I am an engineer and I understand the difference between baking power and baking soda as baking powder is baking soda (alkali) with tartaric acid (acidic) and an inert starch (why? Is this a catalyst in the presence of humidity and temperature).

So why use baking soda to deodorize a carpet and not baking powder? Is it because baking powder has both an acid and base and thus one would neutralize the other and would render the baking powder useless for adsorbing smells?

My carpet would be at a temperature of about $25~\mathrm{^\circ C}$. I am guessing this temperature and a relative humidity of $50{-}60~\%$ will not catalyze a violent reaction with either baking powder or baking soda?

Any input from chemists would be useful! I don't want to use either on my synthetic carpet in my rented house to experiment before I get enough input from people with know-how!

  • 1
    $\begingroup$ It's the bicarbonate ion that is doing the work, but in baking powder, it will react with the tartaric acid, so you'll have a significantly lower amount of bicarbonate to do the cleaning. $\endgroup$ Mar 21, 2013 at 23:30
  • $\begingroup$ Is the reaction of the bicarbonate with the tartaric acid an exothermic one at room temperature? Should I be worried about using baking pwd. on my carpet (notwithstanding it's lower "cleaning prowess" as compared to baking soda)? $\endgroup$
    – dearN
    Mar 22, 2013 at 12:36
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    $\begingroup$ The action on the carpet is unlikely to differ. The BP may turn out to be slightly less effective. The starch is likely a free flowing agent and not of much concern unless you wet it and it leaves a white residue. that is hard to vacuum out. $\endgroup$
    – KalleMP
    Mar 6, 2016 at 23:57

1 Answer 1


Baking soda is an effective deodorant because of its basicity. Many foul-smelling compounds are acidic. Neutralizing the compound gives it an ionic character which reduces the vapor pressure (meaning it is less available for the nose to smell it) and makes it much more water soluble (it can be washed away). Odorous compounds like fatty acids (butyric acid is BO) and thiols have much higher $pK_a$s (~4.8 and 7-10, respectively) than tartaric acid ($pK_a$ ~3) means that they would remain un-neutralized with baking powder. It would not be an effective deodorizer.


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