Name: chemical reaction basics and equilibrium
Uploaded: 2023-06-23T15:38:43.000Z
Duration: 1 min 23 s
Channel: JoVE

K12 Standards

Louisiana Student Standards for Science

High School

Chemistry

Matter And Its Interactions

HS-PS1-2

Introduction to Chemical Reactions

化学反応とは、反応物と呼ばれる1つ以上の物質の原子が、化学結合を切断し、新しい結合を形成して生成物を生成することにより、原子の配置を変更するプロセスです。
エネルギーの正味の放出をもたらす反応はエクセルゴニックであり、エンダーゴニック反応はエネルギーの正味の吸収体です。
人体で起こる生化学反応は、タンパク質の合成、分解、多糖類の単糖への分解などの異化反応、またはATPのリン酸をグルコースに移動してグルコースリン酸を形成するなどの交換反応など、合成または同化のいずれかに分類されます。
多くの生化学反応では、反応を加速するための触媒として酵素を使用します。
すべての生化学反応は、順反応と逆反応が同じ速度で起こっているため、反応物と生成物の濃度の正味の変化が起こらない状態である平衡に向かって進行します。
生化学反応は、恒常性を維持し、成長や修復などの重要な機能を果たすためのエネルギーを提供します。

化学反応の導入

すべての化学反応は、反応物と呼ばれる1つ以上の物質が反応に入る一般的な用語から始まります。例えば、塩化ナトリウムの生産においては、ナトリウムイオンと塩化イオンが反応物です。化学反応によって生成される1つ以上の物質は生成物と呼ばれます。化学反応は、質量保存の法則に従います。これは、化学反応で物質を作成または破壊することはできないことを意味します。反応物の構成要素（原子数や元素）は、生成物にすべて存在しています。同様に、生成物には反応物に存在しないものはありません。 化学反応には、古い化学結合を切り、新しい化学結合を形成するために、精度と力の十分な確保が必要な十分なエネルギーが必要です。一般的に、動いている物質の任意の種類のエネルギーは運動エネルギーです。位置エネルギーまたは構成要素の配置や構造による物質のエネルギーを潜在エネルギーといいます。すべての原子は常に運動エネルギーを持っています。反応物の化学結合を切り、反応を開始するために必要なエネルギーは活性化エネルギーと呼ばれます。反応物の濃度と温度は、化学反応の速度に影響を与えることがあります。 化学方程式を書くための慣習は、反応の矢印の左側に反応物の式を、右側に生成物の式を配置することです。この慣習と「反応物」と「生成物」の定義により、化学反応は左から右へ進むことを示しています。しかし、可逆反応では、正方向（左から右）および逆方向（右から左）の両方で進行する場合があります。正反応と逆反応の速度が等しい場合、反応物および生成物の濃度は時間の経過とともに一定であり、系は平衡状態にあります。平衡系の反応物と生成物の相対濃度は非常に異なる場合があります。一部の系は平衡時にほとんど生成物を含み、一部はほとんど反応物を含み、一部は両方の存在量がかなり多いです。 例えば、人間の血液では、過剰な水素イオン（H+）が重炭酸塩イオン（HCO3-）に結合し、炭酸を形成し、平衡状態を形成します。このシステムに炭酸を追加すると、一部は重炭酸塩と水素イオンに戻る代わりに、炭酸は二酸化炭素ガスとして（呼気を通じて）体外へ排出されます。これによって、質量作用の法則により、反応は右へ進みます。これらの反応は、血液の恒常性を維持するために重要です。

 このテキストは、<a href="https://openstax.org/books/anatomy-and-physiology-2e/pages/2-3-chemical-reactions">Openstax, Anatomy and Physiology 2e, Section 2.3: Chemical Reactions</a>、<a href="https://openstax.org/books/chemistry-2e/pages/13-1-chemical-equilibria">Openstax, Chemistry 2e, Section 13.1: Chemical equilibria</a> と <a href="https://openstax.org/books/biology-2e/pages/2-1-atoms-isotopes-ions-and-molecules-the-building-blocks">Openstax, Biology 2e, Section 2.1: Atoms, Isotopes, Ions and Molecules: The Building Blocks</a>

すべての化学反応は、反応物、つまり反応に入る1つ以上の物質の総称から始まります。ナトリウムイオンと塩化物イオン、例えば...

