If a second brass washer of 0.6003 grams had been dissolved in nitric acid, diluted to 50.00 mL and then its absorbance measured at 0.450, what would be the concentration of Cu(NO₃)₂ in the solution? What would be the mass percent of copper in the second brass washer? Use equation of the line as y=3.1295x+0.0055.

  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-

let that person have a turn to speak : )

d) a person who learns about the world by observing it.

explanation:

scientist are people who discover why and how things are done and made in the world.