New ! Chemistry MCQ Practise Tests



12th Standard Chemistry Important 1 Mark Questions

12th Standard

    Reg.No. :
  •  
  •  
  •  
  •  
  •  
  •  

Chemistry

Time : 01:00:00 Hrs
Total Marks : 50

    Answer all the following questions.

    50 x 1 = 50
  1. Which one of the following reaction represents calcinations?

    (a)

    \(2Zn+{ O }_{ 2 }\rightarrow 2ZnO\)

    (b)

    \(2ZnS+3O_{ 2 }\rightarrow 2ZnO+2SO_{ 2 }\)

    (c)

    \(MgCO_{ 3 }\rightarrow MgO+CO_{ 2 }\)

    (d)

    Both (a) and (c)

  2. Zinc is obtained from ZnO by________.

    (a)

    Carbon reduction

    (b)

    Reduction using silver

    (c)

    Electrochemical process

    (d)

    Acid leaching

  3. Which of the following is not true with respect to Ellingham diagram?

    (a)

    Free energy changes follow a straight line. Deviation occurs when there is a phase change.

    (b)

    The graph for the formation of CO2 is a straight line almost parallel to free energy axis.

    (c)

    Negative slope of CO shows that it becomes more stable with increase in temperature.

    (d)

    Positive slope of metal oxides shows that their stabilities decrease with increase in temperature.

  4. In diborane, the number of electrons that accounts for banana bonds is ________.

    (a)

    six

    (b)

    two

    (c)

    four

    (d)

    three

  5. The repeating unit in silicone is_______.

    (a)

    SiO2

    (b)

    (c)

    (d)

  6. The compound that is used in nuclear reactors as protective shields and control rods is _________.

    (a)

    Metal borides

    (b)

    metal oxides

    (c)

    Metal carbonates

    (d)

    metal carbide

  7. An element belongs to group 15 and 3rd period of the periodic table, its electronic configuration would be_______.

    (a)

    1s2 2s2 2p4

    (b)

    1s2 2s2 2p3

    (c)

    1s2 2s2 2p6 3s2 3p2

    (d)

    1s2 2s2 2p6 3s2 3p3

  8. Among the following the correct order of acidity is ________.

    (a)

    HClO2 < HClO < HClO3 < HClO4

    (b)

    HClO4 < HClO2 < HClO < HClO3

    (c)

    HClO3 < HClO4 < HClO2 < HClO

    (d)

    HClO < HClO2 < HClO3 < HClO4

  9. Among the transition metals of 3d series, the one that has highest negative \(\left( \frac { M^{ 2+ } }{ M } \right) \) standard electrode potential is _______.

    (a)

    Ti

    (b)

    Cu

    (c)

    Mn

    (d)

    Zn

  10. How many moles of I2 are liberated when 1 mole of potassium dichromate react with potassium iodide?

    (a)

    1

    (b)

    2

    (c)

    3

    (d)

    4

  11. Which one of the following is not correct?

    (a)

    La(OH)3 is less basic than Lu(OH)3

    (b)

    In lanthanoid series ionic radius of Ln3+ ions decreases

    (c)

    La is actually an element of transition metal series rather than lanthanide series

    (d)

    Atomic radii of Zr and Hf are same because of lanthanide contract

  12. As per IUPAC guidelines, the name of the complex [Co(en)2(ONO)Cl]Cl is _______.

    (a)

    chlorobisethylenediaminenitritocobalt(III) chloride

    (b)

    chloridobis(ethane-1, 2-diamine)nitro  K-Ocobaltate(III) chloride

    (c)

    chloridobis(ethane-1, 2-diammine)nitrito K-Ocobalt(II) chloride

    (d)

    chloridobis(ethane-1, 2-diamine)nitrito K-O cobalt(III) chloride

  13. A complex in which the oxidation number of the metal is zero is_______.

    (a)

    K4[Fe(CN)6]

    (b)

    [Fe(CN)3(NH3)3]

    (c)

    [Fe(CO)5]

    (d)

    both (b) and (c)

  14. In calcium fluoride, having the flurite structure the coordination number of Ca2+ ion and F- Ion are ________.

    (a)

    4 and 2

    (b)

    6 and 6

    (c)

    8 and 4

    (d)

    4 and 8

  15. If ‘a’ is the length of the side of the cube, the distance between the body centered atom and one corner atom in the cube will be_________.

