# Mole Ratio Essay

530 Words3 Pages
Introduction During the course of the experiment the enthalpy change of a series of reactions were measured. The main goal was to determine the stoichiometry of an oxidation-reduction reaction in which the reactants are known (NaOCl) & (Na2S2O3 in NaOH). Procedure • First step was to set up the temperature probe and started the logger pro program. • Measured 25.0mL of the 0.50 M NaOCl solution in a stabilized Styrofoam cup and immersed the tip of the temperature probe in the cup of this solution allowing the program to gather graph a few initial Temp. readings for data collection. • Then 25mL of the Na2S2O3 solution was added to the previous solution while stirring the reaction mixtures with the temperature probe. • Data collection should stop after 3 minutes or may be stop if temp reaches a stand still before the 3 minute time frame. • Maximum temperature change is to be recorded as data. • Steps are repeated various times at a volume of 50mL to get three measurements on either side of the ratio that produces the greatest temp change. Discussion DATA TABLE Initial Temp (C) Volume OCL- (mL) Volume S2O3^2- (mL) Temperature Change (C) Final Temp (C) 23.2 25mL 25mL 12.2 C 35.4 C 23.7 20 mL 30mL 10.3 C 34 C 23.7 30 mL 20mL 16.1 C 39.8 C 23.5 40mL 10mL 22 C 45.5 C 23.7 45 mL 5mL 12.4 C 36.1 C Results Based on the data it was found that the thiosulfate solution was the limiting reactant, because temperature decreased. Mixing different volumes of the two reactants resulted in different temperature changes. The temperature change was directly proportional to the quality of reactants consumed, because the goal of the experiment was to make the volume of the solution and the total number of moles of the reactants constant. Therefore leaving the optimum ratio; that was determined after the results of the experiment to be the ratio of the