Question

A. As a group, decide whether you want to support or refute the following statement and provide your justification.

“The use of activities is required to describe equilibrium concentrations when initial electrolyte concentrations equal or exceed 1 x 10-3 M.”

B. Brainstorm together. Can you think of any laboratory measurements where adding an electrolyte to a solution might be necessary?

C. In what ways have the equilibrium problem solving strategies you learned in general chemistry been challenged or expanded?

D. How did your group ascertain when a calculation was performed correctly? What strategies did you use to ensure that all group members could perform the calculations correctly?

Answer 1

A. The activities are actually used as a standard for ideal solutions as they include the ionic interaction inside the solution. Ideal solutions are alo termed as Highly concentrated solutions, whereas in the dilute solutions the concentrations are very low, the ionic interactions can be neglected due to large amount of solvent.
Hence for all dilute solution activities can be approximated to concentrations, here in our case the intial concentration is 1 x 10-3 M, which is diluted one and not concentrated, hence use of activities is not necessarily required (refute the statement).

B. Electrolytes play a important role in conducting eletricity due to the ions present in it, solution may or maynot contain ions. The case where the electrolyte is added to the solution is the addition of the glucose to the electrolyte mix in the body to maintain the blood pressure and control blow flow generally in infants.

C. The problem solving techniques or challenges faced in general chemistry while solving equilibrium problems are, regarding the equilibrium constant, which is constant and only depends on the temperature of the reaction, moreover the gibbs free energy of the reaction will be zero at equilibrium. The equilibrium constant is a thermodynamic quantity as it depends on the energy changes of the reaction.

D. The calculations performed in the laboratory shall be correct, only if the exepriment values are noted dowm 3-4 times for an average value and moreover for minimising the error value. The use of significant figures plays one of the major role in the calculations performed after the experiment.