature of the oxides ........ as we move along a period

A. Increases
B. Decreases
C. First increases then decreases
D. Remains constant
Answer» C. First increases then decreases
10898.

Beryllium and aluminium exhibit many properties which are similar. But, the two elements differ in [AIEEE 2004]

A. Forming covalent halides
B. Forming polymeric hydrides
C. Exhibiting maximum covalency in compounds
D. Exhibiting amphoteric nature in their oxides
Answer» D. Exhibiting amphoteric nature in their oxides
10899.

Strongest reducing agent is [RPMT 1997]

A. \[C{{l}_{2}}\]
B. \[C{{l}^{-}}\]
C. \[B{{r}^{-}}\]
D. \[{{I}^{-}}\]
Answer» E.
10900.

Which of the following gas does not have an octet or eight electrons in the outer shell [CBSE PMT 2001]

A. Ne
B. Ar
C. Rn
D. He
Answer» E.