Chapter 12 Basics of Chemistry 1

Learning Objectives List the difference between organic and inorganic chemistry. Categorize and give examples of different substances for each of the different states of matter: solid, liquid, and gas. Summarize, in your own words, oxidation–reduction (redox) reactions. (continues) 2

Learning Objectives (continued) Define the differences between pure substances and physical mixtures. Evaluate the differences among solutions, suspensions, and emulsions. Explain what pH is and how the pH scale works. WHY STUDY CHEMISTRY? Without an understanding of basic chemistry you would not be able to use professional products effectively and safely. Every product used in the salon and in cosmetology services contains some type of chemical. With an understanding of chemistry, you will be able to troubleshoot and solve common problems you may encounter with chemical services.

Introduction Most cosmetology services depend on the use of chemicals. Studying the basics of chemistry means that you will have the knowledge you need to understand the products that you are using in the salon to give your clients the professional services they deserve. INTRODUCTION • Most cosmetology services depend on the use of chemicals. • Studying the basics of chemistry means that you will have the knowledge you need to understand the products that you are using in the salon to give your clients the professional services they deserve.

LESSON ACTIVITY 1 Explain to the students that you are continuing the unit of study of cosmetology sciences and that you will be covering chemistry in detail in the next few lessons. Divide students into small groups. Ask them to discuss and record everything they did between waking up this morning and arriving for school, beginning with the alarm clock going off. After they have completed their list, have them indicate which tasks used chemistry. For example: brushed teeth—chemistry (in the water and toothpaste); took shower—chemistry (water, soap, shampoo, conditioner, etc.). After they have completed their group assignment, conduct a discussion about how during their first two hours or so of being awake today nearly every aspect of their lives was affected by chemistry. 5

Recognize How the Science of Chemistry Influences Cosmetology The science that deals with the composition, structures, and properties of matter and how matter changes under different conditions RECOGNIZE HOW THE SCIENCE OF CHEMISTRY INFLUENCES COSMETOLOGY Chemistry is the science that deals with the composition, structures, and properties of matter and how matter changes under different conditions. 6

Organic Chemistry The study of substances that contain carbon. All living or formerly living things contain carbon. All hair color products, chemical texturizers, shampoos, conditioners, styling aids, nail enhancements, and skin care products are organic chemicals. ORGANIC CHEMISTRY Organic chemistry is the study of substances that contain the element carbon. All living things or things that were once alive, whether they are plants or animals, contain carbon. All hair color products, chemical texturizers, shampoos, conditioners, styling aids, nail enhancements, and skin care products are organic chemicals. 7

Inorganic Chemistry The study of substances that do not contain the element carbon but may contain the element hydrogen Metals, minerals, glass, water, air, pure water, oxygen, hydrogen peroxide, hydroxide hair relaxers, titanium dioxide, and zinc oxide in sun protection creams are inorganic substances. INORGANIC CHEMISTRY Inorganic chemistry is thestudy of substances that do not contain the element carbon but may contain the element hydrogen. Metals, minerals, glass, water, air, pure water, oxygen, hydrogen peroxide, hydroxide hair relaxers, titanium dioxide, and zinc oxide in sun protection creams are inorganic substances. 8

Define Matter Matter Anything that occupies space Has physical chemical properties Exists in the form of a solid, liquid, or gas DEFINE MATTER Any substance that occupies space and has mass (weight). All matter has physical and chemical properties and exists in the form of a solid, liquid, or gas. Since matter is made from chemicals, everything made out of matter is a chemical. 9

Elements Simplest form of matter Cannot be reduced without loss of identity At least 98 naturally occurring Identified by a letter symbol ELEMENTS An element is the simplest form of chemical matter. It cannot be broken down into a simpler substance without a loss of identity. All matter in the universe is made up of these elements and they have their own distinct physical and chemical properties. Each element is identified by a letter symbol, such as O for oxygen, C for carbon, H for hydrogen, N for nitrogen, and S for sulfur. Composed of a single part or unit. Cannot be reduced to a SIMPLER SUBSTANCE, at least not without loss of identity. 98 naturally occurring elements. 10

