Friday, May 18, 2012

Law of multiple proportions,Law of reciprocal proportions

Law of multiple proportions :-  laws of multple proportions when two elements combine to form two or more chemical compound and the mass of first elements is fixed ,then mass of other chemical elements bear a simple whole number ratio in all compounds.

Example :- Carbon and oxygen combine to form carbon dioxide and carbon monoxide gas.

     in carbon dioxide     12 part carbon and 32 part oxygen   
&  in carbon monoxide 12 part carbon and 16 part oxygen . 

Here mass of carbon is fixed and mass of oxygen bear a simple ratio  32: 16 
                                                                                                                       or 2:1 to each other 

Law of reciprocal proportions :- The ratio of the masses of two elements A and B which combine separately with  a fixed mass of the third elements C is always bear a simple ratio , when A and B combine directly with each other.

Examples :- 

H and S  combine separately with third elements S to  form H2S 
and SO2 and H and S directly combine to form H2O
 

             in   H2S         2        part H and 16 part S  
and      in SO2        32         part O and 16 part S 
 

                            the ratio of H to O when S is fixed = 2: 32 
       when H and O combine to form H2O
        2 part H combine with 16 part O  hence ratio  = 2: 16
                            simple ratio related to each other 1632   or 1: 2
                                                                hence they are simple multiple of each other 

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