Physics - Heat & Thermo Question with Solution | TestHub
Equal quantities of a salt are dissolved in two identical vessels filled with water. In one vessel, the salt is in the form of powder and in other it is in form of a crystal of same mass. In which vessel will the temperature of the solution be higher after the salt is completely dissolved.
Evaluate the following statements.
Statement I: The final temperatures are equal if initial states, final solution states and thermal isolation are identical.
Statement II: The powder necessarily gives a higher final temperature because it dissolves faster.
Options:
Answer:
Solution:
The final temperature is the same in both. Heat of solution is the same for the same mass of salt dissolved in the same water (energy is a state function). The powder only dissolves faster (more surface area), so the temperature change is reached sooner. This assumes both vessels are insulated, initially at the same temperature and reach the same final solution state; different heat losses during dissolution can change actual observed temperatures. Statement I is true and Statement II false. Correct option: (B).
