KCET2010ChemistrySurface Chemistry
During the adsorption of krypton on activated charcoal at low temperature
Options
- AH >0 and S < 0
- BH < 0 and S < 0
- CH >0 and S >0
- DH 0
Correct answer
B. H < 0 and S < 0
Step-by-step solution
Adsorption is an exothermic process, thus H is negative (ie, H < 0 ). Moreover, adsorption results in more ordered arrangements of molecules, thus entropy decreases (ie, S < 0 ). G = H - T S Hence, low temperature favours the reaction.