Question

My research question is investigating how temperature affects the rate constant for the reaction between ethyl ethanoate (acetate) and sodium hydroxide. I understand that I must titrate sodium ethanoate with an acid e.g.HCl, but that will just yield me the concentration of sodium ethanoate in the sample. How would I go about calculating the rate constant? Possibilities: Would I use the integrated rate law, with a concentration against time graph?Would I use the rate law expression? For this one I am unsure what I would use as the rate. The general process of trying to solve this problem: Determine starting molarities of each reactant. Let's say 0.1 M Have a set of sample collection tubes (test tubes) pre-measured with 0.1 M of standardized HCl that would yield a slight excess of moles of NaOH in the starting mixture. This will be used to STOP the reaction (more on this). I would choose at least 5.Setup your reaction batch and mix the reactants with enough volume. Probably 100mL of each would suffice. As well as make sure the reactants and mixture maintain a temperature desired.During set intervals, withdrawal 10mL of the reaction mixture at periodic intervals and place them into one of the sample tubes. Placing it in the tube will immediately quench the NaOH in the reaction sample and convert any remaining acetate ions to acetic acid.After each sample tube has been used, you can titrate the remaining HCl + acetic acid with a standardized NaOH solution and an appropriate indicator such as bromthymol blue to obtain the amount of acid present. You can now determine the amount of NaOH extracted from the reaction by using the number of moles of HCl present in the tube to start subtracted by the number of moles of acid that remain (step 5) to determine the amount of NaOH. Since we now know the amount of NaOH extracted in a 10 mL sample of the reaction batch, you can determine the concentration of the NaOH at time of extraction within the reaction batch AND the time it took to reach this concentration. Repeating this for each tube, we now have the change of the molarity of NaOH over time. This is also allows us to plot the change of the molarity of ethyl acetate since their reaction is a 1 mol : 1 mol ratio. Using the integrated rate laws, a plot of these concentrations over time, you can determine the slope of the plot which creates a linear graph and thus find the reaction constant(k).

Answer 1

To find the rate constant for the ethyl ethanoate and sodium hydroxide reaction, prepare and react the substances at a constant temperature, collect samples at intervals, immediately quench the reaction, and then titrate the samples.

Step-by-step explanation:

To calculate the rate constant for the reaction between ethyl ethanoate and sodium hydroxide at various temperatures, you need to follow a methodical approach involving titration, data collection, and analysis. First, prepare your reactants and set up the experiment to maintain a steady temperature. Collect reaction samples at predetermined intervals and quench them with an excess of standardized HCl to stop the reaction.

After quenching, perform a titration with standardized NaOH using an appropriate indicator to find the remaining amount of HCl, which will then allow you to calculate the concentration of NaOH at the time of extraction. With the 1:1 molar ratio between NaOH and ethyl ethanoate in mind, plot these concentrations against time.