I have been trying for a while to determine what products are produced when copper sulfate reacts with sodium bicarbonate at room temperature and standard pressure. However, while I was looking, I found conflicting information concerning what products are formed. Some sources claim that the products are copper hydroxide and sodium sulfate, while other sources state that the products are copper carbonate and sodium sulfate.

I believe the reaction is:

$$\ce{CuSO4 + 2NaHCO3 -> CuCO3 + CO2 + H2O + Na2SO4}$$

Is this correct?

  • 1
    $\begingroup$ It's surprising how one can find quality, directly relevant chemistry videos on YouTube. Look here for what seems to be the exact answer to your question. $\endgroup$ – Nicolau Saker Neto Aug 1 '15 at 16:09

Copper sulfate reacts with sodium bicarbonate reacts to form basic copper carbonate and not copper carbonate due to the great affinity of the $\ce{Cu^2+}$ ion for the hydroxide anion $\ce{OH−}$.

Wikipedia says:

Basic copper carbonate can also be prepared by reacting aqueous solutions of copper(II) sulfate and sodium bicarbonate at ambient conditions. Basic copper carbonate precipitates from the solution, again with release of carbon dioxide:

$$\ce{2 CuSO4 + 4 NaHCO3 → Cu2(OH)2CO3 + 2 Na2SO4 + 3 CO2 + H2O}$$

Here, the "ambient condition" is very important because if we alter the temperature and/or pressure , the reaction will tend to form copper(II) carbonate. In this site, it is mentioned that the ambient temperature to form basic copper carbonate is 60°C.

As for copper(II) carbonate, it is obtained by heating basic copper carbonate in an atmosphere of carbon dioxide (produced by the decomposition of silver oxalate ($\ce{Ag2C2O4}$) at at 500 °C and 2 GPa (20,000 atm). This proves that basic copper carbonate is a precursor of copper(II) carbonate (it cannot be directly obtained by reaction of copper sulfate and sod. bicarbonate, first the basic carbonate forms and then the actual carbonate.)

This site claims to form copper(II) carbonate by reacting copper sulfate and sod. bicarbonate but it is actually basic copper carbonate as we can clearly see its color (bluish green - color of basic copper carbonate).

For advanced reading, you can refer to the last two papers in the references which describes Copper/bicarbonate equilibria in solutions of bicarbonate ion in details (which clearly shows formation of basic ion $\ce{CuCO3(OH)^2-}$ in the soln.)


  1. https://en.wikipedia.org/wiki/Basic_copper_carbonate
  2. https://en.wikipedia.org/wiki/Copper(II)_carbonate
  3. http://chemiday.com/en/reaction/3-1-0-5035
  4. http://science.wonderhowto.com/how-to/synthesize-copper-ii-carbonate-sodium-bicarbonate-302466/
  5. http://www.sciencemadness.org/talk/viewthread.php?tid=24056
  6. http://www.sciencedirect.com/science/article/pii/0043135471900492
  7. http://libraries.uark.edu/aas/issues/1941v1/v1a21.pdf

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.