Education

JoVE Core

Anatomy and Physiology

解剖生理学

Unit 1

ユニット1

Fundamentals of Chemistry

化学の基礎

KEY TERMS AND CONCEPTS

主要用語と概念

chemical reaction basics and equilibrium

Chemical reactions start with reactants and end with products. Reactants are the substances that enter a reaction, and products are the new substances that form. For example, sodium and chloride ions are the reactants in the formation of table salt.

Chemical reactions follow the law of conservation of mass. Matter is not created or destroyed during the reaction. That means the atoms and elements in the reactants are still present in the products, and nothing new appears in the products that was not already in the reactants.

Energy is needed to start many reactions. Collisions between particles must happen with enough force and precision to break old chemical bonds and form new ones. Kinetic energy is the energy of motion, while potential energy is the energy that comes from position or structure. Atoms always have kinetic energy because they are always moving. The energy needed to break the bonds of the reactants and begin the reaction is called activation energy.

Reaction rate can change with concentration and temperature. Chemical equations show reactants on the left side of an arrow and products on the right side. This convention shows the reaction moving from left to right. Some reactions are reversible, so they can also move from right to left.

In a reversible reaction, equilibrium happens when the forward and reverse reaction rates are equal. At that point, the concentrations of reactants and products stay constant over time. Some equilibrium systems contain mostly products, some contain mostly reactants, and some contain significant amounts of both. In human blood, excess hydrogen ions bind to bicarbonate ions to form carbonic acid. If carbonic acid is added, some of it changes back into bicarbonate and hydrogen ions.

Biological reactions often do not reach equilibrium because the concentrations of reactants and products keep changing. In many cases, one reaction’s product becomes a reactant for another reaction. In the blood example, carbonic acid can also leave the body as carbon dioxide gas during exhalation instead of changing back. This pulls the reaction to the right by the law of mass action and helps maintain homeostasis in the blood.

Chemical Reaction Basics and Equilibrium

what is matter?

Matter, Mass, and Weight Basics

Matter is the substance that makes up the universe, from a grain of sand to a star. Scientists define matter as anything that occupies space and has mass. Mass is the amount of matter in an object, while weight depends on gravity. Mass stays the same whether an object is on Earth or in the zero-gravity environment of outer space. Weight changes when gravity changes. An object weighs more where gravity is stronger and less where gravity is weaker. A piece of cheese that weighs a pound on Earth...

the periodic table and organismal elements

the-periodic-table-and-organismal-elements

Organismal Elements in the Periodic Table

The periodic table helps identify the elements that make up living organisms. Biology groups these as organismal elements because they are the chemical building blocks of life. These elements are found in different amounts in the body. Some are present in large quantities, while others are needed only in small amounts. The video connects the periodic table to the elements that organisms actually use. Understanding organismal elements helps students link chemistry to biology. It shows how...

atomic structure

From Atomos to the Modern Atom

Atoms are the tiny building blocks of matter, and ideas about them go back to the Greek philosopher Democritus. He suggested that everything on Earth is made of atomos, a Greek word meaning "indivisible." That idea later led to the modern word atom. In the 19th century, John Dalton developed an atomic theory that is still largely correct today. He proposed five key ideas. All matter is made of tiny particles called atoms. Atoms of the same element are alike, and atoms of different elements are...

chemical symbols

Chemical Symbols and Element Names

Chemical symbols are short abbreviations that stand for an element or a single atom of that element. Mercury, for example, has the symbol Hg. The same symbol can point to one atom of mercury in the microscopic domain or to a sample labeled as many atoms of mercury in the macroscopic domain. Many symbols come from the element’s common name. Others are shortened from a name in another language. Most chemical symbols use one or two letters. For a few elements with atomic numbers above 112,...