Atoms and Molecules Atom – the basic unit of matter Molecules – the chemical combination of two or more atoms Elemental molecule Compound molecule ATOMS AND MOLECULES Atoms The basic unit of matter with a nucleus at the center surrounded by negatively charged electrons (E) that move around the nucleus in orbits. The nucleus consists of protons (P) (subatomic particles with a positive charge) and neutrons (N) (subatomic particles with no charge) and the number of protons determines the element. Atoms cannot be divided into simpler substances by ordinary chemical means. Molecules A chemical combination of two or more atoms in definite (fixed) proportions. For example, water is made from hydrogen and oxygen. Elemental molecule A chemical combination of atoms of the same element, in fixed proportions; the air we breathe is an elemental molecule: O2. The ozone in the atmosphere is an elemental molecule: O3. Compound molecule These are chemical compounds of two or more atoms of different elements, in fixed proportions. Sodium Chloride (NaCl), or common table salt, is a compound molecule that contains one atom of sodium (Na) and one atom of chlorine (Cl). 11

States of Matter 12 STATES OF MATTER All matter exists in three different physical forms: solid, liquid, or gas. Matter takes on one of these forms or states depending on its temperature. Solids: Have a definite shape, volume, and weight (ice) Liquids: Have a definite volume and weight but not a definite shape (water takes on the shape of its container) Gases: Do not have a definite volume or shape Neon and argon are two different gases. Vapor: A liquid that has evaporated into a gas-like state. Vapors can return to being a liquid when they cool to room temperature, unlike a gas. Steam is an example of a vapor. Vapors are not a unique state of matter; they are liquids that have undergone a physical change. 12

Physical and Chemical Properties of Matter Physical properties – determined without a chemical reaction (color, odor, weight, density) Chemical properties – determined with a chemical reaction (change identity — rusting iron, burning wood) PHYSICAL AND CHEMICAL PROPERTIES OF MATTER Physical properties: Are characteristics that can be determined without a chemical reaction and that do not involve a chemical change in the substance. Include color, solubility, odor, density, melting point, boiling point, hardness, and glossiness. Chemical properties: Are characteristics that can only be determined by a chemical reaction and a chemical change in the substance. Examples include the ability of iron to rust, wood to burn, or hair to change color through the use of haircolor and hydrogen peroxide. 13

Physical and Chemical Changes Physical Change The form is changed without becoming a new substance. Example: Solid ice melts and becomes water. PHYSICAL AND CHEMICAL CHANGES Matter can be changed in two different ways. Physical forces cause physical changes and chemical reactions cause chemical changes.  A physical change changes the form without forming a new substance. Example: solid ice melts and becomes water—there are no new chemicals, just a different form. (continues) 14

Physical and Chemical Changes (continued) A change in the chemical composition or makeup of a substance Example: Burning wood turns into ashes PHYSICAL AND CHEMICAL CHANGES (continued) A chemical change is a change in a substance’s chemical composition. A chemical change creates new substances with different properties. Examples: iron to rust; wood into ashes; the oxidation of haircolor; or the polymerization of artificial nail enhancements. 15

Oxidation Oxidation A chemical reaction that combines a substance with oxygen to produce an oxide Example: Wood turns into charcoal after it has burned. OXIDATION Oxidation is a chemical reaction that combines a substance with oxygen to produce an oxide. Such as the oxidation of melanin pigments in hair by hydrogen peroxide in lightening processes. 16

Oxidation-Reduction Also known as redox A chemical reaction in which the oxidizing agent is reduced (by losing oxygen) and the reducing agent is oxidized (by gaining oxygen) OXIDATION-REDUCTION (REDOX) Also known as redox A chemical reaction in which oxidation and reduction take place at the same time. 17

Oxidizing Agent A substance that releases oxygen Hydrogen peroxide (an oxidizing agent) can be thought of as water with an extra atom of oxygen. OXIDIZING AGENT An oxidizing agent is a substance that releases oxygen Hydrogen peroxide (an oxidizing agent) can be thought of as water with an extra atom of oxygen. 18

Reducing Agent A substance that adds hydrogen to a chemical compound or subtracts oxygen from the compound REDUCING AGENT A reducing agent is a substance that adds hydrogen to a chemical compound or subtracts oxygen from the compound. 19

