5.30 g of Na2CO3 dissolved in 400.0 mL solution.
the molarity
[tex]mv = \frac{grams}{molar \: mass} [/tex]
[tex](x)(0.4000l) [/tex]
[tex] = 5.30g |105.988g \: {mol}^{ - 1} [/tex]
[tex] = 0.12501415m[/tex]
[tex] x = 0.125m[/tex]
therefore, the molarity of 5.30 g of Na2CO3 dissolved in 400.0 mL solution is 0.125m.