5. How many moles are in 58.6 L of Nitrogen gas (N.) at STP?

2.6166 moles

Explanation:

stp means: T=273k   p=101.3kpa

R= 8.31(constant)       v=58.6  

using the ideal gas law; pv=nRt

                                        101.3 x 58.6 = n x 8.31 x 273

                                         n= (101.3 x 58.6)\(8.31 x 273)

                                         n= 2.6166moles

  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-

it means there are 3 atoms of oxygen