    (a)

    \(\left( \cfrac { 2 }{ \sqrt { 3 } } \right) a\)

    (b)

    \(\left( \cfrac { 4 }{ \sqrt { 3 } } \right) a\)

    (c)

    \(\left( \cfrac { \sqrt { 3 } }{ 4 } \right) a\)

    (d)

    \(\left( \cfrac { \sqrt { 3 } }{ 2 } \right) a\)

  16. Among the following graphs showing variation of rate constant with temperature (T) for a reaction, the one that exhibits Arrhenius behavior over the entire temperature range is _______.

    (a)

    (b)

    (c)

    (d)

    both (b) and (c)

  17. For the reaction, 2NH3 ⟶ N2 + 3H2, if \(\frac { -d[NH_{ 3 }] }{ dt } \) = k1[NH3], \(\frac { d[N_{ 2 }] }{ dt } =k_{ 2 }[NH_{ 3 }],\frac { d[{ H }_{ 2 }] }{ dt } \)= k3[NH3] then the relation between k1, k2 and k3 is _________.

    (a)

    k= k= k3

    (b)

    k= 3k= 2k3

    (c)

    1.5k= 3k= k3

    (d)

    2k= k= 3k3

  18. In a first order reaction x ⟶ y; if k is the rate constant and the initial concentration of the reactant x is 0.1M, then, the half life is_____.

    (a)

    \(\left( \frac { \log2 }{ k } \right) \)

    (b)

    \(\left( \frac { 0.693 }{ (0.1)k } \right) \)

    (c)

    \(\left( \frac { In2 }{ k } \right) \)

    (d)

    none of these

  19. The solubility of BaSO4 in water is 2.42 × 10-3gL-1 at 298K. The value of its solubility product(Ksp) will be (Given molar mass of BaSO4 =233g mol-1)

    (a)

    1.08 × 10-14mol2L-2

    (b)

    1.08 × 10-12mol2L-2

    (c)

    1.08 × 10-10mol2L-2

    (d)

    1.08 × 10-8mol2L-2

  20. Which of the following relation is correct for degree of hydrolysis of ammonium acetate?

    (a)

    \(h=\sqrt { \frac { { K }_{ h } }{ C } } \)

    (b)

    \(h=\sqrt { \frac { { K }_{ a } }{ K_b } } \)

    (c)

    \(h=\sqrt { \frac { { K }_{ w } }{ { K }_{ a }.{ K }_{ b } } } \)

    (d)

    \(h=\sqrt { \frac { { { K }_{ a }.{ K }_{ b } } }{ { K }_{ w } } } \)

  21. The button cell used is watches function as follows
    Zn (s) + Ag2O (s) + H2O (l) ⇌ 2Ag (s) + Zn2+ (aq) + 2OH-(aq) the half cell potentials are Ag2O (s) + H2O (l) + 2e- → 2Ag (s) + 2OH- (aq) E= 34V and Zn (s) → Zn2+ (aq) + 2e E0 = 0.76V . The cell potential will be_______.

    (a)

    0.84V

    (b)

    1.34V

    (c)

    1.10V

    (d)

    0.42V

  22. During electrolysis of molten sodium chloride, the time required to produce 0.1mole of chlorine gas using a current of 3A is _____.

    (a)

    55 minutes

    (b)

    107.2 minutes

    (c)

    220 minutes

    (d)

    330 minutes

  23. Consider the change in oxidation state of Bromine corresponding to different emf values as shown in the diagram below:
    \({ BrO }_{ 4 }^{ - }\overset { 1.82V }{ \longrightarrow } { BrO }_{ 3 }^{ - }\overset { 1.5V }{ \longrightarrow } HBrO\overset { 1.595v }{ \longrightarrow } { Br }_{ 2 }\overset { 1.0652V }{ \longrightarrow } Br^{ - }\)
    Then the species undergoing disproportional is

    (a)

    Br2

    (b)

    BrO4-

    (c)

    BrO-3

    (d)

    HBrO

  24. Hair cream is _____.

    (a)

    gel

    (b)

    emulsion

    (c)

    solid sol

    (d)

    sol.

