SOLVAY PROCESS
Preparation of Sodium Bicarbonate
NaHCO3

Sodium Bicarbonate is a common household chemical known as Baking Soda. It is inexpensive, abundant and slightly basic. It also generates carbon dioxide gas when heated or exposed to acids.

These characteristics account for its wide use in cleaning products, odor removal, tooth paste, fire extinguishers and baking. Along with citric acid, it puts the fizz in Alka SelzerŪ

There is a............. TUTORIAL
There is a............. VIDEO (189 MB)
There is the......... PHENOLPHTHALEIN STORY

Return to......... SYLLABUS
Return to......... PRELAB

NH3 + CO2 + H2O + NaCl = NaHCO3

Students who have done the NonMetals experiment will recognize CO2 as an acidic gas and NH3 as a basic gas.
The reaction of the two is an acid base reaction which gives off heat and produces a salt, NH4HCO3 with excess CO2.
You will use a pH indicator, phenolphthalein, to track the change in pH as CO2 is added.
NOTE: NH3 is very soluble in water giving rise to a solution called "Ammonium Hydroxide". 

 

Sodium Bicarbonate is currently obtained from trona found in western playas. These are deposits of carbonates found in the desert.

Although formerly manufactured by the Solvay Process, this is no longer an economically viable route. The byproduct solutions from this process, with their high concentrations of chloride ion, produced pollution problems too costly to solve in view of the low production costs from mining the trona playas.

QUESTIONS

  1. Recall the "Nonmetals" experiment. The reaction of carbon dioxide with ammonia is an acid base reaction. Which is the acid and which is the base?......... answer

  2. How does Sodium Bicarbonate work to remove odors?..... answer

  3. Why is Sodium Bicarbonate put in toothpaste?................... answer

  4. How does Sodium Bicarbonate work in fire extinguishers?.. answer

  5. How does Sodium Bicarbonate work in baking?.................. answer