Question

During the adsorption of krypton on activated charcoal at low temperature:

• A. $\Delta H<0$ and $\Delta S>0$
• B. $\Delta H>0$ and $\Delta S>0$
• C. $\Delta H<0$ and $\Delta S<0$
• D. $\Delta H>0$ and $\Delta S<0$

Answer 1

The correct option is C $\Delta H<0$ and $\Delta S<0$

During the adsorption of krypton on activated charcoal at low temperature.

$\Delta H<0$ and $\Delta S<0$.

Since adsorption is an exothermic process, the enthalpy change is negative. Heat is given out during the process.

The krypton gas adsorbed on activated charcoal is more ordered than unadsorbed krypton gas. Hence, the process occurs with a decrease in entropy.

In other words, the entropy change is negative for the process.