Exothermic Reaction and Combustion Exothermic reaction – a chemical reaction when heat is released Combustion – rapid oxidation of a substance accompanied by the production of heat and light EXOTHERMIC REACTION AND COMBUSTION Exothermic reaction A chemical reaction in which heat is released. An example of an exothermic reaction is a nail product that hardens (polymerizes) to create nail enhancements. Combustion The rapid oxidation of a substance accompanied by the production of heat and light

Pure Substances and Physical Mixtures Pure substances – distinct properties Physical mixtures – elements combined physically PURE SUBSTANCES AND PHYSICAL MIXTURES Pure substances A chemical combination of matter in definite (fixed) proportions. Pure substances have unique properties. Aluminum foil is an example of a pure substance. It has only atoms of the element aluminum. Physical mixtures Physical combination of matter in any proportion. T he properties of a physical mixture are the combined properties of the substances in the mixture. Salt water is a physical mixture of salt and water in any proportion. 21

Solutions, Suspensions, and Emulsions Solution – a blend of two or more liquids or a solid dissolved in a liquid Solute – the dissolved substance in a solution Solvent – the substance that dissolves another substance to form a solution with no change in chemical composition SOLUTIONS, SUSPENSIONS, AND EMULSIONS Solutions, suspensions, and emulsions are all physical mixtures. Solution: A stable physical mixture of two or more substances in a solvent. Solute: The dissolved substance in a solution. Solvent: The substance, usually liquid, which dissolves another substance to form a solution, with no change in chemical composition. For example, when sugar is dissolved in hot water, the sugar (a solid) is the solute and the water (liquid) is the solvent. Water is the universal solvent. 22

Solutions and Suspensions Miscible liquids – mutually soluble Immiscible liquids – not capable of being mixed Suspension – unstable physical mixtures of undissolved particles in a liquid SOLUTIONS AND SUSPENSIONS Miscible liquids: Are mutually soluble, meaning that they can be mixed together to form clear solutions. Water and alcohol are examples of miscible liquids as in a nail polish remover. When these substances are mixed together, they will stay mixed, forming a solution. Immiscible liquids: Not capable of being mixed to form stable solutions (for example, oil and water). Suspension: Are unstable physical mixtures of undissolved particles in a liquid. 23

Emulsions and Emulsifiers Emulsion – mixture of two or more immiscible substances plus a special ingredient called an emulsifier Emulsifier – ingredient that brings two normally incompatible materials together and binds them into a uniform and fairly stable blend EMULSIONS AND EMULSIFIERS Emulsion: An unstable physical mixture of two or more immiscible substances (substances that normally will not stay blended) plus a special ingredient called an emulsifier. Emulsifier: An ingredient that brings two normally incompatible materials together and binds them into a uniform and fairly stable blend. Emulsions are considered to be a special type of suspension because they can separate, but the separation usually happens very slowly over a long period of time. 24

Surfactants Hydrophilic – water loving Lipophilic – oil loving Surfactant – joins water and oil Oil-in-water emulsion Water-in-oil emulsion SURFACTANTS Surfactants: Substances that allow oil and water to mix, or emulsify. They are one type of emulsifier. The term surfactant is a contraction for surface active agents—substances that allow oil and water to mix, or emulsify. Head of the surfactant: Hydrophilic, or water-loving, and dissolves in water. Tail of the surfactant: Lipophilic, or oil-loving, and dissolves in oil. Oil-in-water emulsion: Oil droplets are emulsified in water. The droplets of oil are surrounded by surfactant molecules with their lipophilic tails pointing in and their hydrophilic heads pointing out. Tiny oil droplets form the internal portion of each O/W emulsion because the oil is completely surrounded by water. Water-in-oil emulsion: Water droplets are emulsified in oil. The droplets of water are surrounded by surfactants with their hydrophilic heads pointing in and their lipophilic tails pointing out. Tiny droplets of water form the internal portion of a W/O emulsion because the water is completely surrounded by oil. 25

