What mass of Na2CO3 is required to create 750 mL of an aqueous solution where the concentration of the carbonate (CO3-2) ions is 1.75 M? (assume complete dissociation)

139.11 grams

Explanation:

The molarity (M) is equal to m (moles) /L (liters).

Notice how it is in mL so converting it would be 0.75 L (750*10-3)

Now plug in the information

1.75=m/0.75

m=1.3125

Now m is in moles so convert to grams to get the mass

1.3125 mol Na2CO3 * 105.9888 g Na2CO3 = 139.1103

mark him as !

  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-