Atoms Worksheets





Atoms Worksheets
The atom is a unit of matter which contains dense central nucleus inclosed within a cloud of negatively charged electrons. Atomic nucleus contains positively charged protons and electrically neutral charged neutron.

Some of the Important questions and answers of atoms are given below:-

Worksheet questions:-

1. In chlorine gas, ratio of Cl^35 and Cl^37 is:

(a)    1:3

(b)   3:1

(c)    1:1

(d)   1:4

2. A solution of 10 ML \dfrac{M}{10}FeSO_4 was titrated with KMnO_4 solute in acidic medium. The amount of KMnO_4 used will be:

(a)    5 ML of 0.1 M

(b)   10 ML of o.1 M

(c)    10 ML of 0.5 M

(d)   10 ML of 0.02 M

 

3. Sulphur forms the chlorides S_2Cl_2 and SCl_2. The equivalent mass of sulphur in SCl_2 is:

(a)    8

(b)   16

(c)    64.8

(d)   32

 

4. 19.7 kg of gold was recovered from a smuggler. How many atoms of gold were recovered ?(AU = 197)

(a)    100

(b)   6.02 \times 10^23

(c)    6.02 \times 10^24

(d)   6.02 \times 10^25

 

5. Crystals of which pair are isomorphus:

(a)    ZnSO_4, SnSO_4

(b)   MgSO_4, CaSo_4

(c)    ZnSO_4, MgSO_4

(d)   PbSO_4, NiSO_4

 

6. 74.5 g of a metallic chloride contain 35.5b g of chlorine. The equivalent weight of the metal is:

(a)    19.5

(b)   35.5

(c)    39.0

(d)   78.0

 

7. 1 mol of CH_4 contains:

(a)    6.02 \times 10^23 atoms of H

(b)   4 g atoms of hydrogen

(c)    1.18 \times 10^23 molecules of CH_4

(d)   3.0 g of carbon

 

8. The molecular weight of hydrogen peroxide is 34. What is the unit of molecular weight question:

(a)    Gm

(b)   mol

(c)    g mol^{-1}

(d)   mol g^{-1}

 

9. The prefix atto (a) stands for:

(a)    10^{-12}

(b)   10^{-15}

(c)    10^{-14}

(d)   10^{-18}

 

10. The equivalent weight of an element is 4. Its chloride has V.D. 59.5. then the valency of the element is:

(a)    4

(b)   3

(c)    2

(d)   1

 

11. The density of gas A is three times that of gas B. if the molecular weight of A IS M, the molecular weight of B is:

(a)    3 M

(b)   \sqrt{3M}

(c)    \dfrac{M}{3}

(d)   \dfrac{M}{\sqrt{3}}

 

12. At S.T.P. the density of CCl_4 vapour in g /L will be nearest to :

(a)    6.84

(b)   3.42

(c)    10.26

(d)   4.57

 

13. Which of the following has smallest number of molecules question:

(a)    0.1 mole of CO_2 gas

(b)   11.2 l of CO_2 gas at N.T.P.

(c)    22 g of CO_2

(d)   22.4 \times 10^3 ML of CO_2 gas

 

14. One litre hard water contains 12.00 mg Mg^{2 +}. Milli-equivalents of washing soda required to remove its hardness is:

(a)    1

(b)   12.16

(c)    1 \times 10^{-3}

(d)   12.16 \times {-3}

 

15. When potassium permanganate is titrated against ferrous ammonium sulphate, the equivalent weight of potassium permanganate is:

(a)    Molecular weight / 10

(b)   Molecular weight / 5

(c)    Molecular weight / 2

(d)   Molecular weight

 

16. Ratio of Cp and Cv of gas ‘x’ is 1.4. the number of atoms of the gas ‘s’ present in 11.2 litres of it at N.T.P will be”

(a)    6.02 \times 10^{23}

(b)   1.2 \times 10^{23}

(c)    3.02 \times 10^{23}

(d)   2.02 \times 10^{23}

 

