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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.
| 3501. |
Bond order is a concept in the molecular orbital theory. It depends on the number of electrons in the bonding and antibonding orbitals. Which of the following statements is true about it ? The bond order [AIIMS 1980] |
| A. | Can have a negative quantity |
| B. | Has always an integral value |
| C. | Can assume any positive or integral or fractional value including zero |
| D. | Is a nonzero quantity |
| Answer» B. Has always an integral value | |
| 3502. |
\[NaOH\]is prepared by the electrolysis of: |
| A. | aqueous solution of sodium chloride with platinum electrodes |
| B. | molten sodium chloride with graphite anode and iron cathodes |
| C. | sodium carbonate with platinum electrodes |
| D. | sodium carbonate with nickel electrodes |
| Answer» B. molten sodium chloride with graphite anode and iron cathodes | |
| 3503. |
A colorless salt gives violet colour to Bunsen flame and also turns moisture litmus paper blue. It is: |
| A. | \[N{{a}_{2}}C{{O}_{3}}\] |
| B. | \[KN{{O}_{3}}\] |
| C. | \[{{K}_{2}}C{{O}_{3}}\] |
| D. | \[Cu{{(OH)}_{2}}\] |
| Answer» D. \[Cu{{(OH)}_{2}}\] | |
| 3504. |
The order of melting point of chlorides of alkali metals is: |
| A. | LiCl> Nacl> KCl> CsCl |
| B. | LiCl> NaCl> KCl> CsCl |
| C. | NaCl> KCl> CsCl> LiCl |
| D. | LiCl> NaCI> CsCl> KCI |
| Answer» D. LiCl> NaCI> CsCl> KCI | |
| 3505. |
Potassium superoxide (\[K{{O}_{2}}\]) is used in space capsules, submarines, and breathing masks, because it is |
| A. | diamagnetic in nature |
| B. | high melting compound |
| C. | helpful in removing \[C{{O}_{2}}\]and producing \[{{O}_{2}}\] |
| D. | unstable compound |
| Answer» D. unstable compound | |
| 3506. |
Alkli metals react with water vigorously to form hydroxides and dihydrogen. Which of the following alkali metals reacts with water least vigorously? |
| A. | Li |
| B. | Na |
| C. | K |
| D. | Cs |
| Answer» B. Na | |
| 3507. |
The compound sprinkled on road to keep them wet and prevent dust form flying is |
| A. | Calcium hydroxide |
| B. | Calcium chloride |
| C. | Calcium sulphate |
| D. | Calcium hydride |
| Answer» C. Calcium sulphate | |
| 3508. |
Soilium chloride imparts a golden yellow colour to the Bunsen flame. This can be interpreted due to: |
| A. | low ionization potential of sodium |
| B. | photosensitivity of sodium |
| C. | sublimation of metallic sodium to give yellow vapour. |
| D. | emission of excess of energy absorbed as a radiation in the visible region |
| Answer» E. | |
| 3509. |
Sodium when heated in a current of dry ammonia gives |
| A. | Sodium nitrite |
| B. | Sodium hydride |
| C. | Sodium amide |
| D. | Sodium azide |
| Answer» D. Sodium azide | |
| 3510. |
A metal M readily forms sulphate \[MS{{O}_{4}}\]which is water insoluble. It forms oxide MO which becomes inert on heating. It forms insoluble hydroxide which is soluble in NaOH. The metal M is |
| A. | Mg |
| B. | Ba |
| C. | Ca |
| D. | Be |
| Answer» E. | |
| 3511. |
The alkali metals have low melting point. Which of the following alkali metal is expected to melt if the room temperature rises to\[30{}^\circ C\]? |
