New ! Chemistry MCQ Practise Tests



Sample 1 Mark Book Back Questions (New Syllabus) 2020

12th Standard

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Chemistry

Time : 00:40:00 Hrs
Total Marks : 64

    Part A

    64 x 1 = 64
  1. In the extraction of copper from its sulphide ore, the metal is finally obtained by the reduction of cuprous oxide with________.

    (a)

    Iron sulphide (FeS)

    (b)

    Carbon monoxide (CO)

    (c)

    Copper (I) sulphide (Cu2S)

    (d)

    Sulphur dioxide (SO2)

  2. Sulphide ore is converted to oxide form by using the process________.

    (a)

    Calcination

    (b)

    Roasting

    (c)

    Smelting

    (d)

    Leaving

  3. Which one of the following compounds has similar structure to that of graphite?

    (a)

    Boron nitride

    (b)

    Boron Carbide

    (c)

    Aluminium Carbide

    (d)

    Aluminium Oxide

  4. On moving down the group 13, density ______

    (a)

    decreases

    (b)

    increases

    (c)

    First decreases then increases

    (d)

    remains same

  5. Which of the following halides of group 15 is not hydrolysed?

    (a)

    NF3

    (b)

    PF3

    (c)

    NI3

    (d)

    Both (a) and (b)

  6. Pick the wrong one among the following

    (a)

    F2 - Yellow

    (b)

    Br2 - Red

    (c)

    Cl2 - Colourless

    (d)

    I2- Violet

  7. Which of the following is wrong with respect to lanthanide contraction?

    (a)

    Decrease in ionic radii

    (b)

    Increase in tendency to act as reducing agents

    (c)

    Decrease in basic character

    (d)

    Resembles second and third row of d-block elements

  8. Ce (Z=58) and Yb (Z=70) exhibits stable +4 and +2 oxidation states respectively. This is because_______.

    (a)

    Ce4+ and Yb2+acquire f7 configuration

    (b)

    Ce4+ and Yb2+ acquire f0 configuration

    (c)

    Ce4+ and Yb2+acquire fand f14 configuration

    (d)

    Ce4+and Yb2+ acquire f0 and f14 configuration

  9. The general electronic configuration of d-block elements can be written as ________.

    (a)

    [Noble gas]n - 1d1-10 ns1-2

    (b)

    [Noble gas]n - 1d-10 n1-6

    (c)

    [Noble gas]n - 2 d10 ns1-2

    (d)

    [Noble gas]n - 2 d10 ns1-6

  10. Primary and secondary valencies of Cu in [Cu(NH3)4]SO4 is _______.

    (a)

    4,4

    (b)

    2,4

    (c)

    4,1

    (d)

    4,2

  11. According to CFT, five d-orbitals of an octahedral complex split to give _______.

    (a)

    One orbital with lower energy and four orbitals with higher energy

    (b)

    Two orbitals with lower energy and three orbitals with higher energy

    (c)

    Three orbitals with lower energy and two orbitals with higher energy

    (d)

    Four orbitals with lower energy and one orbital with higher energy.

  12. Which is not an anionic complex?

    (a)

    [Cu(NH3)4]Cl2

    (b)

    K4[Fe(CN)6]

    (c)

    K3[Fe(CN)6]

    (d)

    [NiCl4]2-

  13. In co-ordination complexes, ligand ammonia is written as _______.

    (a)

    ammine

    (b)

    amine

    (c)

    ammonal

    (d)

    none of these

  14. The structure of hexaaquatitanium (III) ion is _______.

    (a)

    [Ti(H2O)6]3+

    (b)

    [Ti(H2O)6]3-

    (c)

    [Ti(H2O)5]H2O

    (d)

    [Ti(H2O)6]

  15. A solid with formula ABC3 would probably have, _______.

    (a)

    A at body centre, B at face centres and C at corners of the cube

    (b)

    A at corners of cube, B at body centre, C at face centre

    (c)

    A at corners of hexagon, B at centres of the hexagon and C inside the hexagonal unit cell

    (d)

    A at corner, B at face centre, C at body centre

  16. If 'a' is the length of unit cell, then which one is correct relationship?

    (a)

    For simple cubic lattice, radius of metal atom =\(\frac{a}{2}\)

    (b)

    For bee lattice, radius of metal atom \(=\frac { \sqrt { 3a } }{ 4 } \)

    (c)

    For fcc lattice, radius of metal atom \(=\frac { a }{ 2\sqrt { 2 } } \)

    (d)

    All of these

  17. An element with atomic mass 60 having fee structure has a density of 6.23g/cm3. What is the edge length of unit cell?

