Page 1 - 4.HOME ASSIGNMENT-(ATOMICITY& MOLECULAR MASS OF THE COMPOUNDS)
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SAI International School
                                                Subject-Chemistry

                                            Ch-Atoms and Molecules
                         Topic-Atomicity& molecular mass of the compounds

                                               HOME ASSIGNMENT
               OBJECTIVE QUESTIONS
               Q.1      Assertion:  Oxygen gas is a diatomic gas.
                        Reason: The formula of Oxygen molecule is O2.

               Q.2      Assertion: The mass of one molecule of Sodium chloride is 58.5g.
                        Reason: The formula of Sodium chloride molecule is NaCl.
               Q.3      Assertion: Molecular mass of carbon dioxide gas is 44u.
                        Reason: One molecule of Carbon dioxide is 44 times heavier than 1/12th
                        of the mass of one atom of C-12
               Q.4      The molecular mass of CaCO3 is 100 u. (True/False)
               Q.5      The formula unit mass of Potassium chloride is
                        a) 74.5 u
                        b) 80 u
                        c)74.5g
                        d) 39.5 u
               Q.6      The molecular mass of Calcium bicarbonate is

                        a)     172 u
                        b)     162 u
                        c)     182 u
                        d)     192 u
               Q.7         The atomicity of K2Cr2O7 is
                           a)  11
                           b)  12
                           c)  13
                           d)  14
               Q.8      Q.8 The formula of oxide of a metal X is X2O3. What is its atomicity?
                        a)     5
                        b)     7
                        c)     8
                        d)     3


               Subjective:
           S.LNo.  Questions                                                                  Mark     Skill
           Q.1       What is meant by Relative molecular mass of a substance?                 1        R/E

           Q.2       What is formula unit mass of an ionic compound?                          1        R/Av

           Q.3       State two examples in each case and write their chemical                 3        U/Av
                     formulae:
                         a)  Molecules having same kind of atomsonly.
                         b)  Molecules having two different kinds ofatoms.
                         c)  Molecules having three different kinds ofatoms.



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