| A. | Na |
| B. | K |
| C. | Rb |
| D. | Cs |
| Answer» E. | |
| 3512. |
In the manufacture of metallic sodium by the fused salt electrolysis (Down's process) a small amount of calcium chloride is added to |
| A. | improve the electrical conduction |
| B. | increase the temperature of electrolysis |
| C. | Bring down the melting temperature |
| D. | Stabilize the metallic sodium |
| Answer» D. Stabilize the metallic sodium | |
| 3513. |
A metal M readily forms its sulphate \[MS{{O}_{4}}\]which is watersoluble. It forms its oxide MO which becomes inert on heating. It forms its insoluble hydroxide M\[{{(OH)}_{2}}\] which is soluble in NaOH solution. Then M is |
| A. | Mg |
| B. | Ba |
| C. | Ca |
| D. | Be |
| Answer» E. | |
| 3514. |
A solid compound 'X' on heating gives \[C{{O}_{2}}\]gas and a residue. The residue mixed with water forms 'Y' on passing an excess of \[C{{O}_{2}}\]through 'Y' in water a clear solution 'z' is obtained. On boiling 'Z' compound, 'X' is reformed. The compound 'X' us |
| A. | \[Ca{{(HC{{O}_{3}})}_{2}}\] |
| B. | \[CaC{{O}_{3}}\] |
| C. | \[N{{a}_{2}}C{{O}_{3}}\] |
| D. | \[{{K}_{2}}C{{O}_{3}}\] |
| Answer» C. \[N{{a}_{2}}C{{O}_{3}}\] | |
| 3515. |
At higher temperature sodium metal reacts with alumina to give a sodium compounds 'X', 'X' is dissolved in water and then carbon dioxide gas is passed through it, a compound 'Y' us formed. The compound 'X', 'Y' are respectively |
| A. | \[N{{a}_{2}}{{O}_{2}}\] and \[N{{a}_{2}}C{{O}_{3}}\] |
| B. | \[N{{a}_{2}}O\] and \[N{{a}_{2}}C{{O}_{3}}\] |
| C. | \[N{{a}_{2}}{{O}_{2}}\] and \[NaAl{{O}_{2}}\] |
| D. | \[NaAl{{O}_{2}}\] and \[N{{a}_{2}}C{{O}_{3}}\] |
| Answer» C. \[N{{a}_{2}}{{O}_{2}}\] and \[NaAl{{O}_{2}}\] | |
| 3516. |
A and B are two salts. A with dilute HCl and B with cone. \[{{H}_{2}}S{{O}_{4}}\]react to give reddish brown vapours, hence a and B respectively are: |
| A. | NaBr, \[NaN{{O}_{3}}\] |
| B. | \[NaN{{O}_{3}}\], NaBr |
| C. | NaBr,\[NaN{{O}_{2}}\] |
| D. | \[NaN{{O}_{2}}\], NaBr |
| Answer» E. | |
| 3517. |
Sodium cannot be extracted by the electrolysis of brine solution because: |
| A. | Sodium liberated reacts with water to produce \[NaOH+{{H}_{2}}\] |
| B. | Sodium being more electropositive than hydrogen, \[{{H}_{2}}\]is liberated at cathode and not sodium |
| C. | electrolysis cannot take place with brine solution |
| D. | none of the above |
| Answer» C. electrolysis cannot take place with brine solution | |
| 3518. |
A gas does not turn lime water milky, supports the combustion of burning magnesium. It has no smell and is colourless. It extinguishes a glowing splint but under some circumstances reacts with oxygen and hydrogen. It is not poisonous. The gas is likely to be: |
| A. | Nitrogen |
| B. | Water vapour |
| C. | Carbon disoxide |
| D. | Helium |
| Answer» B. Water vapour | |
| 3519. |
Correct order of stability of hydrides of carbon family is |
| A. | \[C{{H}_{4}}>Si{{H}_{4}}>Ge{{H}_{4}}>Sn{{H}_{4}}>Pb{{H}_{4}}\] |
| B. | \[C{{H}_{4}}<Si{{H}_{4}},<Ge{{H}_{4}}<Sn{{H}_{4}}<Pb{{H}_{4}}\] |
| C. | \[C{{H}_{4}}.>Sn{{H}_{4}},>Ge{{H}_{4}}>Sn{{H}_{4}}>Pb{{H}_{4}}\] |
| D. | None of the above |
