Why is a chemical change permanent?

Question

help?

Answer 1

isn't permanent, it just takes more energy to de-combine the ingredients.

Water is H20 and one of the most common substances on earth. The idea to create hydrogen fueled cars is a poor one because it takes more energy to break the oxygen and hydrogen bonds then you get from burning the hydrogen. Often this required electrical energy comes from coal fired plants so hydrogen cars would be pollutant free, but would create more pollution in the process.

There is a recent experiment that was reported in December's Popular Science where a scientist working on destroying cancer with radio waves found a way to separate water easier. By using a certain radio frequency and accidentally adding salt to the mixture it ignited; now of course water can't burn, but if you release the hydrogen that can burn.

The theory is that the radio waves can loosen the bonds of the water molecule making it easier for the salt ions to pull out the oxygen and oxidize. This frees the hydrogen. If this system becomes workable, the experiment repeatable, and one that is economical then a responsible way to create hydrogen fuel can be found by simply subjecting sea water to specific radio waves and capturing the released hydrogen. The product doesn’t even destroy the water because the burned hydrogen is still hydrogen and when it is released into the atmosphere it combines with oxygen to form more water. Of course there will be some matter lost in the chemical reaction, but as the atomic bomb shows it only takes a little matter to create a lot of energy. The problem then becomes what to do with the oxidized salt; that solution could be pretty easy if you pack it around nuclear waste. The Deaf Smith nuclear containment facility is an old salt mine in a very geologically stable area. The salt becomes a good stable buffer against the radiation.

Then some chemical reactions are only possible with the presences of catalysts. In the human body enzymes do this. The presence of the catalyst makes the reaction possible at a lower energy levels thus allowing animals to live, and the oil refining process to work. The best thing is that the catalyst doesn’t become involved in the reaction; it is only its presence that speeds up or makes the reaction possible at a lower energy level.

Chemical changes are not permanent, they just take energy to undo.

By the way photosynthesis uses solar energy to make the reaction possible; that is where the extra energy comes from to make the reaction possible.

Answer 2

No it is not. If given energy water molecules could be separated back to oxygen and hydrogen. Sugar when burned change into water and carbon dioxide, but plants reversed this process through photosynthesis.