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MCQOPTIONS
This section includes 1187 Mcqs, each offering curated multiple-choice questions to sharpen your NEET knowledge and support exam preparation. Choose a topic below to get started.
| 601. |
The differential rate law for the reaction \[{{H}_{2}}(g)+{{I}_{2}}(g)\to 2HI(g)\] is |
| A. | \[-\frac{d[{{H}_{2}}]}{dt}=-\frac{d[{{I}_{2}}]}{dt}=-\frac{d[HI]}{dt}\] |
| B. | \[\frac{d[{{H}_{2}}]}{dt}=\frac{d[{{I}_{2}}]}{dt}=\frac{1}{2}\frac{d[HI]}{dt}\] |
| C. | \[\frac{1}{2}\frac{d[{{H}_{2}}]}{dt}=\frac{1}{2}\frac{d[{{I}_{2}}]}{dt}=-\frac{d[HI]}{dt}\] |
| D. | \[-2\frac{d[{{H}_{2}}]}{dt}=-2\frac{d[{{I}_{2}}]}{dt}=\frac{d[HI]}{dt}\] |
| Answer» E. | |
| 602. |
The plot of concentration of the reactant Vs time for a reaction is a straight line with a negative slope. The reaction follows a rate equation of |
| A. | zero order |
| B. | first order |
| C. | second order |
| D. | third order |
| Answer» B. first order | |
| 603. |
Units of rate constant of first and zero order reactions in terms of molarity M unit are respectively |
| A. | \[se{{c}^{-1}},\text{ }M.se{{c}^{-1}}\] |
| B. | \[se{{c}^{-1}},\text{ }M\] |
| C. | \[M.se{{c}^{-1}},\text{ }se{{c}^{-1}}\] |
| D. | \[M,\text{ }se{{c}^{-1}}\] |
| Answer» B. \[se{{c}^{-1}},\text{ }M\] | |
| 604. |
The reaction \[2{{N}_{2}}{{O}_{5}}\rightleftharpoons 2{{N}_{2}}{{O}_{4}}+{{O}_{2}}\] |
| A. | bimolecular and of second order |
| B. | unimolecular and of first order |
| C. | bimolecular and of first order |
| D. | bimolecular and of zero order |
| Answer» D. bimolecular and of zero order | |
| 605. |
For the reaction, \[2{{N}_{2}}{{O}_{5}}\to 4N{{O}_{2}}+{{O}_{2}}\] the rate equation can be expressed in two ways\[-\frac{d[{{N}_{2}}{{O}_{5}}]}{dt}=k[{{N}_{2}}{{O}_{5}}]\] and \[+\frac{d[N{{O}_{2}}]}{dt}=k'[{{N}_{2}}{{O}_{5}}]\] k and k' are related as: |
| A. | \[k=k'\] |
| B. | \[2k=k'\] |
| C. | \[k=2k'\] |
| D. | \[k=4k'\] |
| Answer» C. \[k=2k'\] | |
| 606. |
\[A+2B\to C\], the rate equation for this reaction is given as Rate \[=K\left[ A \right]\left[ B \right].\] If the concentration of A is kept the same but that of B is doubled what will happen to the rate itself? |
| A. | halved |
| B. | the same |
| C. | doubled |
| D. | quadrupled |
| Answer» D. quadrupled | |
| 607. |
Consider the consecutive reactions: \[A\xrightarrow{k=2\times {{10}^{-5}}{{s}^{-1}}}B\xrightarrow{k=8\times {{10}^{-6}}{{s}^{-1}}}\]\[C\xrightarrow{k=3\times {{10}^{-3}}{{s}^{-1}}}D\] The rate determining step of the reaction is: |
| A. | \[A\to B\] |
| B. | \[C\to D\] |
| C. | \[B\to C\] |
| D. | \[A\to D\] |
| Answer» D. \[A\to D\] | |
| 608. |
For the reaction\[A+B\xrightarrow{{}}C+D\]. The variation of the concentration of the products is given by the curve |
| A. | Z |
| B. | Y |
| C. | W |
| D. | X |
| Answer» C. W | |
| 609. |