17. What is the weight of oxygen required for the complete combustion of 2.8 kg of ethylene question?

(a)    2.8 kg

(b)   6.4 kg

(c)    9.6 kg

(d)   96 kg

 

18. The number of water molecules in 1 litre of water is:

(a)    18

(b)   18 × 1000

(c)    NA

(d)   5555 NA

 

19. The number of gram molecules of oxygen in 6.02 \times 10^{24} CO molecules is:

(a)    10 gm molecules

(b)   5 gm molecules

(c)    1 gm molecules

(d)   0.5 gm molecules

 

20. Boron has two stable isotopes. ^ {10} B (19 %)  and ^{11} B (81%). The atomic mass that should appear for boron in the periodic table is:

(a)    10.8

(b)   10.2

(c)    11.2

(d)   10.0

 

21. The weight of 1 \times 10^{22} molecules of CuSo_4.5H_2o is:

(a)    41.59 g

(b)   415.9 g

(c)    4.158 g

(d)   None of the these

 

22. The number of oxygen atoms in 4.4 g of Co_2 is approximately:

(a)    1.2 \times 10^{23}

(b)   6\times 10^{2}

(c)    6\times 10^{23}

(d)   12 \times 10^{23}

 

23. The number of moles of BaCo_3 which contains 1.5 moles of oxygen atom is:

(a)    0.5

(b)   1

(c)    3

(d)   6.02 \times 10^{23}

 

24. Two elements X (atomic weight = 75) and Y (atomic weight = 16) combine to give a compound having 75.8 % of X. the formula of the compound is:

(a)    XY

(b)   X_2Y

(c)    X_2Y_2

(d)   X_2Y_3

 

25. The amount of water that should be added to 500 ml of 0.5 N solution of NaOH to give a concentration of 10 mg per ml is:

(a)    100

(b)   200

(c)    250

(d)   500

 

26. 100 ml of 1.0 M HCL are mixed with 75 ml of 1.0 M Na_2CO_3. The resulting solution will be:

(a)    Acidic

(b)   Basic

(c)    Neutral

(d)   Amphoteric

 

27. The law of multiple proportions was proposed by:

(a)    Lavoisier

(b)   Dalton

(c)    Proust

(d)   Gay-Lussac

 

28. 0.115 g of pure sodium metal was dissolved in 500 ml distilled water. The normality of the solution would be [ Na = 23]:

(a)    0.010 N

(b)   0.00115 N

(c)    0.023 N

(d)   0.046 N

 

29. The percentage of P_2O_5 in diammonium hydrogen phosphate (NH_4)_2HPO_4 is:

(a)    23.48

(b)   46.96

(c)    53.78

(d)   71.00

 

30. The total number of protons in 10 g of calcium carbonate is (NO = 6.023 \times 10^{23}):

(a)    1.5057 \times 10^{24}

(b)   2.0478\times 10^{24}

(c)    3.0115\times 10^{24}

(d)   4.0956\times 10^{24}

 

31. How many milliliters (ml) of  1 M H_2SO_4 solution is required to neutralize 10 ml of 1 M NaOH solution?

(a)    2.5 ml

(b)   5.0 ml

(c)    10.0 ml

(d)   20.0 ml

 

32. One litre of gas at STP weighs 1.16 g. it can possibly be:

(a)    C_2H_2

(b)   CO

(c)    O_2

(d)   CH_4

 

33. If the equivalent weight of trivalent metal is 32.7, the molecular weight of its chloride is:

(a)    68.2

(b)   103.7

(c)    204.6

(d)   32.7

 

34. 1.12 ml of gas is produced at S.T.P. by the action of 4.12 mg of alcohol, ROH, with methyl magnesium iodide. The molecular mass of alcohol is:

(a)    16.0

(b)   41.2

(c)    82.4

(d)   156.0

 

35. In the reaction 2 Na_2 S_2 O_2 + I_2 \to Na_2 S_4 O_6 + 2 NaIthe equivalent weight of Na_2 S_2 O_3 (mol. Wt. = M) is equal to:

