Why do we prepare very dilute solution of KNO3 to calculate enthalpy of its solution?
Answers
Answer:
answer
Explanation:
No change in enthalpy is expected because there is no change (no reaction).
KNO3 solution contains K+ and NO3- ions.
NaBr solution contains Na+ and Br- ions.
When the two solutions are mixed, the solution contains K+, NO3-, Na+ and Br- ions. Nothing has changed.
You may assert that KNO3 reacted with NaBr and gave KBr and NaNO3. This happens only in your mind and not in the solution. Because even if the reaction really happened and the solution now contains KBr and NaNO3, what you have in solution is still K+, Br-, Na+ and NO3- ions. What is the difference?
You have two cations and two anions in solution. That is the reality.
Of these, which cation is considered as the pair of which anion, that is your choice. It happens only in your imagination.
You can say that the solution contains KNO3 and NaBr, or you can say that the solution contains KBr and NaNO3; it is your choice. But in either case, what you have in solution is the same, so nothing has happened in the solution. Therefore there is no energy change