Consider the two hypothetical reactions given below:I \[a\text{ }A\to \]Products, \[k=x\,mo{{l}^{-1}}\text{ }L\text{ }mi{{n}^{-1}}\]II \[bB\to \]Products, \[k=y\,mi{{n}^{-1}}\]The half-lives of both the reactions are the same, equal to 1 hr when molar concentration of the reactant is 1.0 M in each case. If these reactions are started at the same time taking 1M of the reactant in each case, the ratio [A]/[B] after 3 hr will be: |
| A. | 0.5 |
| B. | 4 |
| C. | 1 |
| D. | 2 |
| Answer» E. | |
| 610. |
A reaction takes place in various steps. The rate constant for first, second, third and fifth steps are \[{{k}_{1}},{{k}_{2}},{{k}_{3}}\] and \[{{k}_{4}}\] respectively The overall rate constant is given by \[k=\frac{{{k}_{2}}}{{{k}_{3}}}{{\left( \frac{{{k}_{1}}}{{{k}_{5}}} \right)}^{1/2}}\]. If activation energy are 40,60,50 and 10 kJ/mol respectively, the overall energy of activation (kJ/ mol) is: |
| A. | 10 |
| B. | 20 |
| C. | 25 |
| D. | none of these |
| Answer» D. none of these | |
| 611. |
Consider the reaction \[A\to 2B+C,\Delta H=-15\]kcal. The energy of activation of backward reaction is\[20\text{ }kcal\text{ }mo{{l}^{-1}}\]. In presence of catalyst the energy of activation of forward reaction is \[3\text{ }kcal\text{ }mo{{l}^{-1}}\]. At 400 K. the catalyst causes the rate of the reaction to increase by the number of times equal to |
| A. | \[{{e}^{3.5}}\] |
| B. | \[{{e}^{2.5}}\] |
| C. | \[{{e}^{-\,2.5}}\] |
| D. | \[{{e}^{2.303}}\] |
| Answer» C. \[{{e}^{-\,2.5}}\] | |
| 612. |
In the Arrhenius plot of ln k Vs\[\frac{1}{T}\], a linear plot is obtained with a slope of \[-2\times {{10}^{4}}K.\] The energy of activation of the reaction (in\[kJ\text{ }mol{{e}^{-1}}\]) is (R value is\[8.3J\text{ }{{K}^{-1}}mo{{l}^{-1}}\]) |
| A. | 83 |
| B. | 166 |
| C. | 249 |
| D. | 332 |
| Answer» C. 249 | |
| 613. |
The rate of reaction is doubled for every \[10{}^\circ C\] rise in temperature. The increase in reaction rate as a result of temperature rise from \[10{}^\circ C\] to \[100{}^\circ C\] is |
| A. | 112 |
| B. | 512 |
| C. | 400 |
| D. | 614 |
| Answer» C. 400 | |
| 614. |
The minimum energy a molecule should possess in order to enter into a fruitful collision is known as |
| A. | reaction energy |
| B. | collision energy |
| C. | activation energy |
| D. | threshold energy |
| Answer» E. | |
| 615. |
In respect of the equation \[k=A{{e}^{-Ea/RT}}\] in chemical kinetics, which one of the following statements is correct? |
| A. | A is adsorption factor |
| B. | \[{{E}_{a}}\]is energy of activation |
| C. | R is Rydberg's constant |
| D. | k is equilibrium constant |
| Answer» C. R is Rydberg's constant | |
| 616. |
In a reaction, \[2A\to \] products, the concentration of A decreases from 0.50 M to 0.38 M in 10 min. What is the rate of reaction (in\[M\text{ }{{s}^{-1}}\]) during this interval? |
| A. | 0.012 |
| B. | 0.024 |
| C. | \[2\times {{10}^{-3}}\] |
| D. | \[2\times {{10}^{-4}}\] |
| Answer» E. | |
| 617. |
The reactions rate \[{{N}_{2}}\left( g \right)+3{{H}_{2}}\left( g \right)\to 2N{{H}_{3}}\left( g \right)\]was measured\[\frac{d[N{{H}_{3}}]}{dt}=2\times {{10}^{-4}}mol\,{{\sec }^{-1}}\]. The rates of reactions expressed in terms of \[{{N}_{2}}\]and \[{{H}_{2}}\] are |
