Topic > Factors affecting the equilibrium reaction of iron...

Factors affecting the equilibrium reaction of iron (III) and thiocyanate ionsResearch questionHow does the temperature change of iron (III) work Thiocyanatoiron, containing iron ions ( III) Fe3+ (aq ) and the thiocyanate ions SCN¬¬- (aq), influence the absorbance of the solution? - Temperature at 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 ° C, 55 °C, and 60 °C (equilibrate the iron(III) thiocyanateiron (aq) at various temperatures using a digital water bath and monitor the temperature using a digital thermometer connected to a data logger) - Measured thiocyanate ion production rate from the degree of variation color using a colorimeter after 600 seconds after mixing the reagents. - The quantitative data of the absorbance of the solution will allow the determination of the concentration of Iron (III) Thiocyanateiron using the Beer–Lambert Law. The difference in solution concentration per temperature point gives the precise effect of temperature on the equilibrium position of the reaction. Introduction This experiment investigates how changing a factor that influences the equilibrium reaction, in this case temperature, influences the equilibrium position. Fe 3+ (aq ) + S︎CN – (aq) ⇌ Fe ( SCN ) 2+ (aq) ( ∆H = - ve )Pale yellow Colorless Blood redThis experiment uses the Iron (III) ion and the thiocyanate ion; the two chemicals are yellow and colorless, respectively. The product of the direct reaction is Iron (III) Thiocyanatoiron, which has a blood-red color. Dynamic equilibrium is when the macroscopic properties of the reaction are constant at a specific temperature when the rate of the forward reaction is the same as that of the forward reaction reverse reaction in a closed system. (Derry, Connor & Jordan, 2009) Le Chatelier's principle states that changing temperature, pressure or concentration will cause a shift in the reversible. (Derry, Connor & Jordan, 2009) The temperature, pressure and concentration of a chemical are factors that can cause a shift in the equilibrium position; the shift serves to compensate for changes brought about by one of the three factors. Since the forward reaction is exothermic, increasing the temperature increases the rate of the reverse reaction, which means that more Fe 3+ (aq) and S︎CN – (aq) will be formed, thus shifting the equilibrium position to the left, hence the solution will be in yellow.