Question

In a mixture of $A$ and $ \, B$ , components show negative deviation when -

• A. $A-B$ interaction is stronger than $A-A$ and $B-B$ interaction
• B. $A-B$ interaction is weaker than $A-A$ and $B-B$ interaction
• C. $\Delta V_{\text{mix}} >0, \, \Delta S_{\text{mix}} >0$
• D. $\Delta V_{\text{mix}}=0, \, \Delta S_{\text{mix}} >0$

Answer 1

Answer: (A)

Negative deviation is when $A-B$ (solute-solvent) interaction is stronger than $A-A$ (solute-solute) and $B-B$ (solvent-solvent) interaction. Hence $\Delta V_{\text{mix}} < 0, \, \, \Delta H_{\text{mix}} < 0$