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Medical
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Which of the following structures represents neoprene polymer?

  • Option 1)

    option 1

  • Option 2)

    option 2

  • Option 3)

    option 3

  • Option 4)

    option 3

 
As we learnt in Neoprene - - Formed by free radical polymerization of chloroprene ( 2-chloro-1, 3-butadiene ). - Homopolymer - wherein - Superior resistance to vegetable and mineral oils. - Used in manufacturing conveyor belts, gaskets, hoses.    Neoprene is a polymer of chloroprene. Structure: Option 1) This option is correct Option 2) This option is incorrect Option 3) This option is...
Medical
120 Views   |  

Which of the following alkaline earth metal sulphates has hydration enthalpy higher than the lattice enthalpy?

  • Option 1)

    C_{a}SO_{4}

  • Option 2)

    B_{e}SO_{4}

  • Option 3)

    B_{a}SO_{4}

  • Option 4)

    S_{r}SO_{4}

 
    Solubility of sulphates of alkaline metals - Solubility in water decreases from Be to Ba - wherein   Lattice energy is constant whereas hydration energy decreases from            Among alkaline earth metal sulphates, lattice energy remains almost constant as we go down the group but hydration enthalpy decreases dramatically. Sa,   has higher hydration enthalpy than its lathia...
Medical
112 Views   |  

Property of the alkaline earth metals that increases with their automic number 

  • Option 1)

    Solubility of their hydroxides in water

  • Option 2)

    Solubility of their sulphates  in water

  • Option 3)

    Ionization energy

  • Option 4)

    Electronegavity

 
As learned in concept no Solubility of hydroxides alkaline earth metals - Increases from Be to Ba - wherein Due to the decrease in lattice energy    Solubility of hydroxides of alkaline earth metals increases down the grouo from Be ta BA due to a decrease in lattice energy Option 1) Solubility of their hydroxides in water This is correct option Option 2) Solubility of their sulphates  in...
Medical
129 Views   |  

The compound A on heating gives a colourless gas and a residue that is dissolved in water to obtain B. Excess of CO_{2} is bubbled through aqueous solution of B, C is formed which is recovered in the solid form. Solid C on gentle heating gives back A. The compound is

  • Option 1)

    C_{a}SO_{4}. 2H_{2}O

  • Option 2)

    C_{a}CO_{3}

  • Option 3)

    Na_{2}CO_{3}

  • Option 4)

    K_{2}CO_{3}

 
As we learned in concept no Calcium oxide/quick lime/time - Its aqueous suspension is known as slaked lime, - wherein     Action heat on CaCO3 - Decomposes to evolve carbon di oxide - wherein     Action of CO2 on limewater - Turns milky due to the formation of calcium carbonate - wherein       Option 1) This is incorrect  option Option 2) This is correct  option Option 3) This is...
Medical
509 Views   |  

A solution of sucrose (molar mass=342 g mol-1) has been prepared by dissolving 68.5 g of sucrose in 1000 g of water. The freezing point of the solution obtained will be (Kf for water=1.86 K kg mol-1)

  • Option 1)

    -0.372°C

  • Option 2)

    -0.520°C

  • Option 3)

    +0.372°C

  • Option 4)

    -0.570°C

 
As we learned in concept Mathematical Expression of Depression in Freezing point -   - wherein m = molarity of solvent  = cryoscopic  constant     molal depress const Units =                         =                     =   Option 1) -0.372°C This option is correct. Option 2) -0.520°C This option is incorrect. Option 3) +0.372°C This option is incorrect. Option 4) -0.570°C This option...
Medical
105 Views   |  

Match list - 1 (Equations) with list - 2  (Type of processes) and select the correct option

    List 1                                                                            List 2

  Equations                                                                    Type pf process

(1) K_{p}> Q                                                                                            (i) Non spontaneous

(2) \Delta G^{o}< RT\ In\ Q                                                                         (ii) Equilibrium