| A. | Rate in terms of \[{{N}_{2}}\] \[(mol\,{{L}^{-1}}se{{c}^{-1}})\]Rate in terms of \[{{H}_{2}}\] \[(mol\,{{L}^{-1}}se{{c}^{-1}})\]\[2\times {{10}^{-4}}\]\[2\times {{10}^{-4}}\] |
| B. | Rate in terms of \[{{N}_{2}}\] \[(mol\,{{L}^{-1}}se{{c}^{-1}})\]Rate in terms of \[{{H}_{2}}\] \[(mol\,{{L}^{-1}}se{{c}^{-1}})\]\[3\times {{10}^{-4}}\]\[1\times {{10}^{-4}}\] |
| C. | Rate in terms of \[{{N}_{2}}\] \[(mol\,{{L}^{-1}}se{{c}^{-1}})\]Rate in terms of \[{{H}_{2}}\] \[(mol\,{{L}^{-1}}se{{c}^{-1}})\]\[1\times {{10}^{-4}}\]\[3\times {{10}^{-4}}\] |
| D. | Rate in terms of \[{{N}_{2}}\] \[(mol\,{{L}^{-1}}se{{c}^{-1}})\]Rate in terms of \[{{H}_{2}}\] \[(mol\,{{L}^{-1}}se{{c}^{-1}})\]\[2\times {{10}^{-1}}\]\[2\times {{10}^{-3}}\] |
| Answer» D. Rate in terms of \[{{N}_{2}}\] \[(mol\,{{L}^{-1}}se{{c}^{-1}})\]Rate in terms of \[{{H}_{2}}\] \[(mol\,{{L}^{-1}}se{{c}^{-1}})\]\[2\times {{10}^{-1}}\]\[2\times {{10}^{-3}}\] | |
| 618. |
The rate law for the reaction \[2X+Y\to Z\] is Rate \[=k\left[ X \right]\left[ Y \right].\] The correct statement with regard to this relation is |
| A. | the unit of k is \[{{s}^{-1}}\] |
| B. | the rate of the reaction is independent of [X] and [Y] |
| C. | for this reaction \[{{t}_{1/2}}\] is independent of initial concentrations of reactant |
| D. | the rate of formation of Z is half of the rate of disappearance of X |
| Answer» E. | |
| 619. |
For a reaction\[A+2B\to C\], the amount of C formed by starting the reaction with 5 moles of A and 8 moles of B is |
| A. | 5 moles |
| B. | 8 moles |
| C. | 16 moles |
| D. | 4 moles |
| Answer» E. | |
| 620. |
The half-life of a reaction is inversely proportional to the square of the initial concentration of the reactant. Then the order of the reaction is |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» E. | |
| 621. |
For a reaction, the rate constant is expressed as\[k=A{{e}^{-40000/T}}\]. The energy of the activation is |
| A. | 40000 cal |
| B. | 88000 cal |
| C. | 80000 cal |
| D. | 8000 cal |
| Answer» D. 8000 cal | |
| 622. |
A catalyst lowers the activation enegy of a reaction from \[20kJ\text{ }mo{{l}^{-1}}\] to\[10kJ\text{ }mo{{l}^{-1}}\]. The temperature at which the uncatalyzed reaction will have the same rate as that of the catalyzed at \[27{}^\circ C\] is |
| A. | \[-123{}^\circ C\] |
| B. | \[327{}^\circ C\] |
| C. | \[32.7{}^\circ C\] |
| D. | \[+23{}^\circ C\] |
| Answer» C. \[32.7{}^\circ C\] | |
| 623. |
Which of the following reactions is not of the first order? |
| A. | Inversion of sucrose in the presence of acid |
| B. | Acid-catalyzed hydrolysis of ethyl acetate |
| C. | Hydrolysis of tertiary butyl halide using alkali |
| D. | Oxidation of \[{{I}^{-}}\] ion by \[{{S}_{2}}O_{8}^{2-}\] ion |
| Answer» E. | |
| 624. |
The half-life of a radioactive element is 20 min. The time interval between the stages of its 33% and 67% decay is |
| A. | 40 min |
| B. | 20 min |
| C. | 30min |
