Question

write an equation to show why Na3PO4 AND NaCO3 also increase the effectiveness of detergent in water that has less than 5.

Answer 1

A) Dissolving either sodium carbonate, Na2CO3, or Na3PO4, in neutral water will produce a basic solution, increasing the pH. Both will neutralize acids to make an acidic solution less acidic., that is, the pH will increase.

Na2CO3(s) + HOH(l) --> 2Na+ + HCO3^- + OH-
NaHCO3(s) --> Na+ + HCO3^-
HCO3^- <==> CO2 + OH-
The production of hydroxide ion, OH-, shows that the solution is basic.

B) Since most dirt is acid, the alkaline in the detergent makes it a good cleaner for common dirt. For detergents to be effective most need to have the proper pH (percentage of hydrogen) which measures acidity and alkalinity. The scale goes from 0 to 14. Seven is halfway and is neutral. It is the balance between acidity and alkalinity. A solution that is acid will read 0-6 on the scale (6 being weaker than 1) and a solution that is alkali will be 8-14 on the scale (8 being weaker than 14).

Each number on the scale is a 10-fold difference from the adjacent number. For example, a pH of 5 is 10 times as acid as a pH of 6; a pH of 3 is 10 times the acid of 4 and 100 times as acid as 5. Different cleaners have different pH factors.

pH is very important in cleaning. Too strong a pH can damage surfaces, remove floor finish, as well as damage or discolor carpet fiber. It also can weaken carpet protectors.

Using an acid cleaner to do general cleaning will be of little value since most dirt is acid. The reason most shower cleaners are acid-based is because the soap residue is alkaline. Most general cleaning should be done with a pH of 9 and no more than 10. Anything stronger may damage surfaces and possibly void carpet warranties.