Supposed you stoppered the flasks after your titration to determine the equilibrium constant and kept the solutions for another day so that the equilibrium was re-established. What would happen to the amount of ethanol present? What would be the relationship of the original equilibrium constant you calculated to the new one?
Okay so this is my attempt at the answer, but I'm really not sure if this is right:
Because ethanol is more volatile than water, some of it, after a day, will evaporate, so we'll have less products, so the equilibrium constant will be different from the one we have and so the equilibrium will be towards the right to compensate for the evaporated ethanol, so K < 1.
Is this correct?
Thank you!
oh okay, well in that case there's no change? Nothing happens to the ethanol and we get the same K constant that we had previously?
I'm in the dark as to what you did.
oh this is just a theoretical question. It's about the hydrolysis of ethyl acetate, it gives ethanol and acetic acid as the products
It appears to me that if you stoppered the flask there is no question that the ethanol could NOT evaporate.
Supposed you (stoppered) the flasks
ethyl acetate + water ---> ethyl alcohol + acetic acid
Once stoppered and allowed to reach equilibrium again. It will be in the reverse direction
ethyl alcohol will react with acetic acid to form water and ethyl acetate
Your attempt at the answer is partially correct, but let me explain in more detail.
When you initially performed the titration to determine the equilibrium constant, the system reached a state of equilibrium between the reactants and products. The equilibrium constant (K) you calculated at that time represents the concentration ratio of products to reactants at that specific temperature.
If you stoppered the flasks, preventing any substances from escaping, the system would remain at equilibrium. However, if you kept the solutions for another day, the equilibrium would be disrupted. As you correctly mentioned, ethanol is more volatile than water, meaning it can readily evaporate.
As the ethanol evaporates, the overall concentration of ethanol in the solution decreases. This alters the concentration ratio of products to reactants and shifts the equilibrium to compensate for the loss. According to Le Chatelier's principle, the system will try to counteract the decrease in ethanol concentration by favoring the forward reaction, which produces more ethanol.
In other words, with less ethanol present, the equilibrium will shift towards the right, favoring the forward reaction to produce more ethanol until a new equilibrium is established. As a result, the concentration of ethanol will increase gradually over time, approaching the new equilibrium concentration. However, it is important to note that this process may not reach completion, especially if the initial ethanol concentration was very low.
Regarding the relationship between the original equilibrium constant you calculated and the new one, the new equilibrium constant (K') will be different from the original (K). The change in concentrations due to evaporation will lead to a different equilibrium constant. The precise relationship between K and K' can vary depending on the reaction, but generally, the new equilibrium constant will be smaller than the original one (K' < K).
To summarize, if you stoppered the flasks after the initial titration and allowed the solutions to sit, the amount of ethanol present would gradually increase as it evaporates and the equilibrium shifts to produce more ethanol. The new equilibrium constant (K') would be different from the original one (K), with K' being smaller due to the change in concentrations caused by evaporation.