| D. | 25 min |
| Answer» C. 30min | |
| 625. |
For a certain reaction, rate\[=k\times {{\left[ {{H}^{+}} \right]}^{n}}\]. If pH of reaction changes from two to one, the rate becomes 100 times of its value at pH = 2, the order of reaction is- |
| A. | 1 |
| B. | 2 |
| C. | 0 |
| D. | 3 |
| Answer» C. 0 | |
| 626. |
The rate law for the reaction below is given by the expression k [A] [B] \[A+B\to Product\] If the concentration of B is increased from 0.1 to 0.3 mole, keeping the value of A at 0.1 mole, the rate constant will be: |
| A. | 3k |
| B. | 9k |
| C. | k/3 |
| D. | k |
| Answer» E. | |
| 627. |
Two vitamins absorbed from intestine along with fast are |
| A. | A, D |
| B. | A, B |
| C. | A, C |
| D. | D, B |
| Answer» B. A, B | |
| 628. |
The hormone which controls the processes of burning of fats, proteins and carbohydrates to liberate energy in the body is |
| A. | cortisone |
| B. | adrenaline |
| C. | thyroxine |
| D. | insulin |
| Answer» E. | |
| 629. |
Night blindness is caused by deficiency of |
| A. | vitamin \[{{B}_{12}}\] |
| B. | vitamin A |
| C. | vitamin C |
| D. | vitamin E |
| Answer» C. vitamin C | |
| 630. |
\[D-\left( + \right)-Glucose~\xrightarrow{5{{\left( C{{H}_{3}}CO \right)}_{2}}O}D-\left( + \right)-Glucose\] pentaacetate Which statement is true about glucose pentaacetate? |
| A. | It will react with phenylhydrazine but not with Tollens' reagent. |
| B. | It will react with Tollens' reagent but not with phenylhydrazine. |
| C. | It will react with both of the above mentioned reagents. |
| D. | It will react neither with phenylhydrazine nor with Tollens' reagent. |
| Answer» E. | |
| 631. |
Which of the following enzyme converts starch into maltose? |
| A. | Diastase |
| B. | Maltase |
| C. | Zymase |
| D. | Invertase |
| Answer» B. Maltase | |
| 632. |
Among the following organic acids, the acid present in rancid butter is: |
| A. | Pyruvicacid |
| B. | Lactic acid |
| C. | Butyric acid |
| D. | Acetic acid |
| Answer» D. Acetic acid | |
| 633. |
The reason for double helical structure of DNA is the operation of: |
| A. | Electrostatic attractions |
| B. | van der Waals forces |
| C. | Dipole - Dipole interactions |
| D. | Hydrogen bonding |
| Answer» E. | |
| 634. |
All of the following statements apply to proteins except |
| A. | Proteins generally have no definite melting point |
| B. | Proteins contain the grouping -CONH- |
| C. | Proteins have high molecular weight |
| D. | Proteins can only contain the elements C, H, O and N. |
| Answer» E. | |
| 635. |
\[H-C\equiv C-H\xrightarrow[{{H}_{2}}S{{O}_{4}}]{HgS{{O}_{4}}}(A)\] \[\xrightarrow[(2)\,{{H}_{3}}{{O}^{+}}]{(1)\,N{{H}_{3}}+HCN}(B);\] Product [B] of given reaction is: |
| A. | Glycine |
| B. | Alanine |
| C. | valine |
| D. | Leucine |
| Answer» C. valine | |
| 636. |
Iso-electric point of alanine is (pH = 6). At which pH, maximum concentration of zwitter ion of alanine will be present? |
| A. | pH>6 |
| B. | pH<6 |
| C. | pH=6 |
| D. | pH=7 |
| Answer» D. pH=7 | |