(a)    M

(b)   M/2

(c)    M/3

(d)   M/4

 

36. The number of significant figure in \dfrac{h}{ 2 \pi} are:

(a)    Three

(b)   Infinite number

(c)    Zero

(d)   One

 

37. The velocity of light is 3.0 \times 10^8 ms^{-1}. The number of significant figure in it is:

(a)    One

(b)   Two

(c)    Nine

(d)   Ten

 

38. Which one of the following is not an element?

(a)    Diamond

(b)   Plastic sulphur

(c)    Silica

(d)   Graphite

 

39. Which one of the following processes results in the formation of  a new chemical compound?

(a)    Dissolving common salt in water

(b)   Sublimation of  NH_4Cl

(c)    Heating platinum rod

(d)   Heating iron rod

 

40. One Fermi is:

(a)     10^{-23} cm

(b)    10^{-15} cm

(c)     10^{-10} cm

(d)    10^{-12} cm

 

41. In the final answer of the expression \dfrac{(29.2- 20.2)(1.79 \times 10^5)}{1.37} the number of significant figures is:

(a)    1

(b)   2

(c)    3

(d)   4

 

42. The simplest formula of compound containing 50% of element X (atomic mass 10) and 50% of element Y (atomic mass 20) is:

(a)    XY

(b)   X_2Y

(c)    X_2Y_2

(d)   X_2Y_3

 

43. The hydrogen phosphate of certain metal has formula MHPO_4 . the formula of metal chloride would be:

(a)    MCL

(b)   MCL_2

(c)    M_2CL_2

(d)   MCL_3

 

44. A 5 molar solution of  H_2 SO_4 is diluted from 1 litre to a volume of 10 litres, the normality of the solution will be:

(a)    1 N

(b)   0.1 N

(c)    5 N

(d)   0.5 N

 

45. If NA  is Avogadro’s number then number of valence electrons in 4.2 g of nitride ions N^{3-} is:

(a)    2.4 NA

(b)   4.2 NA

(c)    1.6 NA

(d)   3.2 NA

 

46. A metal oxide has the formula Z_2O_3. It can be reduced by hydrogen to give free metal and water. 0.1596 g of the metal oxide requires 6 mg of hydrogen for complete reduction. The atomic weight of the metal is:

(a)    27.9

(b)   159.6

(c)    79.8

(d)   55.8

 

47. The number of electrons in a mole of hydrogen is:

(a)    6.02 \times 10^{23}

(b)   12.046 \times 10^{23}

(c)    3.0115\times 10^{23}

(d)   None of them

 

48. In the given numbers 161 cm, 0.161 cm 0.0161 cm the number of significant figure for the three numbers is:

(a)    3, 3, 4

(b)   3, 3, 3

(c)    3, 4, 5

(d)   3, 4, 4

 

49. A gm of the metal give B gm of its oxide. So the equivalent mass of the metal is:

(a)    \dfrac{B + A}{A} \times 8

(b)   \dfrac{B- A}{A} \times 8

(c)    \dfrac{B + A}{A} \times 6

(d)   \dfrac{A}{B- A} \times 8

 

50. Kg m^{-1} s^{-2} is the unit of:

(a)    Velocity

(b)   Pressure

(c)    Momentum

(d)   Acceleration

 

51. Dimensions of pressure are same as that of:

(a)    Energy

(b)   Force

(c)    Energy per unit volume

(d)   Force per unit volume

 

52. Equivalent weight of crystalline oxalic acid is:

(a)    92

(b)   63

(c)    45

(d)   53

 

53. The vapour density of a gas is 11.2. the volume occupied by 11.2 g of the gas at N.T.P. will be:

(a)    11.2 L

(b)   22.4 L

(c)    1 L

(d)   24.8 L

 

54. The amount of zinc required to produce 224 ml of H2 at S.T.P.  on treatment with dil. \, H_2SO_4 will be:

(a)    0.65 g

(b)   6.5 g

(c)    0.065 g

(d)   65 g

 