atomic number and mass number

Atomic Identity, Mass, and Isotopes

Atomic identity depends on the number of protons in the nucleus, and mass depends on protons and neutrons together. The number of protons is the atomic number, or Z. It defines the element. For example, any atom with six protons is carbon, no matter how many neutrons or electrons it has. In a neutral atom, the number of protons equals the number of electrons. Because of that, the atomic number also tells you the number of electrons in the atom. The total number of protons and neutrons is...

atomic weight

Atomic Mass and Mole Calculations

Atomic mass and mole calculations help explain how much matter is in atoms and compounds. Protons and neutrons have about the same mass, about 1.67 × 10 -24 grams. Scientists define that mass as one atomic mass unit, or amu, also called one Dalton. Electrons are much lighter than protons. They weigh only 9.11 × 10 -28 grams, or about 1/1800 of an atomic mass unit. Because of that small mass, electrons do not add much to an element’s overall atomic mass. When chemists calculate atomic mass,...

isotopes and radioisotopes

Radioisotopes in Medicine and Imaging

Radioisotopes are unstable isotopes that can be used to study the body and treat disease. An isotope is an atom of the same element that has a different mass because it contains a different number of neutrons. It still has the same number of protons, so it remains chemically identical. English chemist Frederick Soddy explained this idea in the early 1900s and later received the Nobel Prize in Chemistry in 1921. Some isotopes have more neutrons than usual and are called heavy isotopes. These...

electron behavior

Electron Shells and Discovery

Electrons are negatively charged subatomic particles that stay near the positively charged nucleus of an atom. They occupy spaces linked to energy levels called shells. They are also arranged into subshells and orbitals within each shell. An electron’s shell shows its general energy level. Electrons closer to the nucleus have less energy, while electrons farther away have more energy. The outer shells have more space, so they can hold more electrons than the inner shells. Subshells describe...

introduction to chemical bonds

How Atoms Bond to Reach Stability

Atoms bond to become more stable, and their outermost electrons play the biggest role in that process. The inner electron shell can hold two electrons. The next two shells can each hold eight electrons. This is called the octet rule. It states that, except for the innermost shell, atoms are most stable when their valence shell, or outer shell, has eight electrons. When atoms do not have enough electrons to fill that outer shell, they form chemical bonds with other atoms. A chemical bond is the...

ionic bonds

Ionic Bonds and Charge Transfer

Ionic bonds form when atoms transfer electrons and become charged particles. A positive ion and a negative ion attract each other because opposite charges pull together. This type of bonding helps explain how some substances are held together. In many cases, an atom loses one or more electrons, while another atom gains them. The atom that loses electrons becomes a cation, which is a positively charged ion. The atom that gains electrons becomes an anion, which is a negatively charged ion. The...

covalent bonds

Polar and Nonpolar Covalent Bonds

Covalent bonds form when atoms share electrons to fill their valence shells. The way those shared electrons are pulled depends on electronegativity, which is an atom's tendency to attract electrons in a bond. That difference also helps explain why some molecules are polar and others are nonpolar. Atoms with similar electronegativities form nonpolar covalent bonds. In these bonds, electrons are shared equally, so there is no charge across the molecule. When two atoms have different...

hydrogen bonds

Hydrogen Bonding and DNA Stability

Hydrogen bonding helps explain why some molecules stick together more strongly than others. A hydrogen bond forms when a weakly positive hydrogen atom, already bonded to an electronegative atom, is attracted to another electronegative atom on a nearby polar molecule. Common examples include water, hydrogen fluoride, and ammonia. This attraction happens because hydrogen has a much lower electronegativity than atoms such as fluorine, oxygen, and nitrogen. The electronegativity difference, along...

