What Is Chemical Energy?
Chemical energy is a very hidden energy. It cannot be used directly for work. It can only be released when chemical changes occur, and it can be converted into thermal energy or other forms of energy. Energy such as the burning of oil and coal, the explosion of explosives, and the chemical changes in the food eaten by humans are all chemical energy. Chemical energy refers to the energy stored in matter. According to the law of conservation of energy, the change in this energy is equal to the change in thermal energy in the reaction, with the opposite sign. When the atoms of the participating compounds are rearranged to produce a new compound, Changes in chemical energy will result in exothermic or endothermic effects.
- All chemical reactions are essentially
- Various substances store chemical energy. Different substances not only have different compositions and structures, but also contain different chemical energy. in
Chemical energy to heat energy
- Chemical reactions follow the law of conservation of mass before and after the reaction; similarly, one kind of energy can be converted into another kind of energy, and energy is also conserved. This is the "energy conservation law"
Practical application of chemical energy
- Humans not only use the principle of converting chemical energy into thermal energy to obtain the required heat for life, production and scientific research, such as the combustion of fossil fuels, the opening of explosives, and the launch of rockets. Chemists also often use thermal energy to enable many chemical reactions to occur, in order to explore the composition, properties, or materials required for preparation, such as high-temperature smelting of metals and decomposition of compounds.
Chemical energy meaning
- A chemical reaction accompanied by a change in energy is a major feature of chemical reactions. The chemical energy in chemical substances is converted into thermal energy through chemical reactions, which is the source of power for human survival and development; and the conversion of thermal energy into chemical energy is an indispensable condition and way for people to carry out chemical scientific research and create new substances. [2]
Chemical to Bioenergy
- "Respiration" refers to the process by which an organism inhales oxygen and exhales carbon dioxide, and "cell respiration" refers to the process by which organic matter in a cell oxidizes and releases energy.
Chemical energy respiration type
- Aerobic respiration: (under the action of enzymes)
- C 6 H 12 O 6 + 6H2O + 6O 2 6CO 2 + 12H 2 O + energy
- 1mol glucose releases 2870KJ, 1161KJ is transferred to ATP (38mol ATP is synthesized), the energy efficiency is as high as 40%, and the rest is mainly lost in the form of thermal energy (1709KJ).
- Anaerobic respiration: (under the action of enzymes)
- C 6 H 12 O 6 2C 2 H 5 OH + 2CO 2 + energy
- C 6 H 12 O 6 2C 3 H 6 O 3 + energy
- 1mol glucose is decomposed into lactic acid to release 196.65KJ energy, 61.08KJ is transferred to ATP (2mol ATP is synthesized), and the rest is lost in the form of thermal energy.
Chemical energy meaning
- 1.ATP provides energy for life activities
- 2. Thermal energy keeps body temperature constant [3]
Chemical energy to electricity
- How chemical energy is converted into electrical energy:
- The primary battery directly converts chemical energy into electrical energy. Advantages: clean and efficient
Chemical energy battery principle
- 1. Concept: The device that directly converts chemical energy into electrical energy is called a primary battery.
- 2. The working principle of the primary battery: chemical energy is converted into electrical energy through redox reaction (electron transfer).
- 3. Conditions for forming a primary battery: (1) the electrodes are conductors and have different activity; (2) the two electrodes are in contact (wire connection or direct contact); (3) the two connected electrodes are inserted into the electrolyte solution to form a closed circuit.
- 4. Name of electrode and reaction:
- negative electrode:
- The more active metal is used as the negative electrode, and the negative electrode undergoes an oxidation reaction.
- Electrode reaction formula: more active metal -ne-= metal cation
- Negative electrode phenomenon: the negative electrode dissolves, and the negative electrode mass decreases.
Positive :
- The less active metal or graphite is used as the positive electrode, and the positive electrode undergoes a reduction reaction.
- Electrode reaction formula: cation + ne = element in solution
- The phenomenon of the positive electrode: Generally, gas is emitted or the mass of the positive electrode is increased.
The main types of chemical energy
- 1. Dry battery: Live metal is used as negative electrode, which is corroded or consumed. Such as: Cu-Zn primary batteries, zinc-manganese batteries.
- 2. Rechargeable battery: the primary battery with both poles participating in the reaction, which can be charged and recycled. Such as lead batteries, lithium batteries and silver-zinc batteries.
- 3. Fuel cell: Both electrode materials are inert electrodes. The electrode itself does not react, but reacts with the materials introduced to the two electrodes, such as H 2 and CH 4 fuel cells. The electrolyte solution is often alkaline reagent (KOH). Wait). [4]