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

in the following reaction its clear the NaoH +HF àNaF+H2o because it heat lebrits more as compared to the other reactions

Answer 2

Answer: c) $NaOH+HBr\rightarrow NaBr+H_2O$

Explanation:-

Neutralization is a chemical reaction in which an acid and a base reacts to form salt and water.

The base is same in all the reactions. The acids are difference and among the acids HF, HCl and HBr: The strongest acid is HBr as on moving down the group the size of halogens increase and thus the bond formed between  small hydrogen atom and halogens keep becoming weaker.

Thus HBr is most acidic as it easily releases $H^+$ ions.

Thus HBr is the strongest acid and thus the enthalpy of reaction will be maximum.