ions, molecules, and compounds

Atomic Charges, Bonds, and Compounds

Atoms can gain or lose electrons during chemical reactions and become ions. An ion is an atom with an electrical charge. This charge is positive or negative, and it often helps the atom reach a full valence shell. Some atoms are more likely to donate electrons, while others are more likely to accept them. Potassium is one example. It has atomic number 19 and one electron in its valence shell, so it is likely to donate that electron and become a slightly positive ion called a cation. Fluorine...

states of matter

Solids, Liquids, Gases, and Plasma

Solids, liquids, gases, and plasma are the main forms of matter described here. Solids are rigid and keep a definite shape. Liquids flow and take the shape of their container, although gravity gives the surface a flat or slightly curved top. Solids and liquids also have volumes that stay nearly the same even when pressure changes. Gases behave differently from solids and liquids. A gas takes both the shape and the volume of its container. In matter with this behavior, the particles are far...

colloids and suspensions

Suspensions, Sedimentation, and Colloids

Suspensions and colloids are two common kinds of mixtures seen in everyday life. Mud and water, flour and water, and tempera paint are suspensions. These mixtures are heterogeneous, which means their particles are not spread out evenly. The particles are relatively large and can be seen with the naked eye or a magnifying glass. Suspension particles make mixtures cloudy, and they settle out after mixing. The settling of particles in a suspension is called sedimentation. A blood test can measure...

introduction to chemical reactions

Chemical reactions start with reactants and end with products. Reactants are the substances that enter a reaction, and products are the new substances that form. For example, sodium and chloride ions are the reactants in the formation of table salt. Chemical reactions follow the law of conservation of mass. Matter is not created or destroyed during the reaction. That means the atoms and elements in the reactants are still present in the products, and nothing new appears in the products that...

types of chemical reactions: anabolic and catabolic

types-of-chemical-reactions-anabolic-and-catabolic

Anabolism, Catabolism, and ATP Use

Anabolism and catabolism are the two main kinds of metabolic reactions in the body. Metabolism is the total set of anabolic and catabolic reactions that keep life running. These reactions follow the first law of thermodynamics, which says energy cannot be created or destroyed. It can only change form. Anabolism builds larger, more complex molecules from smaller ones. These anabolic, or biosynthesis, reactions need energy in the form of ATP. They join monosaccharides into polysaccharides, fatty...

types of chemical reactions: exchange and reversible

types-of-chemical-reactions-exchange-and-reversible

Electron Transfer and Chemical Equilibrium

Exchange reactions and reversible reactions are two important ideas in chemistry. In an exchange reaction, synthesis and decomposition happen at the same time. Chemical bonds are both formed and broken. These reactions can absorb chemical energy, store it, and release it. A special type of exchange reaction is the oxidation-reduction reaction, or redox reaction. In a redox reaction, electrons move from one compound to another. The electrons often come from hydrogen atoms, which contain one...

energy transfer in chemical reactions

Chemical Energy and Reaction Types

Chemical reactions depend on energy transfer, chemical bonds, and the way matter collides. A reaction needs enough energy for particles to meet with the right force and precision. That energy can break old bonds and help form new ones. Kinetic energy is the energy of motion. A person lifting a brick uses kinetic energy to move the brick into place on a wall. Once the wall is built, it stores potential energy, which is the energy of position or structure. If the wall falls, that stored energy...

factors influencing the rate of chemical reactions

factors-influencing-the-rate-of-chemical-reactions

Chemical Reaction Rates and Catalysts

Chemical reaction rates depend on how often particles collide and whether those collisions have enough energy to start a reaction. That starting energy is called activation energy. Factors that affect reaction rate either lower that energy or make successful collisions more likely. Concentration and pressure can speed reactions up because they put more particles in the same space. When more particles are present, they are more likely to bump into one another. Chemists can also increase...

acids, bases and neutralization reactions

How pH Affects Cells and Digestion

Acids, bases, and pH help control how cells and body systems work. In biology, pH can strongly affect enzymes, proteins, and nucleic acids. Enzymes work best within a certain pH range, and pH changes can alter their structure or denature them, which changes how they function. Acids release hydrogen ions, or H+, in solution. A hydrogen ion is a proton, so it is very reactive in chemical reactions. Strong acids release all of their H+ in water and ionize completely. Hydrochloric acid (HCl) is a...

key terms and concepts

Learn how reactants become products, how mass is conserved, what activation energy means, and how reversible reactions reach equilibrium in blood.

