Asolution contains an unknown mass of dissolved barium ions. when sodium sulfate is added to the solution, a white precipitate forms. the precipitate is filtered and dried and then found to have a mass of 236 mg. what mass of barium was in the original solution? (assume that all of the barium was precipitated out of solution by the reaction.)

0.1388 g

Explanation:

The mass of obtained on precipitation = 236 mg

1 mg = 0.001 g

Thus, Mass of = 0.236 g

Molar mass of = 233.43 g/mol

The formula for the calculation of moles is shown below:

Thus,

Moles of = 0.001011 moles

According to the reaction,

Thus, moles of barium = 0.001011 moles

Molar mass of barium = 137.327 g/mol

Thus, Mass = Moles * Molar mass = 0.001011*137.327 g = 0.1388 g

  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-