Deionized Water

• Deionized or demineralized water is water with its cations and anions removed by an ion exchange process. Tap water generally contains these ions from soil, pipes, and other sources. Purified water is an example of deionized water.
  
  

Water Purity

• Deionization produces pure water similar to distilled water. Pure water is a neutral solution because the base [OH-] concentration is the same as the acid [H+] concentration. The molarity of the acid and base in pure water is negligible, one 10 millionth mol/L.
  
  

Deionized Water Effect on Concentration

• Deionized water concentration has no effect or remains constant for reactions in water; thus, you can omit its molarity from the acidity constant expression. This enables your experiments to obtain true results.