Chemical Reaction Basics and Equilibrium | JoVE K12

anatomy and physiology

JoVE Core 解剖学と生理学では、人体の解剖学的および生理学的な詳細を、包括的で明確で魅力的なビデオ アニメーションで紹介します。このレッスン集は、人体の構造、コンポーネント、機能、要件に焦点を当てています。この知識を実際の医療および研究現場で応用することを実証する科学者による実際のビデオによって補完されています。

HS-PS1-4

HS-PS1-5

HS-PS1-7

Tennessee Academic Standards

Matter and Its Interactions

CHEM1.PS1.4

Energy

CHEM1.PS3.3

Minnesota Academic Standards in Science

9-12

2.2.1 9C.1.2.1.2

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

C-PS1-2

C-PS1-4

C-PS1-5

C-PS1-6

C-PS1-7

Georgia Standards of Excellence

Physical Science

SPS3.

Chemical Reaction

The Periodic Table

As early chemists discovered more elements, they realized that various elements could be grouped by their similar chemical behaviors. One such grouping ...

Periodic Classification of the Elements

The periodic table arranges atoms based on increasing atomic number so that elements with the same chemical properties recur periodically. When their ...

The Periodic Table And Organismal Elements

Atomic Structure

The Greek philosopher Democritus proposed that everything on Earth is made up of tiny particles called atomos, Greek for &#34;indivisible,&#34; from which ...

Electron Configurations

Electron configurations and orbital diagrams can be determined by applying the Aufbau principle (each added electron occupies the subshell of lowest ...

Electronic Structure of Atoms


An atom comprises protons and neutrons, which are contained inside the dense, central&#160;core called the nucleus, with electrons present around the ...

electron-configuration-of-multielectron-atoms

Electron Configuration of Multielectron Atoms

The alkali metal sodium (atomic number 11) has one more electron than the neon atom. This electron must go into the lowest-energy subshell available, the ...

atomic-radii-and-effective-nuclear-charge

Atomic Radii and Effective Nuclear Charge

The elements in groups of the periodic table exhibit similar chemical behavior. This similarity occurs because the members of a group have the same number ...

The Aufbau Principle and Hund's Rule

To determine the electron configuration for any particular atom, we can build the structures in the order of atomic numbers. Beginning with hydrogen, and ...

Coulomb's Law

Experiments with electric charges have shown that if two objects each have an electric charge, they exert an electric force on each other. The magnitude ...

Electric Charges

From lightning during thunderstorms to electronic devices, the phenomenon of electromagnetism is all around us. The electromagnetic force is one of the ...

sources-and-properties-of-electric-charge

Sources and Properties of Electric Charge

All objects we see around us consist of atoms, which combine to form molecules. The lightest element in the universe is hydrogen, and a hydrogen atom ...

Types of Forces

In most situations, forces can be grouped into two categories: contact forces and field forces.&#160; Contact forces occur as a result of direct physical ...

Electric Fields

Source: Yong P. Chen, PhD, Department of Physics &#38; Astronomy, College of Science, Purdue University, West Lafayette, IN
An electric field is generated ...

Intermolecular Forces

Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions ...

Van der Waals Interactions

Atoms and molecules interact with each other through intermolecular forces. These electrostatic forces arise from attractive or repulsive interactions ...

Chemical Bonds


Atoms participate in a chemical bond formation&#160;to acquire a completed valence-shell electron configuration similar to that of the noble gas nearest ...

Electron Behavior

Electrons are negatively charged subatomic particles attracted to and orbit around the positively-charged nucleus of an atom. They reside in spaces ...

Subatomic Particles

Dalton was only partially correct about the particles that make up matter. All matter is composed of atoms, and atoms are composed of three smaller ...

