Hi Dr. Sharma. I was redoing quiz 6.2 when I came upon this problem. I see that the temperature of the H2O initially and finally is the same, at 23.88°C. So the total energy absorbed by the water is 0 as the temperature change is also 0. So how come option B with product and reactant energies at the same is incorrect?

Thank you!
Siddharth 

Quote from: Siddharth_Pendyala on December 29, 2024, 12:30:15 PMHi Dr. Sharma. I was redoing quiz 6.2 when I came upon this problem. I see that the temperature of the H2O initially and finally is the same, at 23.88°C. So the total energy absorbed by the water is 0 as the temperature change is also 0. So how come option B with product and reactant energies at the same is incorrect?

Thank you!

If you carefully observe the data there is slight rise in temperature of water after 10 and 20 seconds .This means dissolution is exothermic with very small amount of energy released. This energy finally drops back to initial temperature because of loss of heat to the surroundings.
Since it is a simple dissolution process so there are no multiple steps.Option C is out and B and D is out.

Okay I think I understand now. Thank you!