Chemistry 9th Class

Monday, May 24, 2021

MCQs of Chapter # 02 [Chemical combinations] Class IX

 

Chemistry IX

MCQs [Chapter# 02]

i.                     “Mass can neither be created nor be destroyed but it can be converted into one form to another form”. It is:

a.      Law of conservation of mass

b.      Law of constant composition

c.       Law of reciprocal proportion

d.      Law of multiple proportion

 

ii.                   “When two different elements separately combine to the fix mass of the third element, the proportion in which they combined with one another shall be either in the same ratio or simple multiple of it.” It is:

a.       Law of conservation of mass

b.      Law of constant composition

c.      Law of reciprocal proportion

d.      Law of multiple proportion

 

iii.                 “Different samples of the same compound always contain the same elements combined together in the same proportions by mass.” It is:

a.       Law of conservation of mass

b.     Law of constant composition

c.       Law of reciprocal proportion

d.      Law of multiple proportion

 

iv.                 “If two elements combined to form more than one compound the mass of the one element that combine with the fixed mass of the other element are in a ratio of small whole numbers or simple multiple of it.” It is:

a.       Law of conservation of mass

b.      Law of constant composition

c.       Law of reciprocal proportion

d.     Law of multiple proportion

 

v.                   Reaction in which two or more substances join together to form one compound is:

a.       Addition reaction

b.      Combination reaction

c.       Synthesis reaction

d.     All of the above

 

vi.                 Reaction in which a compound breaks into two or more substances is:

a.       Addition reaction

b.      Decomposition reaction

c.       Single displacement reaction

d.     All of the above

 

vii.               In any balanced chemical reaction:

a.      Number of reactant and product should be same

b.      Number of reactant should be greater than product

c.       Number of reactant should be lesser than product

d.      Depend on type of reaction

 

viii.             The atomic mass of oxygen is:

a.       8 amu

b.      12 amu

c.      16 amu

d.      20 amu

 

ix.                 Mass number is denoted by:

a.      A

b.      M

c.       N

d.      Z

 

x.                   The molecular formula of benzene is C6H6, its empirical formula should be:

a.      CH

b.      C2H2

c.       C3H3

d.      C4H4

 

xi.                 The sum of all atoms present in a formula unit of the substance is:

a.       Molar mass

b.      Formula mass

c.       Molecular mass

d.      Atomic mass

 

xii.               1 mole of CO2 =

a.       6.02X1020 atoms

b.      6.02X1021 atoms

c.       6.02X1022 atoms

d.     6.02X1023 atoms

 

xiii.             If sodium has atomic mass 23 and its atomic number is 11, total neutron should be:

a.       10

b.      11

c.      12

d.      13

 

xiv.             What is the atomic number of element 12Mg24?

a.       6

b.     12

c.       18

d.      24

 

xv.               What is the mass number of 17Cl35?

a.       17

b.     35

c.       18

d.      None of these

 

xvi.             Total number of proton in 20Ca40:

a.       20

b.      40

c.       60

d.      0

 

xvii.           Molar mass of the substance is the relative mass expressed in:

a.      gm

b.      amu

c.       Kg

d.      All of the above

 

 

 

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