Question

When pbi2 is added to na2co3 a white precipitate is formed. the white precipitate most likely is?

Answer 1

The reaction between the lead iodide, PbI2 and sodium carbonate, Na2CO3, will form the chemical compounds, sodium iodide and lead carbonate as shown below. 
                                PbI2 + Na2CO3 --> NaI + PbCO3
The white precipitate formed in the reaction is PbCO3. 

Answer 2

Answer: The white precipitate formed is of lead carbonate having formula $PbCO_3$

Explanation:

When lead iodide reacts with sodium carbonate, it leads to the formation of a white colored precipitate of lead carbonate along with sodium iodide.

This reaction is a type of double displacement reaction in which exchange of ions takes place.

The equation for the above reaction follows:

$PbI_2(aq.)+Na_2CO_3(aq.)\rightarrow 2NaI(aq.)+PbCO_3(s)$

Hence, the white precipitate is of lead carbonate.