2006-12-07 09:09:20 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
Endothermic reactions require that energy be put in before the reaction will occur. They will sometimes take energy out of the environment in the form of heat, and the surroundings will get cooler. Delta H (change in enthalpy) is positive for these reactions. On an energy plot, these reactions will end higher than they started because they take in energy. Melting and vaporization are examples.
Exothermic reactions give off heat upon the reaction occurring. The surroundings/container get warmer because of it. Delta H (change in enthalpy) will be negative for these reactions. On an energy plot, these reactions will end at a lower point than they start because they give off energy. Dissolving silica in highly basic sodium hydroxide solution is an example.
2006-12-07 09:17:32 · answer #1 · answered by calcu_lust 3 · 0⤊ 0⤋
Endothermic reactions take more energy than they put out to react. Exothermic reactions will emit energy, often in the form of heat or light, and end up giving more out more energy than it takes to reacte the two.
2006-12-07 09:13:09 · answer #2 · answered by George 2 · 1⤊ 0⤋
Contrast doing someone's homework for them and helping them with it. Do your own homework, genius.
2006-12-07 09:13:52 · answer #3 · answered by tycobb9999 2 · 0⤊ 0⤋