Differences Among Solutions, Suspensions, and Emulsions 26

LESSON ACTIVITY 2 Have students perform the oil and water activity found in the textbook. Pour some water into a glass and then add a little cooking oil (or other oil). What happens? Stir the water briskly with a spoon and observe for a minute or two. What does the oil do? 27

Other Physical Mixtures Ointments – semisolids made with any combination of petrolatum, oil, and wax Powders – physical mixture of two solids OTHER PHYSICAL MIXTURES Ointments, pastes, pomades, and styling waxes are semisolid mixtures made with any combination of petrolatum (petroleum jelly), oil, and wax. Powders: Physical mixture of one or more types of solids. Off-the-scalp, powdered hair lighteners are physical mixtures. These mixtures may separate during shipping and storage and should be thoroughly mixed by shaking the container before each use. 28

Common Chemical Product Ingredients Volatile alcohols Alkanolamines Ammonia Glycerin Silicones Volatile organic compounds COMMON CHEMICAL PRODUCT INGREDIENTS Volatile alcohols evaporate easily; examples are isopropyl alcohol (rubbing alcohol) and ethyl alcohol (hair spray and alcoholic beverages). Alkanolamines are alkaline substances used to neutralize acids or raise the pH of many hair products. Often used in place of ammonia. Ammonia Colorless with a pungent odor Composed of nitrogen and hydrogen; in a water solution, it is called ammonia water. Used to raise the pH (potential hydrogen) in permanent waving, haircoloring, and lightening substances. Raising the pH softens and swells the cuticle, allowing solution to penetrate the hair shaft. Glycerin Sweet, colorless, oily substance; used as a solvent and moisturizer Silicone is a special type of oil used in hair conditioners, water-resistant lubricants for the skin, and nail polish dryers. They are less greasy than many other oils and can impart a silky, smooth feel to skin and give shine to hair. Volatile organic compounds are compounds that contain carbon (organic) and evaporate very easily (volatile). The most common VOC used in hair sprays is ethyl alcohol. 29

Understand Potential Hydrogen (pH) and How it Affects Hair, Skin, and Nails The small p represents a quantity; the capital H represents the hydrogen ion Ion – atom or molecule that carries an electrical charge Ionization – temporary separation of a substance into ions Anion – ion with a negative electrical charge Cation – ion with a positive electrical charge UNDERSTAND POTENTIAL HYDROGEN (pH) AND HOW IT AFFECTS HAIR, SKIN, AND NAILS An ion is an atom or molecule that carries an electrical charge. Ionization is the separation of an atom or molecule into positive and negative ions. An anion is an ion with a negative electrical charge. An cation is an ion with a positive electrical charge. 30

Water and pH In pure water, some of the water molecules naturally ionize into hydrogen ions and some into hydroxide ions. The pH scale measures those ions. Hydrogen ion (H+) is acidic. Hydroxide ion (OH-) is alkaline. WATER AND pH In pure water, some of the water molecules naturally ionize into hydrogen ions and some into hydroxide ions. The pH scale measures those ions. The hydrogen ion (H+) is acidic. The hydroxide ion (OH-) is alkaline. Only aqueous solutions have pH. Nonaqueous solutions (oil and alcohol) do not have pH. Without water, there is no pH. Pure water contains the same number of hydrogen ions as hydroxide ions. It is neutral, being 50 percent acidic and 50 percent alkaline. 31

The pH Scale pH: potential hydrogen – Scale: 0 – 14 – pH of 7 is neutral Logarithm – multiples of ten THE pH SCALE The abbreviation used for potential hydrogen. A measure of the acidity and alkalinity of a substance. A scale of 0 to 14 indicates a neutral solution Below 7 indicates an acidic solution. Above 7 indicates an alkaline solution. Logarithm Means multiples of ten; the pH scale is logarithmic because a change of one whole number represents a tenfold change in pH. A change of two whole numbers represents a change of 10 times 10 (or a one-hundredfold change). 32

