Question

The enthalpy of reaction is maximum in which of the following reaction? a) NaOH + HCl--------> NaCl + H2O b) NaOH + HF ---------> NaF + H2O c) NaOH + HBr ---------> NaBr + H2O d) All of these the answer is the 2nd option but can you pls explain it

Answer 1

The enthalpy of reaction is maximum in reaction b. That is

NaOH + HF ----------> NF + H2O

this is because it liberates more heat as compared to the other reactions.

What you need to appreciate is that all these hydrogen halides vary in the rates at which they are reacting with different compounds due to the fact that they themselves vary in their elctronegativities.

And this is normally contributes to how they react.

Fluorine is the most electronegative followed by chlorine then bromine and finally iodine.

Answer 2

Answer:Fluorine is the most electronegative followed by chlorine then bromine and finally iodine.

That is why option b is correct..