55. 1 amu is equal to:

(a)    \dfrac{1}{12} \, \, of \, \, C -12

(b)   \dfrac{1}{14} of O – 16

(c)    1 g of H2

(d)   1.66 \times 10^{-23}

 

56. 10 g of CaCO_3 gives on strong heating CO_2. It gives quick lime (in grams):

(a)    5.2 g

(b)   5.6 g

(c)    4.4 g

(d)   4 g

 

57. Number of moles of KMnO_4 required to oxidize one mole of Fe(C_2 O_4) in acidic medium is:

(a)    0.6

(b)   0.167

(c)    0.2

(d)   0.4

 

58. The maximum amount of BaSO_4 precipitated on mixing equal volumes of  BaCl_2 (0.5 M) with H_2S O_4 (1 M) will correspond to:

(a)    0.5 M

(b)   1.2 M

(c)    5.0 M

(d)   2.0 M

 

59. 50 ml 10  N H_2 SO_4 25 ml 12 N  HCL and 40 ml 5 NHNO_3 were mixed together and the volume of the mixture was made 1000 ml by adding water. The normality of the resultant solution will be:

(a)    1 N

(b)   3 N

(c)    2 N

(d)   4 N

 

60. Given the numbers : 161 cm, 0.161 cm, 0.0161 cm. the number of significant figures for the three numbers are:

(a)    3, 4 and 5 respectively

(b)   3, 3 and 3 respectively

(c)    3, 3 and 4 respectively

(d)   3, 4 and 4 respectively

 

61. The number of molecules in 16 g of methane is:

(a)    3.0 \times 10^{23}

(b)   6.02 \times 10^{23}

(c)    \dfrac{16}{3.0} \times 10^{23}

(d)   \dfrac{16}{6.02} \times 10^{23}

 

62. Hemoglobin contains 0.33% of iron by weight. The molecular weight of hemoglobin is approximately 67200. The number of iron atoms (at. Wt. of Fe = 56) present in one molecule of hemoglobin  is:

(a)    6

(b)   2

(c)    4

(d)   3

 

63. A 100 ml solution of 0.1 N HCl was titrated with 0.2 N NaOH solution. The titration was discontinued after adding 30 ml of NaOH solution. The remaining titration was completed by adding 0.25 N KOH solution. The volume of KOH required for completing the titration is:

(a)    32 ml

(b)   70 ml

(c)    35 ml

(d)   16 ml

 

64. The number of atom in 4.25 g of NH_3 is approximately:

(a)    1 \times 10^{23}

(b)   4 \times 10^{23}

(c)    4 \times 10^{23}

(d)   6 \times 10^{23}

 

65. One mole of calcium phosphide on reaction with excess of water gives:

(a)    Two moles of phosphoric acid

(b)   One mole of phosphine

(c)    Two moles of phosphine

(d)   One mole of phosphorus pentoxide

 

66. Number of g of oxygen in 32.2 g Na_2 SO_4. 10 H_2 O is:

(a)    20. 8

(b)   22.4

(c)    2.24

(d)   2.08

 

67. Assuming fully decomposed, the volume of CO_2 released at S.T.P. on heating 9.85 g of BaCO_3. (atomic mass, Ba = 137) will be:

(a)    0.84 L

(b)   2.24 L

(c)    4.06 L

(d)   1.12 L

 

68. A compound contains of three elements A, B and C. if the oxidation number of A is + 2, B is + 5 and that of C is – 2, the possible formula of the compound is:

(a)     A_3 (BC_4)_2

(b)    A_3 (B_4C)_2

(c)     A_2 (BC_3)_2

(d)    ABC_2

 

69. The specific heat of a metal is 0.16, approximate atomic weight would be:

(a)    32

(b)   64

(c)    40

(d)   16

 

70. Which of the following contains maximum number of atoms?

(a)    6.023 \times 10^{21} molecules of CO_2

(b)   22.4 L of CO_2 at STP

(c)    0.46 g of CO_2

(d)   0.22 g of CO_2

 

