Tuesday, April 1, 2008

Exothermic and Endothermic Reactions

hi there i would like to ask a qn regarding the chapter on energy changes
and hope you will reply. (:

When steam is passed through white-hot coke, a reaction occurs and the
temperature of the coke falls.What does this indicate? Answer: The reaction
is endothermic(this is a mcq qn) Why is the answer endothermic?Since the
temperature of the coke falls, isnt it giving out energy?

By giving out energy, thus the temperature falls.And the definition of
exothermic is heat exitswhile for endothermic it is heat taken in.So, why isnt
the answer exothermic then?

P.S i find this chapter the terms exothermic and endothermic quickly
deceiving and confusing.


RingSound said...

Endothermic mean a reaction require heat energy input such as heating the reactant. Thermal decomposition of calcium carbonate.

exothermic mean the reaction release heat energy
which mean when the reaction start, it gives out heat
for example acid-alkali neutralization

Sean Chua said...


I have made an earlier post at my Chemistry Blogsite at

You can see my suggested answer at:

Hope that helps.