S130: Chemical Rxns – Precipitation – CaCl2 + Na2CO3 -> CaCO3

Introduction

A simple demonstration of how a precipitate is evidence of a chemical reaction taking place is performed by mixing solutions of calcium chloride and sodium carbonate to form the precipitate calcium carbonate (CaCO3).

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

To Conduct Demonstration

  1. Combine solutions in the beaker or petri dish and stir.

Demo Time: ~5 minute

Safety and Disposal

Wash your hands after demonstration. Calcium chloride is an irritant.

Reference

H.W. Hanna and A. Dittmar; Laboratory Manual for General Chemistry, 4th ed.; Morton Publishing Company, Denver, Colorado. (This demonstration has been altered, the original used barium chloride and potassium chromate, which are toxic. Reference is for original version.)

Acknowledgement:

Laurel Hyde Boni, Kristin Boles