The chemicals used in soda acid fire extinguisher as sodium hydrogen carbonate and sulfuric acid. The gas evolved when the two reactants react is carbon dioxide which is used for extinguishing electrical fires. Reaction will be between two chemicals are:

As detergent are basic in nature, the concentration of Hydroxide ions will be high and concentration of hydronium Ions will be less. [Note: When bases are dissolved in water they dissociate into Hydroxide ions]

The pH value of saliva after meal is around 5.8 due to the increased activity of bacteria on the food that we eat at any time.