The Essence, Significance and Relationship of Polybasic Acid or Polybasic Base Titration Condition

The essence, significance and relationship of Polybasic Acid or Polybasic Base titration conditions were revealed with the titration curve. The findings showed that: K_i/K_i+1 is the determining factor of stepwise titration and the primary indicator that influences the titration jump; while c_spi K_i is the key which determines the jump value when K_i/K_i+1 is enough large. The decision procedure of before-titration is: first, to determine whether the K_i/K_i+1 of the measured object is greater than or equal to 10⁵, so as to see whether the stepwise titration is applicable; then it is to determine whether c_spi K_i is greater than or equal to 10^-9, so as to see whether accurate titration can be directly applied under the current conditions.