(3) K_{p}=Q                                                                                             (iii) spontaneous and endothermic

(4) T> \frac{\Delta H}{\Delta S}                                                                                          (iv) spontaneous

  • Option 1)

                 (1)        (2)       (3)     (4)

                   (ii)         (i)        (iv)    (iii)
     

  • Option 2)

                (1)        (2)       (3)     (4)

                (i)         (ii)        (iii)    (iv)
     

  • Option 3)

               (1)        (2)       (3)     (4)

               (iii)         (iv)        (ii)    (i)

     

  • Option 4)

                 (1)        (2)       (3)     (4)

                 (iv)         (i)        (ii)    (iii)

 
  Gibb's free energy (? G) -   - wherein Gibb's free energy enthalpy of reaction entropy temperature    At ,  this shows reaction is spontaneous , reaction is at equilibrium. ,  reaction is spontaneous and endothermic. Option 1)              (1)        (2)       (3)     (4)                (ii)         (i)        (iv)    (iii)   Incorrect Option Option 2)             (1)       ...
Medical
127 Views   |  

For vaporization of water at 1 atmospheric pressure, the values of \Delta H \ and \ \Delta S are 40.63kJmol^{-1} and 108.8JK^{-1}mol^{-1}, respectivily. The temperature when Gibbs energy change \left ( \Delta G \right ) for this transformation will be zero, is:

  • Option 1)

    293.4K

  • Option 2)

    273.4K

  • Option 3)

    393.4K

  • Option 4)

    373.4K

 
  Gibb's free energy (? G) -   - wherein Gibb's free energy enthalpy of reaction entropy temperature    According to Gibbs equation when   or = 373.43K Option 1) 293.4K Incorrect Option Option 2) 273.4K Incorrect Option Option 3) 393.4K Incorrect Option Option 4) 373.4K Correct Option
Medical
92 Views   |  

The tendency of BF_{3} , BCl_{3} and BBr_{3}  to behave as Lewis acid decrease in the sequence:

  • Option 1)

    BCl_{3}> BF_{3}> BBr_{3}

  • Option 2)

    BBr_{3}> BCl_{3}> BF_{3}

  • Option 3)

    BBr_{3}> BF_{3}> BCl_{3}

  • Option 4)

    BF_{3}> BCl_{3}> BBr_{3}

 
  @11865 - wherein   Due to small size and high electronegativity     Lewis acid character of Boron trihalides obey the order :   is a weak lewis acid because of lock bonding between the 2p ortibals of F and vacant 2p ortibals of B. This result in fall of the electron dificient nature of and lewis it a number lewis acid. Such back bonding is not possible in   and due to huge difference in...
Medical
87 Views   |  

Standard entropies of X_{2}, Y_{2} and XY_{3} are 60, 40 and 50JK^{-1}mol^{-1} respectively. For the reaction

\frac{1}{2}X_{2}+\frac{3}{2}Y_{2}\leftrightharpoons , XY_{3},\Delta H=-30kJ

 

to be at equilibrium, the temperature should be:

  • Option 1)

    750K

  • Option 2)

    1000K

  • Option 3)

    1250K

  • Option 4)

    500K

 
  Spontanous process -   - wherein For spontanouse process must be negative.    given reaction is We Know    at  equilibrium                          Option 1) 750K Correct Option 2) 1000K Incorrect Option 3) 1250K Incorrect Option 4) 500K Incorrect
Medical
97 Views   |  

If \Delta U and \Delta W  represent the increase in internal energy and work done by the system respectively in a thermodynamical process, which of the following is true? 

