Question

Hess's law is applicable for the determination of heat of

Answer 1

Heating effect of current

The amount of heat produced by a current depends on these factors :

(i) The amount of heat is directly proportional to the square of current flowing through the conductor.

(ii) It is directly proportional to the resistance of the conductor.

(iii) It is also directly proportional to the time the current takes to flow.

H = heat produced .

I = current .

R = resistance .

T = time .

H ∝ I²

H ∝ R

H ∝ T

Thus H ∝ I²RT

= > H = I²RT

This is also called Joule's Law of heating .

Answer 2

Hess's law states that the change of enthalpy in a chemical reaction (ie the heat of reaction at constant pressure ) is independent of the pathway between the initial and final states