| 637. |
Which is correct statement? |
| A. | Starch is a polymer of \[\alpha \]-glucose |
| B. | In cyclic structure of fructose, there are four carbons and one oxygen atom |
| C. | Amylose is a component of cellulose |
| D. | Proteins are composed of only one type of amino acids |
| Answer» B. In cyclic structure of fructose, there are four carbons and one oxygen atom | |
| 638. |
Which of the following is not present in a nucleotide? |
| A. | Guanine |
| B. | Cytosine |
| C. | Adenine |
| D. | Tyrosine |
| Answer» E. | |
| 639. |
Which of the following substances is not present in nucleic acids? |
| A. | Cytosine |
| B. | Adenine |
| C. | Thymine |
| D. | Guanidine |
| Answer» E. | |
| 640. |
The process by which synthesis of protein takes place based on the genetic information present in m-RNA is called |
| A. | Translation |
| B. | Transcription |
| C. | Replication |
| D. | Messenger hypothesis |
| Answer» B. Transcription | |
| 641. |
A sequence of how many nucleotides in messenger RNA makes a codon for an amino acid? |
| A. | Three |
| B. | Four |
| C. | One |
| D. | Two |
| Answer» B. Four | |
| 642. |
Vitamin \[{{B}_{6}}\] is known as |
| A. | pyridoxine |
| B. | thiamine |
| C. | tocopherol |
| D. | riboflavin |
| Answer» B. thiamine | |
| 643. |
Which is not a true statement? |
| A. | \[\alpha \]-carbon of \[\alpha \]-amino acid is asymmetric |
| B. | All proteins are found in L-form |
| C. | Human body can synthesize all proteins they need |
| D. | At pH = 7 both amino acids and carboxylic groups exist in the ionised form |
| Answer» C. Human body can synthesize all proteins they need | |
| 644. |
Which amino acid is achiral? |
| A. | alanine |
| B. | valine |
| C. | proline |
| D. | None of these |
| Answer» E. | |
| 645. |
Imino acid among these compounds is |
| A. | serine |
| B. | proline |
| C. | tyrosine |
| D. | lysine |
| Answer» C. tyrosine | |
| 646. |
In cells the net production of ATP molecules generated from one glucose molecule is |
| A. | 46 |
| B. | 32 |
| C. | 36 |
| D. | 40 |
| Answer» D. 40 | |
| 647. |
Compounds I and II may be grouped as |
| A. | diastereomers |
| B. | epimers |
| C. | C-2 epimers |
| D. | all of the three. |
| Answer» E. | |
| 648. |
The enantiomer of \[\alpha -D-\left( + \right)\]-glucose is |
| A. | \[\beta -D-\left( + \right)\]-glucose |
| B. | \[\alpha -D-\left( - \right)\] -glucose |
| C. | \[\alpha -L-\left( - \right)\]-glucose |
| D. | \[\beta -L-\left( - \right)\]-glucose. |
| Answer» D. \[\beta -L-\left( - \right)\]-glucose. | |
| 649. |
What will happen when D-(+)-glucose is treated with methanolic \[-HCl\] followed by Tollens' reagent? |
| A. | A black ppt. will be formed |
| B. | A red ppt. will be formed |
| C. | A green colour will appear |
| D. | No characteristic colour or ppt. will be formed. |
| Answer» E. | |
| 650. |
Which of the following carbohydrates is not related to (+)-glucose? |
| A. | Amylopectin |
| B. | Amylose |
| C. | Inulin |
| D. | Glycogen |
| Answer» D. Glycogen | |