Greetings,
This is the first post of the third main topic of this blog, Changes in Matter. A study of the first two topics, Identity of Matter and Structure of Matter, treat atoms/ions/molecules as though they are static and noninteractive. The reality is that the fundamental particles of matter are in constant motion and interact greatly with other basic particles.
In chemistry, we see the motion and interactions of fundamental particles manifest as two main types of changes; (1) Changes of State and (2) Chemical Reactions. A change of state is a physical change and only changes the physical properties of matter, not the identity or chemical composition of matter. A chemical reaction results in a complete change of chemical composition and can only be reversed by a chemical process.
A change of state and a chemical change also involve a change in heat energy, either released or absorbed. Heat energy is closely associated with the extent of particle motions and the degree of interaction between particles. Specifically, there are two types of heat energy involved in physical and chemical changes; potential and kinetic. Potential energy is energy stored up within interactions and chemical bonds between fundamental particles. Kinetic energy is connected to the speed of motion of basic particles and increases with increasing temperature. It is interesting that a change of state, such as solid to gas, always involves a release or absorption of heat energy while temperature remains constant. It is also important to note that the total energy involved in a physical or chemical process remains constant. What does change are the amounts of potential and kinetic energy, but the sum total of them does not change. The following graphic depicts the changes in heat energy just described.
A couple notes about the chart...
The constant total heat energy for changes of state is the sum total of the kinetic energy and potential energy for each phase. For the reaction progress charts, the E's are the energy absorbed and the energy released, viewing the charts from left to right. The main point here is that a reversible reaction will have the same amount of heat "flowing" for both the forward and reverse reactions, only the direction of the heat flow changes. The E values can also be thought of as a decrease in kinetic energy for the electrolysis reaction and an increase in kinetic energy for the formation reaction.
My next post will summarize the specific topics to be covered for this third main section, Changes in Matter.
Happy New Year to All!
Thank you for reading.
See the "Parent" Site, http://www.excellenceinlearning.biz
This is the first post of the third main topic of this blog, Changes in Matter. A study of the first two topics, Identity of Matter and Structure of Matter, treat atoms/ions/molecules as though they are static and noninteractive. The reality is that the fundamental particles of matter are in constant motion and interact greatly with other basic particles.
In chemistry, we see the motion and interactions of fundamental particles manifest as two main types of changes; (1) Changes of State and (2) Chemical Reactions. A change of state is a physical change and only changes the physical properties of matter, not the identity or chemical composition of matter. A chemical reaction results in a complete change of chemical composition and can only be reversed by a chemical process.
A change of state and a chemical change also involve a change in heat energy, either released or absorbed. Heat energy is closely associated with the extent of particle motions and the degree of interaction between particles. Specifically, there are two types of heat energy involved in physical and chemical changes; potential and kinetic. Potential energy is energy stored up within interactions and chemical bonds between fundamental particles. Kinetic energy is connected to the speed of motion of basic particles and increases with increasing temperature. It is interesting that a change of state, such as solid to gas, always involves a release or absorption of heat energy while temperature remains constant. It is also important to note that the total energy involved in a physical or chemical process remains constant. What does change are the amounts of potential and kinetic energy, but the sum total of them does not change. The following graphic depicts the changes in heat energy just described.
The constant total heat energy for changes of state is the sum total of the kinetic energy and potential energy for each phase. For the reaction progress charts, the E's are the energy absorbed and the energy released, viewing the charts from left to right. The main point here is that a reversible reaction will have the same amount of heat "flowing" for both the forward and reverse reactions, only the direction of the heat flow changes. The E values can also be thought of as a decrease in kinetic energy for the electrolysis reaction and an increase in kinetic energy for the formation reaction.
My next post will summarize the specific topics to be covered for this third main section, Changes in Matter.
Happy New Year to All!
Thank you for reading.
See the "Parent" Site, http://www.excellenceinlearning.biz
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