Consider an electrochemical cell based on the spontaneous reaction 2agcl(s) + zn(s) → 2ag(s) + 2cl– + zn2+. if the zinc ion concentration is kept constant at 1 m, and the chlorine ion concentration is decreased from 1 m to 0.001 m, the cell voltage should:

  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-

if you're asking what comes out, it's steam.

the correct answer would be d. hope this !