Acids and Alkalis All acids owe their chemical reactivity to the hydrogen ion. Acids have a pH below 7.0. Alpha hydroxy acids (AHAs) Thioglycolic acid Glycolic acid ACIDS AND ALKALIS All acids owe their chemical reactivity to the hydrogen ion. Acids have a pH below 7.0. Alpha hydroxy acids are derived from plants (mostly fruit), are examples of acids often used in salons to exfoliate the skin and to help adjust the pH of a lotion, conditioner, or cream. Thioglycolic acid is a colorless liquid or white crystals with a strong unpleasant odor that is used in permanent waving solutions to contract and close the hair cuticle. Glycolic acid is an alpha hydroxyl acid used in exfoliation and to lower pH of products. (continues) 33

Acids and Alkalis (continued) Alkalis (base) owe their chemical relativity to the hydroxide ion (OH-). Alkalis have a pH above 7. Feel slippery and soapy on the skin. Sodium hydroxide also known as lye, is used in chemical hair relaxers, callous softeners, and drain cleaners. ACIDS AND ALKALIS (continued) Alkalis Owe their chemical relativity to the hydroxide ion (OH-) Term is interchangeable with base. pH above 7. Feel slippery and soapy on the skin. Sodium hydroxide, also known as lye, is used in chemical hair relaxers, callous softeners, and drain cleaners. 34

LESSON ACTIVITY 3 Divide students into groups and have them use the Internet to research the wet line products used in the school to find their pH. If the information is not available online, contact the manufacturers. Once completed, have a class discussion about how the pH of these products will affect the hair. 35

Acid-Alkali Neutralization Reactions Ionized water Neutralizing shampoos and normalizing lotions ACID–ALKALI NEUTRALIZATION REACTIONS The same reaction that naturally ionizes water into hydrogen ions and hydroxide ions also runs in reverse. When acids and alkalis are mixed together in equal proportions, they neutralize each other to form water. Neutralizing shampoos and normalizing lotions used to neutralize hair relaxers work by creating an acid-alkali neutralization reaction. Liquid soaps are usually slightly acidic and can neutralize alkaline callous softener residues left on the skin after rinsing.  Whether you are studying the pH of products, redox reactions, suspensions, solutions, or emulsions, there is a lot to learn about how chemistry affects the products you use in the salon. Having a basic understanding of chemistry will help you use professional products effectively and safely in the salon. 36

Summary and Review The science that deals with the composition, structure, and properties of matter and how matter changes under different chemical conditions is called chemistry. Organic chemistry deals with all substances in which carbon is present, while inorganic chemistry deals with substances that do not contain carbon. SUMMARY AND REVIEW • The science that deals with the composition, structure, and properties of matter and how matter changes under different chemical conditions is called chemistry. • Organic chemistry deals with all substances in which carbon is present, while inorganic chemistry deals with substances that do not contain carbon. (continues)

Summary and Review (continued) Matter is anything that occupies space, has physical and chemical properties, and exists as a solid, a liquid, or a gas. Matter exists in the form of elements, compounds, and mixtures. Matter can be changed either physically or chemically. There are many benefits for the client who takes advantage of the various salon services that use chemical products. While the use of chemical products has great benefits, we must always remember they create a potential for damage or injury as well. SUMMARY AND REVIEW (continued) • Matter is anything that occupies space, has physical and chemical properties, and exists as a solid, a liquid, or a gas. Matter exists in the form of elements, compounds, and mixtures. Matter can be changed either physically or chemically. • There are many benefits for the client who takes advantage of the various salon services that use chemical products. While the use of chemical products has great benefits, we must always remember they create a potential for damage or injury as well. (continues)

Summary and Review (continued) As a professional cosmetologist, your ability to stay informed about new developments and products and how to use them effectively and safely will greatly impact your success. SUMMARY AND REVIEW (continued) • As a professional cosmetologist, your ability to stay informed about new developments and products and how to use them effectively and safely will greatly impact your success.

