Is hydrolysis exothermic or endothermic?

2 Answers
Apr 1, 2016

endothermic

Explanation:

because in hydrolysis....bonds are broken....which means energy is absorbed....and if energy is absorbed it is endothermic

Aug 26, 2016

It depends on the particular reaction.

Explanation:

Two points to remember:

  • Breaking of bonds is always endothermic.
  • Formation of bonds is always exothermic.

Consider the hydrolysis of an ester:

"RCOOR"_1 + "HOH" → "RCOOH" + "R"_1"OH"

We could consider this simplistically as the breaking of two old bonds and the formation of two new bonds.

underbrace("RCO-OR"_1)_color(red)("break C-O bond") + underbrace("H-OH")_color(red)("break O-H bond") → underbrace("RCO-OH")_color(red)("form new C-O bond") + underbrace("R"_1"O-H")_color(red)("form new O-H bond")

The energy terms for breaking and forming the "C-O" and "O-H" bonds will be similar but not identical

Probably of more importance are the relative stabilities of the products and the reactants.

If a product is much more stable than a reactant because of resonance, inductive, steric, or solvation effects, the hydrolysis will almost certainly be exothermic.