Question

Q28.Write the formula and calculate the molecular massolia) Carbon tetrachloride (b)Ammonium Sulphate (Atomic masses of C=12u, CI=35. N=14 u, H=1u, S=32 u, O=16 u) *​

Answer 1

carbon tetrachloride CCl4

molecular mass

12*1 + 35*4

12 + 140

152

Ammonium sulphate (NH4)2SO4

molecular mass

14*2 + 1*8 + 32*1 + 16*4

132

Answer 2

The formula of the following:

• a) Carbon tetrachloride- CCl4 [C=carbon and Cl=chlorine] The compound is used in fire extinguishers.
• b)Ammonium Sulphate- (NH4)2SO4  [N=nitrogen, H=hydrogen,

                                                                     S= sulphur and O=oxygen]                      

        The compound is used in fertilizers for the alkaline in soils artificially.

The molecular mass of the following:

• a) Carbon tetrachloride- CCl4

            CCl4= {(12×1)+(35×4)}    [Atomic masses of C=12amu, CI=35amu]

         ⇒CCl4={12+140}amu     [amu stands for atomic mass units]

         ⇒CCl4=152amu

• b)Ammonium Sulphate- (NH4)2SO4  

           (NH4)2SO4={((14×1)+(4×1))×2}+32+(16×4) [Atomic masses of N=14 amu,    

                                                                    H=1amu, S=32amu, O=16amu]

       ⇒ (NH4)2SO4={(14+4)×2}+32+64 amu

       ⇒ (NH4)2SO4={18×2}+32+64 amu

       ⇒ (NH4)2SO4=36+32+64 amu

       ⇒ (NH4)2SO4= 132amu                                      

Hence the formulas of a) Carbon tetrachloride is CCl4 and b)Ammonium Sulphate is (NH4)2SO4.

Hence the molecular masses of a) Carbon tetrachloride- CCl4 is 152amu and b) Ammonium Sulphate- (NH4)2SO4 is 132amu.