Chapter Review Questions What is chemistry? Why is a basic understanding of chemistry important to a cosmetologist? What is the difference between organic and inorganic chemistry? CHAPTER REVIEW QUESTIONS 1. What is chemistry? Answer: Chemistry is the science that deals with the composition, structure, and properties of matter and how matter changes under different conditions. 2. Why is a basic understanding of chemistry important to a cosmetologist? Answer: To use professional products effectively and safely, all cosmetology professionals must have a basic understanding of chemistry. It is important to understand chemistry because hair color products, chemical texturizers, shampoos, conditioners, styling aids, nail enhancements, nail tips, and nail polishes have chemical substances.   3. What is the difference between organic and inorganic chemistry? Answer: Organic chemistry is the study of substances that contain the element carbon. Inorganic chemistry is the study of substances that do not contain carbon but may contain hydrogen. (continues) 40

Chapter Review Questions (continued) What is matter? What is an element? What are atoms? Explain the difference between elemental molecules and compound molecules. Give examples. CHAPTER REVIEW QUESTIONS (continued) 4. What is matter? Answer: Matter is any substance that occupies space and has mass (weight). 5. What is an element? Answer: An element is the simplest form of chemical matter. It cannot be broken down into a simpler substance without a loss of its identity. 6. What are atoms? Answer: Atoms are the smallest particle of an element that can exist either alone or in combination. All matter is made entirely of chemicals. They are the structural units that make up elements. 7. Explain the difference between elemental molecules and compound molecules. Give examples. Answer: Elemental molecules are molecules containing two atoms of the same element in definite proportions. An example is the atmospheric air that we breathe. Compound molecules are chemical combinations of two or more atoms of different elements in definite proportions. An example is table salt. (continues) 41

Chapter Review Questions (continued) 8. Name and describe the three states of matter. 9. What are the physical and chemical properties of matter? Give examples. 10. What is the difference between physical and chemical change? Give examples. CHAPTER REVIEW QUESTIONS (continued) 8. Name and describe the three states of matter. Answer: The three states of matter are: Solids: They are rigid and have a fixed shape and volume. Liquids: They have a definite volume but take the shape of their containers. Gases: They do not have a fixed volume or shape; they take the shape and volume of their containers. 9. What are the physical and chemical properties of matter? Give examples. Answer: Physical properties of matter are characteristics that can be determined without a chemical reaction and do not involve a chemical change. Examples of physical properties are color, size, weight, hardness, and glossiness. Chemical properties of matter are characteristics that can only be determined by a chemical reaction and a chemical change in the substance. Examples of chemical properties are rusting iron, burning wood, or hardening of nail enhancements. 10. What is the difference between physical and chemical change? Give examples. Answer: Physical change is a change in the form or physical properties of a substance without a chemical reaction or the creation of a new substance. Examples of physical change are when ice melts into water and then into a vapor, when a temporary hair color is applied to the hair, or when nail polish is taken off the nail with a remover solvent. Chemical change is a change in the chemical composition or make-up of a substance. Examples of chemical change are the oxidation of hair color or bleaching of melanin by peroxide. (continues) 42

Chapter Review Questions (continued) Explain oxidation-reduction (redox). Explain pure substances and physical mixtures. Give examples. What are the differences among solutions, suspensions, and emulsions? Give examples. Define pH and the pH scale. CHAPTER REVIEW QUESTIONS (continued) 11. Explain oxidation–reduction (redox). Answer: Oxidation–reduction is a chemical reaction in which the oxidizing agent is reduced and the reducing agent is oxidized. Chemical services would not be possible without oxidation–reduction (redox) reactions.  12. Explain pure substances and physical mixtures. Give examples. Answer: Pure substances are chemical combinations of matter in definite (fixed) proportions. Distilled Water is an example of a pure substance. Physical mixtures are physical combinations of matter in any proportions. A hair styling spray is an example of physical mixture. 13. What is the difference between solutions, suspensions, and emulsions? Give examples. Answer: A solution is a stable physical mixture of two or more substances. An example of a solution is salt water. A suspension is an unstable physical mixture of undissolved particles floating in a liquid. An example of a suspension is oil and vinegar salad dressing, in which the oil droplets are suspended in the vinegar. An emulsion is an unstable mixture of two or more substances that normally will not stay blended without a special ingredient called an emulsifier. An example of an emulsion is hand lotion. 14. Define pH and the pH scale. Answer: pH is the abbreviation used for potential hydrogen. The pH scale measures the acidity and alkalinity of a substance. It has a range of 0 to 14, with 7 being neutral. A pH below 7 is an acidic solution and a pH above 7 is an alkaline solution. 43