Chemical energy may conjure up images of laboratories, burners, and test tubes. But while the study of chemical energy certainly involves the sciences, we can learn more about its impact on our everyday lives even we’ve never stepped foot inside a lab.
Just what is chemical energy? It’s something in the food we eat, the electricity we generate, and even plants. Let’s understand this vital energy source to gain a deeper appreciation for its presence and power.
What Is the Definition of Chemical Energy?
Chemical energy is an energy store, one of the most crucial energy stores available to us. Energy stored in an object is a form of potential energy.
The potential energy of chemical energy is found stored in the chemical bonds that bind atoms in molecules. Breaking these bonds apart or reforming them by adding fuels or reactants releases the chemical energy in the bonds. We call this breaking and forming of bonds a chemical reaction. A new substance is created after a chemical reaction.
The fuels or reactants provide the energy required to transform chemical potential energy into chemical energy. Our ability to transport chemical potential energy and harness chemical energy is why it has become fundamental to our energy systems.
What Is Potential Chemical Energy?
We know the potential chemical energy stored in an object because of the number and type of chemical bonds it contains. Understanding these values helps us choose how to use chemical energy.
Motor vehicles are a prime example to consider. A van with an empty fuel tank parked at the top of a hill has the potential energy to move down the hill. That same van at the bottom of a hill has less potential energy because it will not easily move uphill.
However, if we fill its tank with gasoline, we are filling it with fuel made up of various chemical compounds. The van’s combustion engine burns the gas, creating new substances by breaking and reforming bonds within the gasoline’s molecules and atoms. A certain amount of energy is used to move the van, and some of it creates heat.
Many fuels like biofuels, propane, methane, and more have potential chemical energy. We generate electricity at power plants by burning fossil fuels like natural gas, coal, and petroleum, releasing these materials’ potential chemical energy.
These reactions are called exothermic reactions.
What Takes Place During an Exothermic Reaction?
A chemical reaction that produces heat is exothermic, warming its surroundings thanks to the energy released during the process.
Exothermic reactions are an everyday part of our lives. We’ve already seen how combustion reactions, or burning, happen when we burn fuels. This chemical reaction releases thermal energy in the form of heat energy — imagine the flames of a fire or a natural gas power plant.
Another exothermic reaction is crucial in the battle against climate change. Burning coal in a power plant creates a chemical reaction between the coal’s stored carbon and ambient oxygen, which combine to release carbon dioxide and heat. These exothermic reactions take place when a substance reacts with oxygen. We call them oxidation reactions and they also produce oxides.
A painful reminder of another exothermic reaction occurs when a bee stings us. A bee sting is acidic, and an old remedy is to treat it with baking soda. What is happening at a molecular level is called a neutralization reaction. This reaction occurs when an acid like a bee sting interacts with substances called bases such as baking soda. We call this a neutralization reaction when the chemical reaction produces water and salt.
With exothermic reactions, more energy is released as new bonds form than the energy required to break the bonds in the reactants.
What Is an Endothermic Reaction?
If an exothermic reaction adds heat to its surroundings, then an endothermic reaction performs oppositely. An endothermic reaction absorbs heat energy from its surroundings, cooling them down and using energy.
The easiest way to picture endothermic reactions is photosynthesis. Plants absorb the sun’s heat energy and convert it into glucose to later use for growth. Another example is the heat energy absorbed by a saucepan to boil water and heat food.
How Is Potential Energy Converted to Chemical Energy?
In thermodynamics, the law of conservation of energy, also known as the first law of thermodynamics, states energy cannot be destroyed or created. Rather, energy can only transform from one form of energy into another.
We’ve seen how a substance’s potential energy transforms into chemical energy with the breaking and reformation of bonds between atoms in molecules. A new substance, or substances, comes into existence. We call this an exothermic reaction if the reaction creates more energy than was initially stored. An endothermic reaction is a reaction that absorbs or uses more energy than was stored.
Food is a tasty way to understand chemical energy. Let’s head to the groves of California and pick a juicy orange. The orange tree has grown and produced an orange thanks to photosynthesis. The tree converted the sun’s energy into carbohydrates like glucose via photosynthesis. Glucose is the tree’s store of potential energy, and we can find it in the orange.
We eat the orange, and our bodies kickstart a chemical reaction in our stomachs, breaking down the potential energy in the glucose along with other energy-rich molecules. Chemical changes happen at a molecular level, releasing the potential energy in the bonds. A new substance called adenosine triphosphate (ATP) is created. ATP is an energy-carrying molecule found in the cells of all living things.
What Happens to Energy When Chemical Bonds Are Broken?
The broken bonds of chemical compounds release energy as new chemical bonds form, creating new substances and heat.
Those reactions that create more energy than was stored are called exothermic reactions. Burning methane in a power plant to heat our homes is an example. Methane is a hydrocarbon. When burned, it reacts with oxygen and produces carbon dioxide and water as byproducts. Methane’s carbon atoms recombine with oxygen to form carbon dioxide molecules while its hydrogen atoms pair up with oxygen to transform into water molecules.
Combustion breaks the bonds that tie methane’s original hydrogen and carbon bonds. The atoms look to form new bonds. Oxygen’s presence means water and carbon dioxide molecules form during combustion. Energy is released by these reactions; there is less energy stored in the new bonds comprised in the water and carbon dioxide molecules than was initially stored in the methane bonds.