    (a)

    200 Pm

    (b)

    300 Pm

    (c)

    400 Pm

    (d)

    500 Pm

  18. An excess of potassium ion makes KCl crystals appear violet since _______.

    (a)

    Some of anionic sites are occupied by unpaired electron

    (b)

    Anionic sites are occupied by pair of electrons

    (c)

    both (a) and (b)

    (d)

    neither (a) nor (b)

  19. The coordination number of Zn in ZnO and Zn in ZnS are respectively________.

    (a)

    4 and 6

    (b)

    4 and 4

    (c)

    2 and 4

    (d)

    4 and 3

  20. The number of chloride ions that surrounds the central Na ion in NaCl crystal is_______.

    (a)

    12

    (b)

    8

    (c)

    6

    (d)

    4

  21. If electrical conductivity is found to be same in all directions through a solid the substance is ________ solid and the property is called _________.

    (a)

    crystalline, isotropy

    (b)

    amorphous, isotropy

    (c)

    crystalline, anisotropy

    (d)

    amorphous, isotropy

  22. What would be the rate of disappearance of oxygen, if the rate of formation of nitric oxide (NO) is 3.6 x 10-3mol L-1 s-1?

    (a)

    4 x 10-3mol L-1s-1

    (b)

    4 x 10-3mol-1 L-1s-1

    (c)

    4.5 x 10-3mol L-1s-1

    (d)

    4.5 x 10-3mol-1 L-1s-1

  23. A+B \(\longrightarrow \) C; ∆H = 60 kJ mol-1 Eaf = 150 kJ. What is the activation energy of the backward reaction?

    (a)

    210 kJ

    (b)

    105 kJ

    (c)

    90 kJ

    (d)

    145 kJ

  24. Which of the following does not affect the rate of reaction?

    (a)

    Amount of the reactant taken

    (b)

    Physical state of the reactant

    (c)

    ∆H of reaction

    (d)

    Size of vessel

  25. What will be the rate constant of a order reaction if its half life is given to be 20 min?

    (a)

    13.86 min-1

    (b)

    28.86 min-1

    (c)

    3.47 x 10-2 min-1

    (d)

    None of these

  26. The unit of zero order rate constant is  _____.

    (a)

    litre mol-1 sec-1

    (b)

    mol litre-1 sec-1

    (c)

    sec-1

    (d)

    litre2 sec-1

  27. The value of rate constant of a pseudo first order reaction______.

    (a)

    Independent on the concentration of reactants present in small amount

    (b)

    Depends on the concentration of reactants present in excess

    (c)

    Independent of the concentration of reactants

    (d)

    Depends only on temperature.

  28. The oxidation of potassium iodide by potassium persulphate as per the rate law, rate k[K2S2O8] [K1]. The order with respect to potassium iodide is, _______.

    (a)

    two

    (b)

    one

    (c)

    three

    (d)

    four

  29. In a second order reaction, if one of the concentration is excess, the order of the reaction is ________ order reaction.

    (a)

    first

    (b)

    pseudo first

    (c)

    third

    (d)

    zero

  30. Analyses the equilibrium
    HClO4 +H2O ⇌ H3O+ \({ ClO }_{ 4 }^{ - }\)
    and choose the correct statement.

    (a)

    H3O+ is the conjugate base of H2O

    (b)

    CIO4- is the conjugate base of HCIO4

    (c)

    H2O is the conjugate acid of H3O+

    (d)

    HCIO4 is the conjugate acid of H3O+

  31. Ionic product of water increases when _______.

    (a)

    Pressure decreases

    (b)

    H+ ions are added

    (c)

    OH- ions are added

    (d)

    temperature increases

  32. When sodium acetate is added to acetic acid, the degree of ionisation of acetic acid _______.

    (a)

    increases

    (b)

    decreases

    (c)

    dose not change

    (d)

    becomes zero

  33. A drop of hydrochloric acid is added to pure water, its pH _____.

    (a)

    increases

    (b)

    decreases

    (c)

    increases and then decreases

    (d)

    resist the change in pH and so remains unaltered

  34. Which among the following is the strongest reducing agent?

    (a)

    F2

    (b)

    Cl2

    (c)

    Zn

    (d)

    Li

  35. Debye, Huckel and Onsager equation for strong electrolytes is λc = λ (A + Bλ\(\sqrt C\)The slope value is ______.

    (a)

    λ

    (b)

    (A + Bλ

    (c)

    A

    (d)

    \(\sqrt C\)

  36. The quantity of charge required to obtain 1 mole of aluminum from Al2O3 is ______.

    (a)

    2F

    (b)

    3F

    (c)

    6F

    (d)

    12F

  37. Low molar conductivity at high concentration is due to _______.

    (a)

    High attractive force between oppositely charged ions

    (b)

    Viscous drag due to greater solvation

    (c)

    Both High attractive force between oppositely charged ions and Viscous drag due to greater solvation

    (d)

    Neither High attractive force between oppositely charged ions and Viscous drag due to greater solvation