  • Option 1)

    \Delta U=-\Delta W, in an adiabatic process

  • Option 2)

    \Delta U=\Delta W, in an isothermal process

  • Option 3)

    \Delta U=\Delta W, in an adiabatic process

  • Option 4)

    \Delta U=-\Delta W, in an isothermal process

 
Using First law in Isothermal Process -   - wherein Isothermal process Heat supplied is equal to work done.    and Adiabatic Process - When a Thermodynamic System undergoes a change in such a way that no exchange of heat takes place. - wherein    In adiabatic process,  In isothermal process,  Option 1)  in an adiabatic process This option is correct Option 2)  in an...
Medical
1825 Views   |  

An engine pumps water through a hose pipe . Water passes through the pipe and leaves it with a velocity of 2 m/s. The mass per unit length of water in the pipe is 100 kg/m. What is the power of the engine?

  • Option 1)

    400 W

  • Option 2)

    200 W

  • Option 3)

    100 W

  • Option 4)

    800 W

 
As discussed in Power if the force is constant - - wherein   Mass per unit length of water,  Velocity of water  Power of the engine                                   Option 1) 400 W This solution is incorrect Option 2) 200 W This solution is incorrect Option 3) 100 W This solution is incorrect Option 4) 800 W This solution is correct
Medical
100 Views   |  

Which one of the following compounds is a peroxide?

  • Option 1)

    KO_{2}

  • Option 2)

    BaO_{2}

  • Option 3)

    MnO_{2}

  • Option 4)

    NO_{2}

 
As we learned in concept Basic oxides of oxygen - Alkali, Alkaline earth and transition metals form basic oxides  - wherein Na2O,MgO,Fe2O3    When in a compound, the oxidation state of oxygen is -1 and is released on reaction with dilute acids, that compound has peroxide linkage. , let x be the O.S. of 0 then +2 + 2(x) = 0                    Dx = -1 Also, gives on reaction with dilute...
Medical
459 Views   |  

A ball moving with velocity 2 m/s collides head on with another stationary ball of double the mass. If the coefficient of restitution is 0.5, then their velocities (in m/s) after collision will be

  • Option 1)

    0, 1

  • Option 2)

    1, 1

  • Option 3)

    1, 0.5

  • Option 4)

    0, 2

 
As discussed in concept Coffecient of Restitution (e) - - wherein Ratio of relative velocity after collision to relative velocity before collision.      - (i) From conservation of momentum  - (ii) From equation (i)  From equation (ii)  and  Option 1) 0, 1 This solution is correct Option 2) 1, 1 This solution is incorrect Option 3) 1, 0.5 This solution is incorrect Option 4) 0, 2 This...
Medical
102 Views   |  

Oxidiation states of P in H_{4}P_{2}O_{5}, H_{4}P_{2}O_{6}, and H_{4}P_{2}O_{7}, are respectively

  • Option 1)

    +3, +5, +4

  • Option 2)

    +5, +3, +4

  • Option 3)

    +5, +4, +3

  • Option 4)

    +3, +4, +5

 
As learnt Hypophosphoric Acid - H4P2O6 (+4), tetrabasic - wherein       Phosphorus Acid - H3PO3 (+3), dibasic - wherein       Orthophosphoric Acid - H3PO4 (+5), tribasic - wherein     , let x be the O.S. of P then, 4+2x+5(-2)=0        , let x be the O.S. of P then, 4+2x+6(-2)=0         , let x be the O.S. of P then, 4+2x+7(-2)=0     Option 1) +3, +5, +4 This option is incorrect Option...
Medical
108 Views   |  

Match List-I (substances) with List-II with List-II (processes) employed in the manufacture of the substances and select the correct option.

  List-I List-II
  Substances Processes
1. Sulphuric acid (i) Haber's process
2. Steel (ii) Bessemer's process
3. Sodium hydroxide (iii) Leblanc process
4. Ammonia (iv) Contact process
  • Option 1)

    Code:

                1          2          3           4

              (iv)       (ii)        (iii)         (i)

  • Option 2)

    Code:

                1          2          3           4

              (i)          (iv)       (ii)         (iii)

     

  • Option 3)

    Code:

                1          2          3           4

               (i)         (ii)        (iii)        (iv)

  • Option 4)

    Code:

                1          2          3           4

              (iv)        (iii)        (ii)        (i)

 
  Manufacture of ammonia by Haber's process - Mixture of pure N2 and H2 (ration 1:3 by volume) passed over finely divided Fe (catalyst) and Mo (promoter) -     Contact Process - In this process SO2 obtained by burning of S or iron pyrites which is catalytically oxidised to  in presence of timely divided Pt or  as catalyst -     Contact Process -     -    Haber's process: manufacture of...
Medical
85 Views   |  

How many bridging oxygen atoms are present in P_{4}O_{10}?

