Để pha 2 lít dung dịch H2SO4 0,1N từ axit đặc 98% (d 1.84g/ml). Cần lấy bao nhiêu ml acid đặc

Cm = Cn/n = 0.1/2 = 0.05 (M)

n = 0.05*2= 0.1 mol

m H2SO4= 0.1*98= 9.8 g

m dd H2SO4= 9.8/ 0.98 =10 g

V= 10/ 1.84 = 5.435 ml

Explanation:

  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-