Kinetics of forward extraction of Ti(IV) from H2SO4 medium by P507 in kerosene using the single drop technique

The kinetics of forward extraction of Ti(IV) from H2SO4 medium by P507 in kerosene has been investigated using the single drop technique. In the low concentration region of Ti(IV), the rate of forward extraction at 298 K can be represented by F(kmol · m−2·s−1) = 10−5.07[TiO2+][H+]−1 [NaHA2](o). Analysis of the rate expression reveals that the rate determining step is 2 (TiO)(i)2+ + (HA2)(i)− ↔ [TiO(HA2)(i)+. The values of Ea, ΔH±, ΔS±, and ΔG298± are calculated to be 22 kJ·mol−1, 25 kJ·mol−1, −218 J·mol−1·K−1, and 25 kJ·mol−1, respectively. The experimental negative ΔS± values indicate that the reaction step occurs via SN2 mechanism.