What is the enthalpy change when 49.4ml of 0.430M sulfuric acid reacts with 23.3ml of 0.309M potassium hydroxide? H2SO4(aq)+2KOH(aq)+2H2O(l)
Delta H= -111.6 kj/mol

In all electrically-neutral atoms, the number of electrons is the same as the number of protons. This is known as the octet rule which states that, with the exception of the innermost shell, atoms are more stable energetically when they have eight electrons in their valence shell, the outermost electron shell.