| Answer» B. \[C{{H}_{4}}<Si{{H}_{4}},<Ge{{H}_{4}}<Sn{{H}_{4}}<Pb{{H}_{4}}\] | |
| 3520. |
An oxide of carbon (X) reacts with ammonia to produce urea an important fertilizer. Which of the following combinations will not Yield (X). |
| A. | \[C{{O}^{2-}}_{3}+HCl\xrightarrow{\Delta }\] |
| B. | \[CaO+C\xrightarrow{\Delta }\] |
| C. | \[C+Excess{{O}_{2}}\xrightarrow{\Delta }\] |
| D. | \[HC{{O}^{-}}_{3}+HCl\xrightarrow{\Delta }\] |
| Answer» C. \[C+Excess{{O}_{2}}\xrightarrow{\Delta }\] | |
| 3521. |
How the reaction below can be made to proceed in forward direction? \[B{{(OH)}_{3}}+NaOH\to [NaB{{(OH)}_{4}}]\,or\,[NaB{{O}_{2}}+{{H}_{2}}O]\] |
| A. | Addition of borax |
| B. | Addition of cis-1, 2-diol |
| C. | Addition of trans-1, 2-diol |
| D. | Addition of \[N{{a}_{2}}HP{{O}_{4}}\] |
| Answer» C. Addition of trans-1, 2-diol | |
| 3522. |
\[BC{{l}_{3}}\]does not exist as dimer but \[B{{H}_{3}}\]exist as dimer (\[{{B}_{2}}{{H}_{6}}\]) because |
| A. | Chlorine is more electronegative than hydrogen |
| B. | There is \[p\pi \]-\[p\pi \]back bonding in \[BC{{l}_{3}}\] but \[B{{H}_{3}}\]does not contain such multiple bonding |
| C. | Large sized chlorine atoms do not fit in between the small boron atoms whereas small sized hydrogen atoms get fitted in between boron atoms |
| D. | None of the above |
| Answer» D. None of the above | |
| 3523. |
The number and types of bonds between two carbon atoms in calcium carbide are |
| A. | One sigma, one pi |
| B. | One sigma, two pi |
| C. | Two sigma, one pi |
| D. | Two sigma, two pi |
| Answer» C. Two sigma, one pi | |
| 3524. |
Among the halides(I) \[BC{{l}_{3}}\] (II) \[AlC{{l}_{3}}\](III) \[GaC{{l}_{3}}\] (IV) \[InC{{l}_{3}}\]The order of decreasing Lewis acid character is: |
| A. | I, II, III, IV |
| B. | II, III, IV, I |
| C. | III, IV, II, I |
| D. | IV, III, II, I |
| Answer» E. | |
| 3525. |
Prussic acid \[+{{O}_{2}}\xrightarrow{Ag}\] The products of the above reaction are: |
| A. | \[{{C}_{2}}{{N}_{2}},{{H}_{2}}O\] |
| B. | \[C{{O}_{2}},{{H}_{2}}O\] |
| C. | \[CO,C{{o}_{2}},{{H}_{2}}O\] |
| D. | \[C{{O}_{2}},{{N}_{2}},{{H}_{2}}O\] |
| Answer» B. \[C{{O}_{2}},{{H}_{2}}O\] | |
| 3526. |
Consider following statements: I: In diamond, each carbon atom is linked tetratedrally to four other carbon atoms by \[s{{p}^{3}}\]bonds. II: Graphite has planar hexagonal layers of carbn atoms held together by planar hexagonal layers of carbon atoms held together by weak van der Waals forces. III: Silicon exists only in diamond structure due to its tendency to form \[p\pi \]-\[p\pi \]bonds to itself. |
| A. | Only I and II are correct |
| B. | Only I is Correct |
| C. | Only II and III are correct |
| D. | All are correct statement |
| Answer» E. | |
| 3527. |
A compound of boron X reacts at \[200{}^\circ C\]temperature with \[N{{H}_{3}}\]to give another compound Y which is called as inorganic benzene. The compound Y is a colourless liquid and is highly light sensitive. Its melting point is \[-57{}^\circ C\]. The compound X with excess of \[N{{H}_{3}}\] and at a still higher temperature gives boron nitride (\[{{(BN)}_{n}}\]). The compounds X and Y are respectively: |
| A. | \[B{{H}_{3}}\] and \[{{B}_{2}}{{H}_{6}}\] |
| B. | \[NaB{{H}_{4}}\]and\[{{C}_{6}}{{H}_{6}}\] |