71. The weight of a molecule of the compound C_{60}H_{122} is:

(a)    1.4 \times 10^{-12} g

(b)   5.025 \times 10^{23} g

(c)    1.4 \times 10^{-12} g

(d)   1.4 \times 10^{-12} g

 

72. The number of water molecules present in a drop of water (volume 0.0018) at room temperature is:

(a)    6.023 \times 10^{19}

(b)   1.094 \times 10^{18}

(c)    4.84\times 10^{17}

(d)   6.023 \times 10^{23}

 

73. Which of the following halogen can be purified by sublimation?

(a)    F_2

(b)   Cl_2

(c)    Br_2

(d)   I_2

 

74. The percentage of Se in peroxide anhydrous enzyme is 0.5% by weight (atomic weight = 78.4). then minimum molecular weight of anhydrous enzyme is:

(a)    1.568 \times 10^{14}

(b)   1.568 \times 10^{3}

(c)    15.68

(d)   3.136 \times 10^4

 

75. 7. 5 grams of a gas occupy 5.6 L volume at S.T.P. then gas is:

(a)    NO

(b)   CO

(c)    CO_2

(d)   NO_2

 

76. The percentage of nitrogen in urea is about:

(a)    46

(b)   18

(c)    85

(d)   28

 

77. In a hydrocarbon, the mass ratio of hydrogen to carbon is 1 : 3. The empirical formula of the hydrocarbon is:

(a)    CH

(b)   CH_2

(c)    C_2H_3

(d)   CH_3

(e)   CH_4

 

78. How much of NaOH is required to neutralise 1500 cm^3 of 0.1 N HCl ?(Na = 23)

(a)    40 g

(b)   4 g

(c)    6 g

(d)   60 g

 

79. The set of numerical cofficients that balances the equation:

K_2 CrO_4 + HCl \to K_2 Cr_2 O_7 + KCl + H_2 O is:

(a)    1, 1, 2, 2, 1

(b)   2, 2, 1, 1, 1

(c)    2, 1, 1, 2, 1

(d)   2, 2, 1, 2, 1

(e)   2, 2, 2, 1, 1

 

80. The modern atomic weight scale is based on:

(a)    C^{12}

(b)   O^{16}

(c)    H^1

(d)   C^{13}

 

81. A mixture o0f sand and iodine can be separated by:

(a)    Distillation

(b)   Sublimation

(c)    Crystallization

(d)   Fractionation

 

82. The prefix 10^{18} is:

(a)    Giga

(b)   Exa

(c)    Kilo

(d)   Nano

(e)   Mega

 

83. Irrespectively of the source, pure sample of water always yields 88.89% mass of oxygen and 11.11% mass of hydrogen. This is explained by the law of:

(a)    Conservation of mass

(b)   Constant composition

(c)    Multiple proportion

(d)   Constant volume

 

84. Which has maximum molecules?

(a)    7 g N_2

(b)   2 g H_2

(c)    16 g NO_2

(d)   16 g O_2

 

85. Number of atoms in 558.5 g Fe (at. Wt. of Fe= 55.85 g \, mole^{-1} ) is:

(a)    Twice that in 60 g carbon

(b)   6.023 \times 10^{22}

(c)    Half than in 8 g He

(d)   558.5 \times 6.023 \times 10^{23}

 

86. 30 g of Magnesium and 30 g of Oxygen are reacted, then the residual mixture contains:

(a)    60 g of Magnesium oxide only

(b)   40 g of Magnesium oxide and 20 g of Oxygen

(c)    45 g of Magnesium oxide and 15 g of Oxygen

(d)   50 g of Magnesium oxide and 10g of Oxygen

 

87. 3 g of an oxide of a metal is converted to chloride completely and it yielded 5 g of chloride. The equivalent weight of the metal is:

(a)    33.25

(b)   3.325

(c)    12

(d)   20

 

88. In order to prepare one litre normal solution of KMnO_4, how many grams of KMnO_4 are required, if the solution is to be used in acidic medium for oxidation?

