The word thermodynamics is derived from two Greek words, “thermo” and “dynamics” which mean “heat” and “power” respectively. Generally, thermodynamics is the study of heat energy that causes physical and chemical changes. In chemistry, it helps to explain whether a chemical reaction written is energetically possible or not. Thermodynamics does not tell the rate of reaction or the pathway of the reaction. Chemical thermodynamics is another term used in energy surfaces and spontaneous reactions. Chemical thermodynamics is the study of the link between work and heat during a chemical reaction.
There are two main laws of thermodynamics are used in energy surfaces and spontaneous reactions. The first law of thermodynamics states that energy can be transformed from one type to another type, but it cannot be created or destroyed. The first law of thermodynamics was also named the law of conservation of energy. The second law of thermodynamics states that entropy preset in an isolated system always increases. It is important to remember that the entropy of the universe always increases.
Several aspects of energy surfaces and spontaneous reactions can be difficult to understand. At Labster, we compiled all the complexities that students experience while learning energy surfaces and spontaneous reactions. Then, we provide five different methods to make this topic more interesting and simpler for students to learn. Ultimately, we will convince you why a virtual lab simulation is important for teachers to explain difficult topics like energy surfaces and spontaneous reactions to their students.
Figure: An image of Hess’s law taken from the Labster theory.
Three main reasons make energy surface and spontaneous reactions a difficult topic to remember.
Sometimes, it is difficult for students to remember abstract concepts. The reason is that they cannot see them. They need to read them from the textbook. In energy surfaces and spontaneous reactions, the reactions of substances and the product's formation occur at the molecular level. You cannot see the reactions with the naked eye. For that, you should be an expert in using a microscope. Hence, students may not get the abstract concepts and find the topic difficult to learn.
In energy surfaces and spontaneous reactions, students need to know the differentiation between exothermic and endothermic reactions, enthalpy of combustion and enthalpy of formation, and different laws of thermodynamics. These terms possess different statements, examples, and properties. Students dislike learning about energy surfaces and spontaneous reactions because it is a complex and time-consuming topic. They need to spend more time understanding energy surfaces' basic principles and processes and spontaneous reactions.
Students need to understand the basic process of how to make graphs on energy surfaces and spontaneous reactions. The graph is used to present the complicated data. Several graphs can be created to explain the relationship of energy with other substances. For instance, Hess’s law has the graph between the change in heat of reactants and products. In the same way, spontaneous reactions also possess graphs. Students may find it difficult to remember the graphs and feel the content is too heavy to learn.
Figure: An image of Hess’s law explanation from the Labster virtual laboratory of energy surfaces and spontaneous reactions.
Since we are familiar with the complications of the energy surfaces and spontaneous reactions. Five ways can be helpful for students to understand this complex topic.
Germain Henri Hess was a Swiss Russian chemist who introduced the thermochemistry principle and formulated Hess’s law. In 1840, his important work on thermochemistry law was published. He developed a principle related to the first law of thermodynamics that became known as Hess’s law. According to Hess, the gain and loss in energy only depend upon the initial and final steps in a chemical reaction. It does not depend upon the number of steps and path of the chemical reaction. Hess’s law is also called the law of constant heat summation. In 1842, he introduced the law of thermoneutrality. After the development of Hess’s law and the law of thermoneutrality, he gained popularity in the development of chemistry.
Many chemical reactions release energy that can be used for other processes. For instance, the fuel of the car is burned and released energy. This energy can be further used to power the car. Free energy is a kind of energy that is available for work. When spontaneous reactions proceed, they can release free energy.
Gibbs free energy is a state function and is defined as the thermodynamic characteristics that are state functions. The change in Gibbs free energy is equivalent to the change in enthalpy minus the product of the change in entropy and temperature. The symbol “G” is used to represent Gibbs free energy. Enthalpy is a process of measurement of energy from a thermodynamic reaction. The change in enthalpy is equal to the sum internal energy of the system with product of pressure and volume.
In a spontaneous reaction, the energy is released from the system. So, it the Gibbs free energy should be negative. But the change in enthalpy and the product of a change in enthalpy can either be negative or positive. Depending on the characteristics, there are four major combinations in Gibbs free energy.
If the enthalpy is negative and entropy is positive, then the Gibbs free energy is always negative.
If both the enthalpy as well as entropy are negative, the Gibbs free energy will be negative at low temperatures and positive at high temperatures.
If both the enthalpy as well as entropy are positive, the Gibs free energy will be positive at low temperatures and negative at high temperatures.
If the enthalpy is positive and entropy is negative, Gibbs free energy is always positive.
The spontaneous reaction does not need any external energy source and proceeds on its own. Since spontaneous reactions do not require energy, it does not that these reactions cannot absorb or release energy. In other words, spontaneous reactions are those reactions that need to be initiated and will continue in the process without external help.
Many spontaneous reactions are exothermic. Exothermic reactions are those in which heat is released from the system to the outside environment. Few spontaneous reactions are endothermic in nature. Endothermic reactions are those reactions in which heat enters to the system from the surrounding environment. In endothermic reactions, the system becomes warmer and the surrounding temperature reduces.
For example, the bonfire is a spontaneous reaction. Water vapors and carbon dioxide produce the fire. Also, the system's entropy increases in the combustion of the bonfire. In a bonfire, the entropy of the system increases, and the combination of energy reduces which shows the reaction is spontaneous.
Figure: An image shows the graph of the spontaneous reaction from Labster virtual laboratory of energy surfaces and spontaneous reactions.
Color images can be helpful for students to understand the energy surfaces and spontaneous reactions. The diverse colors use in images make them more attractive and also enhance the interest of students in learning boring topics. Virtual images make tough topics like energy surfaces and spontaneous reactions simpler for students to understand. It helps to convert the textbook information to a visual representation that can be easier for students to remember.
The image presented below shows Hess’s law. It provides information about the basic graph and the formulas of Hess’s law. Hess’s law states that when a set of products are formed from a set of reactants of chemical reactions, the change in enthalpy remains the same. By using this image, students can understand Hess’s law more appropriately.
Virtual lab simulation is an advanced method that helps to understand difficult topics like energy surfaces and spontaneous reactions. Basically, it is designed for teachers to explain the topic to their students. At Labster, we provide 3D simulations that have gamification elements like storytelling and a scoring system. These simulations are effective for learning complex topics.
Labster simulation on energy surfaces and spontaneous reactions explain the concepts of entropy, enthalpy, and free Gibbs energy. Additionally, you will understand the second law of thermodynamics, spontaneous reaction, the difference between the enthalpy of combustion and enthalpy of formation, Hess’s law, and the concepts of exothermic and endothermic reactions.
Check out Labster simulation on energy surfaces and spontaneous reactions here, or get in touch to know how you can start using virtual lab simulations with your students.
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