| C. | \[{{B}_{2}}{{H}_{6}}\]and \[{{B}_{3}}{{N}_{3}}{{H}_{6}}\] |
| D. | \[{{B}_{4}}{{C}_{3}}\]and \[{{C}_{6}}{{H}_{6}}\] |
| Answer» D. \[{{B}_{4}}{{C}_{3}}\]and \[{{C}_{6}}{{H}_{6}}\] | |
| 3528. |
Which of the statement is true for the above sequence of reactions? |
| A. | Z is hydrogen |
| B. | Y is \[LiB{{F}_{4}}\] |
| C. | Z and Y are \[{{F}_{2}}\]and \[{{B}_{2}}{{H}_{6}}\] respectively |
| D. | Z is potassium hydroxide |
| Answer» D. Z is potassium hydroxide | |
| 3529. |
Boron of highest purity (~99.9%)is obtained by |
| A. | Reduction of \[{{B}_{2}}{{O}_{3}}\]by mg. |
| B. | Electrolysis of fused tetrafluoroborates (\[KB{{F}_{4}}\]) in molten KF. |
| C. | Reduction of \[BC{{l}_{3}}\]with \[{{H}_{2}}\]at 1270 K. |
| D. | thermal decomposition of boranes at 1173 K. |
| Answer» D. thermal decomposition of boranes at 1173 K. | |
| 3530. |
Precipitation of \[A{{l}^{3+}}\](aq) \[Al{{(OH)}_{3}}\]by \[C{{O}_{2}}\] shows that |
| A. | The acidic property is very weak |
| B. | The acidic property is very strong |
| C. | The basic property is very strong |
| D. | The basic property is very weak |
| Answer» B. The acidic property is very strong | |
| 3531. |
A certain salt (X) gives the following tests:(i) Its aqueous solution is alkaline to litmus.(ii) On strongly heating it swells to give a glassy bead(iii) When concentrated sulphuric acid is added to hot concentrated solution of (x), crystals of \[{{H}_{3}}B{{O}_{3}}\]separate out. Identify the colour of these crystals. |
| A. | Violet |
| B. | Blue |
| C. | Brown |
| D. | White |
| Answer» E. | |
| 3532. |
Aluminum is more reactive than iron because its standard reduction potential is higher, still aluminum is less easily corroded than iron because: |
| A. | It has higher reducing power and forms self-protective layer of \[A{{l}_{2}}{{O}_{3}}\] |
| B. | It has higher reducing power and does not react with oxygen so easily |
| C. | Al reacts with atmospheric carbon dioxide to form a self-protective layer of \[A{{l}_{2}}{{O}_{3}}+A{{l}_{4}}{{C}_{3}}\] |
| D. | all of the above |
| Answer» B. It has higher reducing power and does not react with oxygen so easily | |
| 3533. |
Aluminum vessels should not be washed with materials containing washing soda since |
| A. | Washing soda is expensive |
| B. | Washing soda is easily decomposed |
| C. | Washing soda reacts with Al to form insoluble aluminum oxide. |
| D. | Washing soda reacts with Al to form soluble aluminate |
| Answer» D. Washing soda reacts with Al to form soluble aluminate | |
| 3534. |
Some of the properties given below are for colloidal sols. (I) Viscosity is same as that of the medium. (II) Extensive hydration takes place. (III) Migration of the particles under electric field. (IV) Particles cannot be detected even under ultramicroscope properties applicable for lyophilic and lyophobic colloidal sols are |
| A. | Lyophilic Lyophobic I and II III and IB |
| B. | Lyophilic Lyophobic I and III II and IV |
| C. | Lyophilic Lyophobic II and IV I and III |
| D. | Lyophilic Lyophobic II and III I and IV |
| Answer» D. Lyophilic Lyophobic II and III I and IV | |
| 3535. |
