In the. Reaction (Na2co3+CaCl2-->2NaCl+caco3)

The precipitate is :

CaCO3.

You should know the table of solubilities. Here is a simplified version.
http://www.csudh.edu/oliver/chemdata/solrules.htm

To determine the precipitate in the reaction Na2CO3 + CaCl2 ⟶ 2NaCl + CaCO3, we need to examine the solubility rules for common ionic compounds.

The solubility rules are as follows:

1. All Group 1 (alkali metals) and ammonium (NH4⁺) compounds are soluble.
2. Most nitrate (NO3⁻) compounds are soluble.
3. Most chloride (Cl⁻), bromide (Br⁻), and iodide (I⁻) compounds are soluble except when paired with silver (Ag⁺), lead (Pb²⁺), or mercury (Hg₂²⁺) ions.
4. Most sulfate (SO4²⁻) compounds are soluble except when paired with calcium (Ca²⁺), strontium (Sr²⁺), barium (Ba²⁺), lead (Pb²⁺), or silver (Ag⁺) ions.
5. Most carbonate (CO3²⁻) and phosphate (PO4³⁻) compounds are insoluble except when paired with Group 1 (alkali metals) or ammonium (NH4⁺) ions.

In our reaction, Na2CO3 (sodium carbonate) and CaCl2 (calcium chloride) are the reactants.

Na2CO3 is a soluble compound according to the solubility rules, so it dissolves in water.

CaCl2 is also soluble according to the solubility rules, so it also dissolves in water.

When these two solutions are combined, the following reaction occurs:

Na2CO3 + CaCl2 ⟶ 2NaCl + CaCO3

The products of the reaction are 2NaCl (sodium chloride) and CaCO3 (calcium carbonate).

Looking at the solubility rules, we find that sodium chloride is a soluble compound since all sodium (Na⁺) compounds are soluble.

On the other hand, calcium carbonate is insoluble according to the solubility rules since carbonate (CO3²⁻) compounds are generally insoluble except when paired with Group 1 (alkali metals) or ammonium (NH4⁺) ions.

Therefore, the precipitate in the given reaction is CaCO3 (calcium carbonate).

To determine the precipitate in the reaction (Na2CO3 + CaCl2 → 2NaCl + CaCO3), we need to identify the products formed when the reaction occurs.

In this case, sodium carbonate (Na2CO3) and calcium chloride (CaCl2) are the reactants. The reaction will proceed through a double displacement reaction, where the positive ions (Na+ and Ca2+) and negative ions (CO32- and Cl-) switch partners.

The products formed are 2 molecules of sodium chloride (NaCl), which are both soluble in water, and one molecule of calcium carbonate (CaCO3).

To determine if the calcium carbonate is a precipitate, we need to check its solubility in water. Calcium carbonate is insoluble in water, which means that it will form a solid precipitate.

Therefore, the precipitate in the reaction is calcium carbonate (CaCO3).