This exothermic reaction means that burning methane is, chemically speaking, an excellent way to create heat. However, methane is a greenhouse gas and very damaging to the Earth’s atmosphere.
Where Is Chemical Energy Contained in a Compound?
Compounds contain chemical energy in the bonds that bind an atom together. We talk about a compound’s bond enthalpy or bond energy when we break these bonds.
Bond enthalpy is the amount of energy needed to break that bond when it’s in its gas state. This is called the heat content of a system.
How Many Types of Energy Are There?
Energy comes in many different forms with two main categories: stored energy (potential energy) and the energy of motion (kinetic energy).
Energy comes in many more forms:
- Nuclear energy provides energy thanks to nuclear fusion’s chemical reactions.
- Mechanical energy is the total energy sum of potential and kinetic energy.
- Chemical energy is stored energy in substances released by forming and breaking chemical bonds.
- Electrical energy comes from electrical charge flows and can be potential or kinetic energy.
- Radiant energy, or electromagnetic energy, is electromagnetic waves traveling through space from the sun or from light bulbs.
- Thermal energy is produced by rises in temperature and is also known as heat.
What Are 5 Examples of Chemical Energy?
There are many examples of chemical energy in our everyday lives. Here are a handful you’ll probably recognize:
- Food: Our bodies create chemical reactions to break down the chemical compounds in food to release energy.
- Propane: Heat and light result from burning propane, used for space heating, buses, cooking, and more.
- Car batteries: Chemicals store energy in battery cells which then convert to electrical energy to help run automobiles.
- Explosives: These store chemical energy. Explosions produce light and heat in gaseous forms, offering an example of how unstable compounds rearrange their bonds easily and quickly.
- Petroleum: Combustion engines cause heat and energy to be released by restructuring atoms and molecules.
How Do We Generate Power With Chemical Energy?
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Chemical energy is one of the pillars of our energy supply, producing heat, electricity, and powering transportation worldwide.
Burning fossil fuels produces steam to turn turbines that produce electricity. We also burn biomass, biodiesel, biofuels, and more products to the same end.
Our planes, lawnmowers, automobiles, and more machines run on fuels we burn. Batteries store chemical energy for later use.
With climate change upon us, solar panel technology has rapidly improved our ability to convert solar rays into chemical energy that we transform into electrical power.
Does a Phone Use Chemical Energy?
Almost everyone carries a little bit of chemical energy around with them every day in their cell phone. A phone’s battery stores chemical energy, which we charge with electricity. This electricity causes a chemical reaction inside the battery when we use the cell phone, pushing electrons around its circuits.
As we know, phone batteries run out. This occurs because the electrons have moved through the battery circuit to its negative end. Electrical charging pushes the electrons to the positive end of the battery so we can replicate the chemical reaction and use our phones again.
Is Wood a Source of Chemical Energy?
Wood in any form has chemical energy. It has potential chemical energy while it awaits burning, and chemical energy is released during burning, emitted as light and heat.
Burning wood in a traditional kitchen stove is an exothermic reaction that releases the wood’s potential energy as a form of heat, warming the stove and the kitchen.
Trees grow thanks to the sun’s energy. Some consider wood a renewable energy source because it can be regrown within our lifetimes. Wood classifies as a biomass fuel because it is energy from a plant or animal.
Where Is Chemical Energy Stored in Plants?
Plants store the sun’s solar energy as chemical energy in sugar (glucose) and produce oxygen thanks to photosynthesis. Glucose is present in the cells of leaves (called chloroplasts), which are full of chlorophyll to ease light absorption.
What Are the Disadvantages of Chemical Energy?
As we’ve discovered, much of the chemical energy we use comes from fossil fuels that are costly to mine and pollute the planet.
In 2020, some 79% of the United States’ energy production came from fossil fuels, coal, petroleum, and natural gas. Using vast quantities of fossil fuels releases carbon dioxide and other greenhouse gases into the atmosphere, accelerating global warming and climate change.
Even alternative energy sources like solar panels add to people’s carbon footprints. Minerals require mining, materials transportation, and ultimately, panels will need replacing and recycling. Wood extraction requires forest clearance, and biofuels require crops to grow.
Energy is not the only disadvantage of chemical energy, as we’ve seen with nuclear bombs. Chemical energy was at work when tens of thousands of people died as the United States dropped an atomic bomb on Hiroshima, Japan in 1945, and Nagasaki three days later.
Nuclear power plant accidents have polluted great stretches of the environment and killed many people. Infamous sites include Chernobyl in the former Soviet Union (considered the worst nuclear disaster in history), Fukushima Daiichi in Japan, and Three Mile Island in the United States. Nuclear waste requires storage that critics say adds damaging radiation to the local area.
Chemical Energy Plays a Role in Our Everyday Lives
We use chemical energy when we turn on the heater, enjoy a meal, or go for a drive.
This energy of breaking and forming bonds has become a simple and effective way to transport energy where it’s needed. Whether digging up coal from the Earth or firing up a propane BBQ grill, we are always using chemical energy. As such, we can be more mindful about how we use it.
For example, we could opt for a green energy plan that uses renewable energy sources. We could also incorporate more plant-based eating habits to help curb the negative impact meat production has on the environment.
Chemical energy has transformed life on the planet and will undoubtedly continue to do so. The vital question is now isn’t what is chemical energy, but how can we use it in the future in a sustainable, responsible way?
Brought to you by amigoenergy
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