1. Dnyanasadhana College, Thane.
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Department of Chemistry T.Y.B.Sc. Analytical Chemistry Paper-IV Sem-VI
Thermometric Titrations
Dr.Bhagure G.R.
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2. Contents
4.1.4 Thermometric Titrations –Introduction, Instrumentation, Applications in the titration of :
(i) HCl v/s NaOH (ii) Boric acid v/s NaOH
(iii) A mixture of Ca+2 and Mg+2 v/s EDTA
(iv) Zn+2 with Disodium Tartarate.
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3. Thermometric Titrations
Thermometric Titrations is defined as titration in which end point is determined by measuring the heat generated during chemical reaction
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4. Principles of Thermometric Titrations
In the thermometric titration, titrant   is added at a known constant rate to a titrand until the completion of the reaction is indicated by a change in temperature. The endpoint is determined by an inflection in the curve generated by the output of a temperature measuring device
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5. aA bB pP Heat Consider the titration reaction
A = the titrant, and a = the corresponding number of moles  B = the analyte, and b = the corresponding number of moles P = the product, and p = the corresponding number of moles produced
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6. At completion, the reaction produces a molar heat of reaction ΔHr which is shown as a measurable temperature change ΔT. In an ideal system, where no losses or gains of heat due to environmental influences are involved, the progress of the reaction is observed as a constant increase or decrease of temperature depending respectively on whether ΔHr is negative (indicating an exothermic reaction) or positive (indicating an endothermic reaction)
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7. THERMOMETRIC TITRATION ASSEMBLY
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8. Instrumentation of Thermometric Titrations
Motor driven burette
Dewar flask
Thermistor
Recorder
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10. Applications of Thermometric Titrations.
Applications of Thermometric Titrations ..
Titration of HCl V/S NaOH …
Titration of Boric acid V/S NaOH ….
Titration of Calcium & Magnesium V/S EDTA
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11. Titration of HCl V/S NaOHD C
Change in Temperature Δt
The heat of neutralization of a fully
dissociated acid with a fully dissociated
base is approximately –56kJ/mol. B A
Equivalence point
Volume of NaOH added 
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12. Titration of Boric acid V/S NaOH
Change in Temperature Δt
Equivalence point
Volume of NaOH added 
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13. Titration of Calcium & Magnesium V/S EDTA
calcium reacts exothermically with EDTA
(heat of chelations = kJ/mol),
magnesium reacts endothermically with
a heat of chelation of = kJ/mol B
Change in Temperature Δt C A D
Equ. point of Ca2+
Equ. point of Mg2+
Volume of NaOH added 
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