Can someone explain why the reaction of hydrochloric acid with sodium hydroxide is so violently exothermic? I mixed the two together today and the beaker in which the reaction occurred became very hot.
2007-10-04 10:41:43 · 3 answers · asked by AxiomOfChoice 2 in Science & Mathematics ➔ Chemistry
bond breaking and forming. whenever you form water, it is gonna be exothermic.
2007-10-04 10:49:06 · answer #1 · answered by Carborane 6 · 0⤊ 0⤋
Two reasons: One is the formation of H2O. The other is the hydration of ions.
H2O is lower in energy than H+ and OH- separately, and the energy is given off as heat. Concentrated (36%) hydrochloric acid does not give off much heat when diluted with more water, but there is a little. The heating is more pronounced with NaOH(s). The Na+ and OH- interact with water even without acid, and the water gets quite warm.
You didn't mention H2SO4, but that can be really dangerous. You can boil water by adding 100% H2SO4to water. And one should never add water to 100% H2SO4, because the sudden boiling could throw hot acid back at the person.
2007-10-04 10:51:25 · answer #2 · answered by steve_geo1 7 · 1⤊ 0⤋
They form NaCl (table salt) and H2O (water) - two very stable compounds. Any time you go from reactive compounds to stable compounds, you release a lot of energy.
2007-10-04 10:46:51 · answer #3 · answered by Kenneth L 1 · 1⤊ 0⤋