  25. Collodion is a 4% solution of which one of the following compounds in alcohol – ether mixture?

    (a)

    Nitroglycerine

    (b)

    Cellulose acetate

    (c)

    Glycoldinitrate

    (d)

    Nitrocellulose

  26. On which of the following properties does the coagulating power of an ion depend?

    (a)

    Both magnitude and sign of the charge on the ion.

    (b)

    Size of the ion alone

    (c)

    the magnitude of the charge on the ion alone

    (d)

    the sign of charge on the ion alone.

  27. The X is _______.

    (a)

    (b)

    (c)

    (d)

    None of these

  28. on treatment with Con H2SO4, predominately gives______.

    (a)

    (b)

    (c)

    (d)

  29. On reacting with neutral ferric chloride, phenol gives  ______.

    (a)

    red colour

    (b)

    violet colour

    (c)

    dark green colour

    (d)

    no colouration.

  30. Predict the product Z in the following series of reactions Ethanoic acid \(\overset { { PCI }_{ 5 } }{ \longrightarrow } X\overset { { C }_{ 6 }{ H }_{ 6 } }{ \underset { Anhydrous \ AlCI }-_{3}{ \longrightarrow } } Y\overset { 1){ CH }_{ 3 }MgBr }{ \underset { II){ H }_{ 3 }{ O }^{ + } }{ \longrightarrow } } Z.\)

    (a)

    (CH3)2 C(OH)C6H5

    (b)

    CH3CH(OH)C6H5

    (c)

    CH3CH(OH)CH2- CH3

    (d)

  31. The IUPAC name of 

    (a)

    but – 3- enoicacid

    (b)

    but – 1- ene-4-oic acid

    (c)

    but – 2- ene-1-oic acid

    (d)

    but -3-ene-1-oicacid

  32. In which of the following reactions new carbon – carbon bond is not formed?

    (a)

    Aldol condensation

    (b)

    Friedel craft reaction

    (c)

    Kolbe’s reaction

    (d)

    Wolf kishner reduction

  33. CH3CH2 Br \(\overset { aqNaOH }{ \underset { \Delta }{ \longrightarrow } } A\overset { { KMnO }_{ 4 }{ /H }^{ + } }{ \underset { \Delta }{ \longrightarrow } } B\overset { { NH }_{ 3 } }{ \underset { \Delta }{ \longrightarrow } } C\overset { { Br }_{ 2 }/NaOH }{ \longrightarrow } D\)  D' is________.

    (a)

    bromomethane

    (b)

    α - bromo sodium acetate

    (c)

    methanamine

    (d)

    acetamide

  34.  _______.

    (a)

    H3PO2 and H2O

    (b)

    H+/H2O

    (c)

    HgSO4/H2SO4

    (d)

    Cu2Cl2

  35. Identify X in the sequence give below

    (a)

    (b)

    (c)

    (d)

  36. The correct statement regarding RNA and DNA respectively is ______.

    (a)

    the sugar component in RNA is an arabinos and the sugar component in DNA is ribose

    (b)

    the sugar component in RNA is 2’-deoxyribose and the sugar component in DNA is arabinose

    (c)

    the sugar component in RNA is an arabinose and the sugar component in DNA is 2’-deoxyribose

    (d)

    the sugar component in RNA is ribose and the sugar component in DNA is 2’-deoxyribose

  37. Which one of the following structures represents nylon 6,6 polymer?

    (a)

    (b)

    (c)

    (d)

  38. Which is the monomer of neoprene in the following?

    (a)

    (b)

    \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{C} \equiv \mathrm{CH}\)

    (c)

    \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CH}=\mathrm{CH}_{2}\)

    (d)

  39. Among the following, one does not belong to calcination, Pick the odd one out.

    (a)

