[Corvettaholic]

After the thread of applying energy to break certain bonds, that got me thinking as to how to actually "apply" energy. Sure, I could smack something with a hammer, stick a car battery to it, or toss it in a fire, but how I KNOW how much energy I'm delivering in kJ? I can look up molar weight from some table online, but I can't find how much energy (energy can be expressed as kJ, right?) certain things generate.