Select the correct observation in the following isotherm: (where \[\frac{x}{m}\]= amount of the adsorbat adsorbed per gram m of the adsorbent) |
| A. | \[\left( \frac{x}{m} \right)\propto p{}^\circ \] when point (x) is reached |
| B. | Desorption may start along XY |
| C. | \[\left( \frac{x}{m} \right)\propto \,{{(p)}^{1/n}}\]along OX |
| D. | All of the above |
| Answer» E. | |
| 3536. |
Methylene blue in aqueous solution, is adsorbed on activated charcoal at\[25{}^\circ C\]. For this process, the correct statement is |
| A. | The adsorption is accompanied by a decrease in enthalpy |
| B. | The adsorption requires activation at \[25{}^\circ C\] |
| C. | The adsorption increases with increases of temperature |
| D. | The adsorption is irreversible |
| Answer» B. The adsorption requires activation at \[25{}^\circ C\] | |
| 3537. |
I, II and III are three adsorption isotherm at three temperatures\[{{T}_{1}}\], \[{{T}_{2}}\]and \[{{T}_{3}}\] where x is the amount of adsorbate adsorbed on m g of the adsorbent. Temperatures \[{{T}_{1}}\], \[{{T}_{2}}\] and \[{{T}_{3}}\] are in the order |
| A. | \[{{T}_{1}}<{{T}_{2}}<{{T}_{3}}\] |
| B. | \[{{T}_{1}}={{T}_{2}}={{T}_{3}}\] |
| C. | \[{{T}_{3}}<{{T}_{2}}<{{T}_{1}}\] |
| D. | No specific order |
| Answer» B. \[{{T}_{1}}={{T}_{2}}={{T}_{3}}\] | |
| 3538. |
For an adsorption of \[{{H}_{2}}\] on Ni surface \[Ni\left( s \right)+{{H}_{2}}\left( s \right)\to \] adsorbed \[{{H}_{2}}\] on Ni surface Variation of adsorption with temperature is shown in figure. This indicates that |
| A. | it is an exothermic change |
| B. | it is physical adsorption |
| C. | Both [a] and [b] |
| D. | None of the. Above |
| Answer» D. None of the. Above | |
| 3539. |
In the Freundlich adsorption isotherm, \[\log \left( \frac{x}{m} \right)=\log k+\frac{1}{n}\log p\], the value of n is |
| A. | any value from 0 to 1 |
| B. | a positive integer |
| C. | a negative integer |
| D. | a positive or a negative fractional number |
| Answer» C. a negative integer | |
| 3540. |
3 g of activated charcoal was added to 50 mL of acetic acid solution (0.06N) in a flask. After an hour it was filtered and the strength of the filtrate was found to be 0.042 N. The amount of acetic acid adsorbed (per gram of charcoal) is |
| A. | 15 mg |
| B. | 36 mg |
| C. | 42 mg |
| D. | 54 mg |
| Answer» B. 36 mg | |
| 3541. |
The given graphs/data I, II, III and IV represent General trends observed for different physisorption and chemisorption processes under mild conditions of temperature and pressure. Which of the following choices about I, II, III and IV are correct? (I) (II) (III) (IV) |
| A. | I is physisorption and II is chemisorption |
| B. | I is physisorption and III is chemisorption |
| C. | IV is chemisorption and III is chemisorption |
| D. | IV is physisorption and III is chemisorption |
| Answer» B. I is physisorption and III is chemisorption | |
| 3542. |
Gold number of protective colloids A, B, and D are 0.50, 0.01, 0.1, and 0.005 respectively. The correct order of their protective power is |
| A. | D<A<C<B |
| B. | C<B<D<A |
| C. | A<C<B<D |
| D. | B<D<A<C |
| Answer» D. B<D<A<C | |
| 3543. |
Identify the correct statement regarding enzymes: |
