5.6 g of an organic compound on burning with excess of oxygen gave 17.6 g of CO2, and 7.2 g of H, O. The
organic compound is :

organic compound is :​ C₄H₈

Explanation: The equation of the reaction of the organic compound burning with excess oxygen gives us the general equation as

C xHy  + 1/2(x+ y/2 )O₂ → xCO₂ + y/2H₂O

We first find the number of moles of CO₂ and H₂O

Number of moles of CO₂= Mass/ molar mass

= 17.6g/ 44g/mol ( 12+ 16 x2)

=0.4 moles

Number of moles of H₂O= Mass/ molar mass

= 7.2g/ 18g/mol ( 1 X 2+ 16)

=0.4 moles

From the reaction , we can see that  

x = 0.4

and  = 0.4  such that y= 0.4 x 2= 0.8

Their ratios become

==

Therefor the organic compound CxHy  = C₄H₈

​  

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-