(a)    158 g

(b)   31.6 g

(c)    62.0 g

(d)   79.0 g

 

89. 30 ml of an acid is neutralized by 15 ml of 0.2 N alkali. The strength of the acid is:

(a)    0.1 N

(b)   0.3 N

(c)    0.3 N

(d)   0.4 N

 

90. A metallic oxide contains 60% of the metal. The equivalent weight of the metal is:

(a)    12

(b)   40

(c)    24

(d)   48

 

91. The maximum number of molecules is present in:

(a)    15 L of _2 gas at S.T.P.

(b)   5 L of N_2 gas at S.T.P.

(c)    0.5 g of H_2

(d)   10 g of O_2 gas

 

92. Avogadro’s number is the number of molecules present in:

(a)    1 litre of molecule

(b)   1 g of molecule

(c)    Gram molecular mass

(d)   1 g atom

 

93. The total number of protons in 10 g of calcium carbonate is ( No = 6.023 \times 10^{23}:

(a)    3.01 \times 10^{24}

(b)   4.06 \times 10^{24}

(c)    2.01 \times 10^{24}

(d)   3.01 \times 10^{24}

 

94. One mole of CH_4 contains:

(a)    4.0 gm atoms of hydrogen

(b)   3.0 g atoms of carbon

(c)    6.02 \times 10^{23} atoms of hydrogen

(d)   1.18 \times 10^{23} molecules of  CH_4

 

95.  MnO^{-2}_4 (1 mole) in neutral aqueous medium disproportionate

(a)    \dfrac{1}{3} mole of MnO_4^{-} and \dfrac{2}{3} mole of MnO+2

(b)   \dfrac{2}{3} mole of MnO_4^{-} and \dfrac{1}{3} mole of MnO+2

(c)    \dfrac{2}{3} mole of Mn_2O_7 and \dfrac{1}{3} mole of MnO+2

(d)   \dfrac{1}{3} mole of Mn_2O_7 and \dfrac{2}{3} mole of MnO+2

 

96. The total number of atoms represented by the compound CuSO_4.5H_2O is:

(a)    27

(b)   21

(c)    5

(d)   8

 

97. The equivalent weight of H_3PO_4 in the reaction:

NaOH + H_3PO_4 \to NaH_2PO_4 + H_2 O is:

(a)    59

(b)   26

(c)    98

(d)   49

 

98. Molarity of 0.2 N H_2SO_4 is:

(a)    0.2

(b)   0.1

(c)    0.3

(d)   0.6

 

Worksheet Answers:-

1. (b)           2. (d)            3. (d)              4. (d)             5. (c)

6. (c)            7. (b)            8. (c)               9. (d)           10. (b)

11. (c)         12. (a)            13. (a)            14. (a)           15. (b)

16. (a)         17. (c)             18. (d)            19. (b)          20. (a)

21. (c)         22. (a)           23. (a)            24. (d)          25. (d)

26. (b)         27. (b)           28. (a)            29. (c)          30. (c)

31. (d)         32. (a)           33. (c)            34. (c)           35. (a)

36. (b)          37. (a)           38. (c)            39. (d)         40. (a)

41. (b)         42. (b)           43. (b)            44. (a)          45. (a)

46. (d)          47. (b)          48. (d)             49. (d)         50. (c)

51. (c)          52. (b)            53. (a)            54. (a)          55. (a)

56. (b)          57. (a)             58. (a)            59. (a)        60. (b)

61. (b)         62. (c)             63. (d)            64. (b)         65. (c)

66. (b)          67. (d)            68. (a)            69. (c)          70. (b)

71. (a)          72. (a)             73. (d)            74. (a)          75. (a)

76. (a)           77. (e)             78. (c)           79. (d)          80. (a)

81. (a)          82. (b)             83. (b)           84. (b)          85. (a)

86. (b)          87. (a)             88. (b)            89. (a)        90. (a)

91. (a)            92. (c)            93. (a)             94. (a)        95. (b)

96. (b)            97. (c)            98. (b)



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