The atomic masses of 35Cl (75.53 percent) and 37Cl 17 17 (24.47 percent) are 34.968 amu and 36.956 amu, re- spectively. Calculate the average atomic mass of chlorine. The percentages in parentheses denote the relative abundances.

Explanation:

the average atomic mass of chlorine= (34.968 x 0.7553) + ( 36.956 x 0.2447) = 35.4545

Ca % = 100x (5 x 40/502 ) = 39.84 % ( where 502 is molar mass of comp)

P% = 3 x 30.97367 x 100/502 = 18.51 %

O % = (100x13x16)/502 = 41.434

H % = 100-39.84-18.51-41.434 = 0.216 %

% Ca = 100 x40/( 116) = 34.483 %

% Si = 100 x28/116 = 24.14 %

% O = 100-34.483-24.14 = 41.38 %

  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-