When lithium chloride dissolves in water, the temperature of the solution increases. Which diagram represents the enthalpy changes of the steps in the solution-making process? (LO 13.2)

Video transcript

Hello everyone today. We have the following problem. The temperature of the solution increases when calcium chloride is dissolved in water, which diagram shows variations in entropy that occur throughout the solution making process. So it's important to recall that when you have an increase in the temperature of a solution, this is going to mean that the reaction is XR thermic or there's heat that is being released and as a result the entropy or change in entropy is going to be negative or less than zero because heat is released more so in the opposite fashion. The lower the temperature is going to indicate that it is endo thermic because energy is being absorbed from the solution. So our entropy change is going to be positive Or greater than zero. For the question, it stated that calcium chloride in water causes the temperature of the solution to increase which indicates that heat is released and we are going to end up with an exhaust thermic reaction which is going to state that our change an NDP will be less than zero. So when in the process of this dissolving, this is going to require heat for the bonds to break. It's going to require heat to break the bonds. What that means is we're going to have our LP of the salute which is the calcium chloride or the entropy of the salute with the salute. That is going to be indo thermic because it is going to have to observe absorb the heat energy to break those bonds. Now when it comes to our water or our H20. Our H20 is also going to require heat to break the forces between the water molecules. So that is going to be indicative that the entropy of the solvent solvent interactions is also going to be endo thermic. Thus we can conclude that this relationship is going to look like the entropy of the solution is equal to the entropy of the solute solute interactions plus the entropy of the solvent solvent interactions plus of course the entropy of the sol ute minus the sol or not minus the entropy of the salute and the soul vent interactions. And so the graph that best represents this is going to be graph D. In graph D. We have that the entropy of the solution is going to be below that of the entropy of our solute solvent minus R. So you saw you and sol event. Event. And with that we've answered the question overall, I hope this helped. And until next time.