Hi Friends...
Good Morning.....
Please answer this question :-
Predict the sign ΔS for the following reaction :-
CaCO3(s) ------> CaO(s) + CO2 (g)
Thank You....
^_^
Answers
Hello Anaida....It's Your Friend here^_^
S means Entropy...And Entropy means Randomness....So we know......Gas is more random than the solid......So...In the product side...We have a gas...And no gas in reactant side...So Randomness is increasing as the reaction proceeds towards the product side ( Forward reaction)...Which means S is positive.
Always do remember that o r d e r of randomness is Gas> Liquid>Solid...More the randomness...More is the entropy.(Entropy is the measure of randomness)
So...In this t y p e of questions....Just check..The P h a s e of the reactants and products and see if the randomness is increasing or decreasing as the reaction proceeds....If randomness is increasing...S is positive...If decreasing S is negative.
Once again...In this Case..It's solid on reactant side...And We have CO2 gas in product side...Gas has more randomness..So randomness is increasing towards product side...And do S is positive
Btw Anaida..In the answer...Please do note that it is "Delta S" and not S...There is a considerable difference between Delta S( Change in Entropy) and S( Entropy)