Question

A piece of iron is heated and then cooled by dropping it in water. The heat lost by the piece would be higher if A) the initial temperature and final temperature are raised by 10°C. B) the initial temperature and final temperature are lowered by 10°C. Eliminate C) the initial temperature is raised and the final temperature is lowered by 10°C. D) the initial temperature is lowered and the final temperature is raised by 10°C.

Answer 1

I think its C but im not positive.

Answer 2

Answer: Option (C) is the correct answer.

Explanation:

Whenever heat is lost in a chemical reaction or by a substance then the value of $\Delta H$ will be negative.

And, when heat is absorbed in a chemical reaction or by a substance then the value of $\Delta H$ will be positive.

As change in temperature is calculated as follows.

              $\Delta T$ = Final temperature - Initial temperature

So, when the value of initial temperature is raised and value of final temperature is lowered then the final change in temperature will come out to be negative.

This will show that heat lost by the piece would be higher.

Therefore, we can conclude that heat lost by the piece would be higher if  the initial temperature is raised and the final temperature is lowered by $10^{o}C$.