Ions and Ionic Charges

In ordinary chemical reactions, the nucleus &mdash; which contains the protons and neutrons of each atom and thus identifies the element &mdash; remains ...

Use the periodic table as a model to predict the relative properties of elements based on the patterns of electrons in the outermost energy level and the composition of the nucleus of atoms.  Clarification Statement: Chemistry: Examples of properties that could be predicted from patterns could include reactivity of metals, types of bonds formed, numbers of bonds formed, atomic radius, atomic mass, or reactions with oxygen. Emphasis is on main group elements and qualitative understanding of the relative trends of ionization energy and electronegativity.

HS-PS1-1

Properties of Transition Metals

Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3&#8211;12 are ...

The Atomic Theory of Matter

The earliest recorded discussion of the basic structure of matter comes from ancient Greek philosophers. Leucippus and Democritus argued that all matter ...

Chemical Reactions

A chemical reaction is a process by which the bonds in the atoms of substances are rearranged to generate new substances. Matter cannot be created or ...

Chemical Equations

Chemical equations represent the identities and relative quantities of substances involved in a chemical reaction. The substances undergoing reaction are ...

All chemical reactions begin with a reactant, the general term for one or more substances entering the reaction. Sodium and chloride ions, for example, ...

Temperature Dependence on Reaction Rate

The Collision Theory
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. ...

stoichiometry-product-yield-and-limiting-reactants

Stoichiometry, Product Yield, and Limiting Reactants

Source: Smaa Koraym at Johns Hopkins University, MD, USA

	Preparation of 25% v/v Ethylenediamine in Deionized WaterExpand
	Here, we show the laboratory ...

physical-and-chemical-properties-of-matter

Physical and Chemical Properties of Matter

The characteristics that enable us to distinguish one substance from another are called properties.

Physical Properties of Matter

A physical property is ...

Dynamic Equilibrium

A reversible chemical reaction represents a chemical process that proceeds in both forward (left to right) and reverse (right to left) directions. When ...

Construct and revise an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties.  Clarification Statement: Chemistry: Examples of chemical reactions could include the reaction of sodium and chlorine, carbon and oxygen, or carbon and hydrogen. Reaction classification aids in the prediction of products (e.g. synthesis, decomposition, single displacement, double displacement, and acid-base).

Intermolecular vs Intramolecular Forces

Intermolecular forces (IMF) are electrostatic attractions arising from charge-charge interactions between molecules. The strength of the intermolecular ...

comparison-between-electrical-and-gravitational-forces

Comparison Between Electrical And Gravitational Forces

There are four fundamental forces in nature: the gravitational force, the electromagnetic force, the strong nuclear force, and the weak nuclear force. To ...

intermolecular-forces-and-physical-properties

Intermolecular Forces and Physical Properties



Intermolecular forces are attractive forces that exist between molecules. They dictate several bulk properties, such as melting points, boiling points, ...

electric-field-of-two-equal-and-opposite-charges

Electric Field of Two Equal and Opposite Charges

Atoms generally contain the same number of positively and negatively charged particles, protons, and electrons. Hence, they are electrically neutral. ...

Electric Field

Consider two point charges, each exerting Coulomb force on the other. It is possible to describe the Coulomb interaction via an intermediate step by ...

Ionic Bonding and Electron Transfer

Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence ...

Electric Dipoles and Dipole Moment

Consider two charges of equal magnitude but opposite signs. If they cannot be separated by an external electric field, the system is called a permanent ...

Plan and conduct an investigation to gather evidence to compare the structure of substances at the macroscale to infer the strength of electrical forces between particles.  Clarification Statement: Emphasis is on understanding the strengths of forces between particles, not on naming specific intermolecular forces (such as dipole-dipole). Examples of particles could include ions, atoms, molecules, and network solids (such as graphite). Examples of macro-properties of substances could include the melting point and boiling point, vapor pressure, and surface tension.

HS-PS1-3

Chemical Reaction Basics and Equilibrium

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