When concentrated   is added to , a white precipitate forms that is 38.7% ca by mass. write a net ionic equation representing the probable reaction that occurs.

Molecular equation: 

Na2CO3 (aq) + CaCl2 (aq) → CaCO3 (s) + 2 NaCl (aq) 

Ionic equation: 

2 Na⁺ (aq) + CO3²⁻ (aq) + Ca²⁺ (aq) + 2 Cl⁻ (aq) → CaCO3 (s) + 2 Na⁺ (aq) + 2 Cl⁻ (aq) 

Net ionic equation: 

CO3²⁻ (aq) + Ca²⁺ (aq) → CaCO3 (s)