Question

Which process is exothermic?

Answer 1

Answer: c. condensation of ethanol vapor

Explanation: An endothermic reaction is a type of of chemical reaction in which energy is absorbed from the surrounding. The temperature of the surrounding decreases.

An Exothermic reaction is a type of of chemical reaction in which energy is released into the surrounding. The temperature of the surrounding increases.

a.boiling of water: This involves conversion of liquid to gas and thus require energy and is endothermic.

b.melting of copper: This involves conversion of solid to liquid and thus require energy and is endothermic.

c. condensation of ethanol vapor:  This involves conversion of vapor to liquid and thus release energy and is exothermic.

d.sublimation of iodine: This involves conversion of solid to gas and thus require energy and is endothermic.

Answer 2

The exothermic process is a process or reaction that involves a release of energy from the system to its surroundings in various forms usually through heat, light, electricity or sound. In the four given choices, when melting a copper, you try to immerse the metal in  heaping coals of fire. The metal will absorb the thermal energy coming from the coal, thus, once you retrieve the metal back, light will be emitted from it as well as heat.

Therefore, the answer is B. MELTING OF COPPER