  38. Which among the following does not affect adsorption?

    (a)

    surface area of the adsorbent

    (b)

    catalyst

    (c)

    temperature

    (d)

    pressure

  39. The multilayer adsorption of gases on solids take place in _______.

    (a)

    physical adsorption

    (b)

    chemisorption

    (c)

    sols

    (d)

    active centres

  40. For W/O emulsion, the principle emulsifying agent is _______.

    (a)

    proteins

    (b)

    synthetic soaps

    (c)

    lampblack

    (d)

    gums

  41. The oxidation of sodium sulphite by air is retarded by _______.

    (a)

    MnO2

    (b)

    H2S

    (c)

    Alcohol

    (d)

    AS2O3

  42. An example of Gel is_______.

    (a)

    sharing cream

    (b)

    paints

    (c)

    butter

    (d)

    whippedcream

  43. The colloid used for stomach disorder is_______.

    (a)

    colloidal silver

    (b)

    colloidal antimony

    (c)

    colloidal gold

    (d)

    milk of magnesia

  44. Which is optically active?

    (a)

    n-butyl alcohol

    (b)

    isobutyl alcohol

    (c)

    2-butanol

    (d)

    t-butyl alcohol

  45. Predict the structure of propane-1,2 diol ______.

    (a)

    CH2 (OH) - CH2CH2OH

    (b)

    HOCH2 - CH2OH

    (c)

    CH3CH (OH) CH2OH

    (d)

    None of these

  46. Glycerol when heated with cone. H2SO4 gives ______.

    (a)

    allyl alcohol

    (b)

    propyl alcohol

    (c)

    acrolein

    (d)

    propylene

  47. The boiling point of ethyl alcohol should be less than that of _______.

    (a)

    propane

    (b)

    formic acid

    (c)

    dimethyl ether

    (d)

    none of the above

  48. The alcohol obtained by the hydrolysis of oils and fats is _______.

    (a)

    pentanol

    (b)

    propanol

    (c)

    glycerol

    (d)

    glycol

  49. The ultimate product obtained when glycerol reacts with oxalic acid at 533K is ________.

    (a)

    formic acid

    (b)

    glycerol oxalate

    (c)

    allyl alcohol

    (d)

    acrolein

  50. Oxidation of glycerol with bismuth nitrate gives ________.

    (a)

    meso-oxalic acid

    (b)

    glyceric acid

    (c)

    tartronic acid

    (d)

    both (b) and (c)

  51. According to Lewis concept of acids and bases, ethers are _______.

    (a)

    neutral

    (b)

    acidic

    (c)

    basic

    (d)

    amphoteric

  52. Metamerism is exhibited by _______.

    (a)

    hydrocarbon

    (b)

    nitro compounds

    (c)

    mineral acid

    (d)

    ether

  53. The number of possible isomers for molecular formula C3H8O is _______.

    (a)

    2

    (b)

    3

    (c)

    7

    (d)

    4

  54. On heating, peroxides are ________.

    (a)

    stable

    (b)

    unstable

    (c)

    decomposes violently

    (d)

    both (b) and (c)

  55. Methyl ketones are usually characterised by _______.

    (a)

    the Fehling's solution

    (b)

    the iodoform test

    (c)

    the Schiff's test

    (d)

    the Tollen's reagent

  56. The high boiling points of carboxylic acids is due to _______.

    (a)

    weak Vanderwaal's forces

    (b)

    intermolecular hydrogen bonding

    (c)

    intramolecular hydrogen bonding.

    (d)

    delocalisation of π electrons

  57. Aldol is _________.

    (a)

    2-hydroxy butanol

    (b)

    3 -hydroxy butanol

    (c)

    3- hydroxy butanal

    (d)

    2 -hydroxy butanal

  58. Glucose reacts with acetic anhydride in the presence of pyridine to give

    (a)

    monoacetate

    (b)

    diacetate

    (c)

    penta acetate

    (d)

    no reaction

  59. On hydrolysis, which one of the following disaccharide will give a ketose and an aldose?

    (a)

    Maltose

    (b)

    Sucrose

    (c)

    Lactose

    (d)

    All the above

  60. Pyridoxine is__________

    (a)

    vitamin B6

    (b)

    vitamin B7

    (c)

    vitamin B9

    (d)

    vitamin B5

  61. The properties of protein are determined by___________

    (a)

    nature of the amino acids

    (b)

    the position of NH2 group

    (c)

    the position of COOH group

    (d)

    all

  62. The helical structure of protein is stabilised by_________

    (a)

    peptide bonds

    (b)

    disulphide bonds

    (c)

    hydrogen bonds

    (d)

    Vanderwaals inter action

  63. The class of drugs used for the treatment of stress is _______

    (a)

    antihistamine

    (b)

    tranquilizens

    (c)

    antimicrobials

    (d)

    aminoglycosides

  64. _______ is used mainly as preservative for the preparation of pickles.

    (a)

    Sodium meta bisulphite

    (b)

    Potassiummaeta bisulphite

    (c)

    Benzoic acid

    (d)

    Acetic acid

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