    \({ PBCO }_{ 3 }\overset { \Delta }{ \longrightarrow } PBO+{ CO }_{ 2 }\uparrow \)

    (b)

    \({ CaCo }_{ 3 }\overset { \Delta }{ \longrightarrow } Cao+{ CO }_{ 2 }\uparrow \)

    (c)

    \(PbS{ O }_{ 3 }\overset { \Delta }{ \rightarrow } PbO+{ 2SO }_{ 2 }\uparrow \)

    (d)

    \({ ZnCO }_{ 3 }\overset { \Delta }{ \rightarrow } ZnO+{ CO }_{ 2 }\uparrow \)

  40. SiO44- ion has ____ geometry.

    (a)

    Triangular

    (b)

    Tetrahedral

    (c)

    Linear

    (d)

    Pentagonal bipyramidal

  41. The C60 molecule is called as_________ because of its structure.

    (a)

    buck minster fullerens

    (b)

    bucky balls

    (c)

    diamond

    (d)

    both (a) & (b)

  42. Pick the wrong one among the following

    (a)

    F2 - Yellow

    (b)

    Br2 - Red

    (c)

    Cl2 - Colourless

    (d)

    I2- Violet

  43. The general electronic configuration of 4f series of elements can be written as ________.

    (a)

    [Xe]4f2-14 5d0-46s2

    (b)

    [Xe]4f2-145d0-46s1

    (c)

    [Xe] 4f1-14506s1

    (d)

    [Xe]4f2-145d0-46s1

  44. Among the following complexes the one which shows zero crystal field stabilisation energy is _______.

    (a)

    [Mn(H2O)6]3+

    (b)

    [Fe(H2O)6]3+

    (c)

    [CO(H2O)6]2+

    (d)

    [CO(H2O)6]3+

  45. Identify, the geometrical isomer of platinum complex with the ligands NH& Cl

    Choose the correct option

    (a)

    i & ii

    (b)

    ii & iii

    (c)

    i & iii

    (d)

    ii & iv

  46. The empty space between the shaded balls and hollow balls as shown in the diagram is called, _______.

    (a)

    Hexagonal void

    (b)

    Octahedral void

    (c)

    Tetrahedral void

    (d)

    Double triangular void

  47. (a)

    It is a 2 steps reaction, step 1 is slower than step 2

    (b)

    It is a 2 steps reaction, step 2 is slower than step 1.

    (c)

    Single step reaction where B is a activated complex

    (d)

    Single step reaction in which B is a reaction intermediate.

  48. Concentration is expressed in?

    (a)

    \(\frac { number\ of\ moles/litre }{ time\ in\ sec } \)

    (b)

    \(\frac { time\ in\ sec }{ number\ of\ moles/litre } \)

    (c)

    \(\frac { number\ of\ moles/litre }{ volume } \)

    (d)

    \(\frac { volume }{ number\ of\ moles/litre } \)

  49. The relationship between degree of dissociation of a weak acid and its dissociation constant in a very dilute solution is _______.

    (a)

    Ka = α2C

    (b)

    Ka\(\frac{α^2C}{(1+α)}\)

    (c)

    Ka\(\frac{α^2}{(1+α)C}\)

    (d)

    Ka\(\frac{α}{C(1+α)}\)

  50. Using the data given below fmd out the strongest reducing agent ______.
    \({ E }_{ { Cr }_{ 2 }{ O }_{ 7 }^{ 2- } }^{ o }{ Cr }^{ 3+ }=1.33V{ ,E }_{ { Cl }_{ 2 }{ / }{ Cl }^{ - } }^{ o }=1.36V\)
    \({ E }_{ { Mn }O_{ 4 }^{ - } }^{ 0 }/{ Mn }^{ 2+ }=1.51V,{ E }_{ { Cr }^{ 3+ }/Cr }^{ o }=-0.74V\)

    (a)

    Cr

    (b)

    Cr3+

    (c)

    Cl-

    (d)

    Mn2+

*****************************************

Reviews & Comments about 12th Standard Chemistry English Medium - Important 1 Mark MCQ's Question Paper and Answer Key 2022 - 2023

Write your Comment