  • Option 1)

    5

  • Option 2)

    6

  • Option 3)

    4

  • Option 4)

    2

 
As we learnt in Phosphorus pentaoxide - P4O10, white solid, formed when P4 is burnt in excess of air - wherein     Structure of Phosphorus Pentaoxide,  Clearly, there are 6 bridging oxygen atoms.  Option 1) 5 This option is incorrect. Option 2) 6 This option is correct. Option 3) 4 This option is incorrect. Option 4) 2 This option is incorrect.
Medical
92 Views   |  

Which of the following species is not electrophilic in nature?

  • Option 1)

    \overset {\bigoplus }{N}O_{2}

  • Option 2)

    \overset {\bigoplus }{Cl}

  • Option 3)

    BH_{3}

  • Option 4)

    H_{3}\overset {\bigoplus }{O}

 
As we learnt in Positively charged electrophiles - Chemical species having capacity to attack e- rich portion of substance. - wherein     Electrophiles are electron deficient species among the given H3O+ has  lone pair of electron for donation, thus, it is not electron deficient and hence does not behave like an electrophile.   Option 1) Incorrect Option 2) Incorrect Option...
Medical
232 Views   |  

Among the given compounds, the most susceptible to nucleophilic attack at the carbonyl group is:

  • Option 1)

    CH_{3}COOCH_{3}

  • Option 2)

    CH_{3}CONH_{2}

  • Option 3)

    CH_{3}COOCOCH_{3}

  • Option 4)

    CH_{3}COCl

 
As we learnt in Nucleophile - Those e- rich  chemical species having capacity to attack e-deficient portion of substrate. - wherein Nucleophile must have complete octet and atleast one lone pair    Lesser the electron density of acyl carbon atom, more is the susceptibility of a nucleophile attack.  The Cl atom has strong -I effect and weakest + R effect. Because of the weak  bond between the...
Medical
215 Views   |  

Given are cyclohexanol; (I) acetic acid (II), 2, 4, 6 - trinitrophenol (III) and phenol (IV) . In these the order of decreasing acidic character will be:

  • Option 1)

    III > II > IV > I

  • Option 2)

    II > III > I > IV

  • Option 3)

    II > III > IV > I

  • Option 4)

    III > IV > II > I

 
As we learnt in Stability due to resonance - More the no of resonating structure more is the stability. - wherein     in(iii), there are three group which have both - I and -M effect hence it is most stabilized aftet donating H+. Because of resonance it is more stable.    Option 1) III > II > IV > I Correct Option 2) II > III > I > IV Incorrect Option 3) II > III > IV > I Incorrect Option...
Medical
85 Views   |  

A ray of light travelling in a transpatent medium of refractive index \mu, falls on a surface separating the medium from air at an angle of incidence of 45^{\circ}. For which of the following value of \mu the ray can undergo total internal reflection?

  • Option 1)

    \mu =1.33

  • Option 2)

    \mu=1.40

  • Option 3)

    \mu =1.50

  • Option 4)

    \mu =1.25

 
  Critical angle - = Refractive index of rarer medium / Refractive index of denser medium - wherein When angle of incidence of a travelling from a dence medium to rarer medium is greater than critical angle, no refraction occurs.    For total internal reflection   =>   or  Only value satisfy this is    Option 1) This is incorrect answer  Option 2) This is correct answer  Option 3) This...
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