A 15.8 g sample contains 3.60 g F, 4.90 g H, and 7.30 g C. What is the percent composition of hydrogen in this sample?

The correct answer is "32%".

Explanation:

The given values:

Weight of H,

= 4.9 g

Weight of sample,

= 15.8 g

Now,

The weight percentage of C will be:

=

By substituting the values, we get

=

=

  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-