# Identify a chemical reagent out of these 5 that can be used to distinguish CaCl2 from CaCO3. What is the distinguishing observation?

Lab report question:

$NaCl$
$Na_2CO_3$
$MgSO_4$
$NH_4Cl$
$H_2O$

Identify a chemical reagent out of these 5 that can be used to distinguish $CaCl_2$ from $CaCO_3$. What is the distinguishing observation?

I think it's $Na_2CO_3$ but I'm not completely sure how to answer the question.

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Why do you think it is Na2CO3? Given this is a “homework” question, you should give us the maximum information about your thought process so we can help you… –  F'x Oct 7 '12 at 7:15