| A. | Enzymes are specific biological catalysts that well-defined active sites |
| B. | Enzymes are normally heterogeneous catalysts that are very specific in their action |
| C. | Enzymes are specific biological catalyst that cannot be poisoned |
| D. | Enzymes are specific biological catalyst that can normally function at very high temperature (T=1000K) |
| Answer» C. Enzymes are specific biological catalyst that cannot be poisoned | |
| 3544. |
Which of the following reactions leads to the formation of a substance in the colloidal state? |
| A. | \[Cu+HgC{{l}_{2}}\to CuC{{l}_{2}}+Hg\] |
| B. | \[2HN{{O}_{3}}+3{{H}_{2}}S\to 3S+4{{H}_{2}}O+2NO\] |
| C. | \[2Mg+C{{O}_{2}}\to 2MgO+C\] |
| D. | \[Cu+CuC{{l}_{2}}\to C{{u}_{2}}C{{l}_{2}}\] |
| Answer» C. \[2Mg+C{{O}_{2}}\to 2MgO+C\] | |
| 3545. |
Milk can be preserved by adding a few drops of |
| A. | Formic acid solution |
| B. | formaldehyde solution |
| C. | Acetic acid solution |
| D. | Acetaldehyde solution |
| Answer» C. Acetic acid solution | |
| 3546. |
Gold number of some lyophilic sols are: I : Casein : 0.01 II : Haemoglobin : 0.03 III : Gum Arabic : 0.15 V : Sodium oleate : 0.40 Which has maximum protective power? |
| A. | I |
| B. | II |
| C. | III |
| D. | IV |
| Answer» B. II | |
| 3547. |
A sol has positively charged colloidal particles. Which of the following solutions is required in lowest concentration for coagulation? |
| A. | NaCl |
| B. | \[{{K}_{4}}[Fe{{(CN)}_{6}}]\] |
| C. | \[ZnC{{l}_{2}}\] |
| D. | \[N{{a}_{2}}S{{O}_{4}}\] |
| Answer» C. \[ZnC{{l}_{2}}\] | |
| 3548. |
A reddish brown sol is obtained by adding small quantity of \[FeC{{l}_{3}}\]solution to freshly prepared and well washed \[Fe{{(OH)}_{3}}\] ppt. fixed layer and mobile layer are represented as |
| A. | \[\left[ FeC{{l}_{3}} \right]F{{e}^{3+}}\] \[O{{H}^{-}}\] |
| B. | \[\left[ Fe{{(OH)}_{3}} \right]F{{e}^{3+}}\] \[C{{I}^{-}}\] |
| C. | \[\left[ Fe{{(OH)}_{3}} \right]F{{e}^{3+}}\] \[3C{{I}^{-}}\] |
| D. | \[\left[ FeC{{l}_{3}} \right]F{{e}^{3+}}\] \[3O{{H}^{-}}\] |
| Answer» D. \[\left[ FeC{{l}_{3}} \right]F{{e}^{3+}}\] \[3O{{H}^{-}}\] | |
| 3549. |
Which of the following mixture will lead to the formation of negatively charged colloid? |
| A. | \[50\text{ }ml\text{ }of\text{ }0.1\text{ }M\,AgN{{O}_{3}}+\text{ }50\text{ }ml\text{ }of\text{ }0.1\text{ }M\text{ }KI\] |
| B. | \[50\text{ }ml\text{ }of\text{ }0.1\text{ }M\,AgN{{O}_{3}}+\text{ }50\text{ }ml\text{ }of\text{ }0.2\text{ }M\text{ }KI\] |
| C. | \[50\text{ }ml\text{ }of\text{ }0.2\text{ }M\,AgN{{O}_{3}}+\text{ }50\text{ }ml\text{ }of\text{ }0.1\text{ }M\text{ }KI\] |
| D. | \[50\text{ }ml\text{ }of\text{ }0.2\text{ }M\,AgN{{O}_{3}}+\text{ }50\text{ }ml\text{ }of\text{ }0.2\text{ }M\text{ }KI\] |
| Answer» C. \[50\text{ }ml\text{ }of\text{ }0.2\text{ }M\,AgN{{O}_{3}}+\text{ }50\text{ }ml\text{ }of\text{ }0.1\text{ }M\text{ }KI\] | |
| 3550. |
Chemical adsorption |
| A. | increases with increase in temperature |
| B. | decreases with increase in temperature |
| C. | First increases then decreases with increase in temperature |
| D. | First decreases then increases with increase in temperature |
| Answer» D. First decreases then increases with increase in temperature | |