2“The greater the difficulty, the more glory in surmounting it “The greater the difficulty, the more glory in surmounting it. Skillful pilots gain their reputation from storms and tempests”Epictetus
3ObjectivesExplain the difference between organic and inorganic chemistryDiscuss the different forms of matter: elements, compounds, and mixturesExplain pH and the pH scaleDescribe oxidation and reduction (redox) reactionsLEARNING MOTIVATION (WHY?)As a professional in the field of cosmetology, it is essential that you understand the chemicals you will be using in the services you perform. Many of the services you will provide change the hair, skin, and nails chemically as well as physically. Throughout the course of study, we stress the importance of safety in the workplace. The knowledge you will gain in this unit of study will be invaluable to your own safety and that of your client.When you think about it, chemistry has an important role in every product you use, from the water used to shampoo hair, to the cosmetics applied during a facial, to the chemicals used to chemically reform the hair’s texture, to the products used to care for the hands, feet, and nails.Chemistry may be a frightening subject to you, but there is no need for that, especially when you think about what chemistry is. It is simply the study of matter, its composition, structure, and properties, and the changes they may undergo under different chemical conditions. Because matter is anything that occupies space and has weight, it is significant to our profession.Organic chemistry deals with all substances in which carbon is present. The term organic in chemistry refers to something that is living or has ever been alive. The term organic is often misused to mean “natural.” Organic chemistry includes animals, plants, petroleum, soft coal, natural gas, and many artificially prepared substances. Most will burn, but cannot be liquefied, even though they will dissolve in organic solvents such as alcohol and benzene.Inorganic chemistry is the branch that deals with all substances or compounds that do not contain carbon such as water, air, metals, and minerals. Inorganic substances are not and never were alive. These substances will not burn and are usually soluble in water. Remember, our intention in this unit is not to make you a scientist, but to help you develop a comfort level with the basics and your ability to discuss chemistry in relation to your profession. This ability will make a significant contribution to your many client consultations.
4MatterAnything that occupies space, has physical and chemical properties, and exists as a solid, liquid, or gasOPENING ACTIVITY: 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 either 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 2 hours or so of being awake today nearly every aspect of their lives was affected by chemistry.MATTER: Anything that occupies space, has physical and chemical properties, and exists as a solid, liquid, or gas.
5Elements Simplest form of matter Cannot be reduced without loss of identity90 – natural22 – artificialIdentified by a letter symbolC – O – H – N – SELEMENTSComposed of a single part or unit; the simplest form of matter.Cannot be reduced to a simpler substance, at least not without loss of identity.Ninety naturally occurring elements. There are 22 more elements that are made artificially. All matter in the universe is made up of one or more of these 90 elements.Identified by the acronym COHNS:C: CarbonO: OxygenH: HydrogenN: NitrogenS: Sulfur
6Atoms and Molecules Atom: Particles from which all matter is composed. Molecules: Result ofjoined atoms.Elemental moleculeCompound moleculeATOMS: The particles from which all matter is composed. Smallest particle of an element capable of showing the properties of that element. Example: If you took a piece of gold (an element) and divided it into smaller and smaller pieces, you would eventually come to a particle so small that it no longer showed the properties of the element (it would no longer be recognizable as gold).MOLECULES: Result of two or more atoms being joined together.Elemental molecules. Contain two or more atoms of the same element that are united chemically. The oxygen we breathe is an elemental molecule O2. The ozone in the atmosphere is an elemental molecule O3.Compound molecule. Chemical compounds of two or more atoms of different elements. Sodium chloride (NaCl), or common table salt, is a compound molecule that contains one atom of sodium (Na) and one atom of chlorine (Cl).
7States of Matter Solid: Have shape, volume, weight (ice) Liquid: Have volume and weight, no shape (water)Gas: Have no volume or shape (steam)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 (e.g., ice).Liquid. Have a definite volume and weight, but not a definite shape (e.g., water, which takes on the shape of its container).Gases. Do not have a definite volume or shape (e.g., steam).
8Physical and Chemical Properties Physical: Determinedwithout a chemicalreaction (color, odor,weight, density)PHYSICAL AND CHEMICAL PROPERTIESPhysical. Those characteristics determined without a chemical reaction; do not cause a chemical change in the identity of a substance. Examples: color, odor, weight, density.Chemical. Those characteristics that can only be determined with a chemical reaction and cause a chemical change in the identity of a substance. Examples: rusting iron, burning wood. A chemical reaction known as oxidation causes the chemical change in the identity.
9Physical and Chemical Properties Chemical: Determined with a chemical reaction (change identity – rusting iron, burning wood)
10Pure Substances and Mixtures Pure substances (distinct properties)Mixtures (elements combined physically)PURE SUBSTANCES: Matter with a fixed chemical composition and distinct properties.PHYSICAL MIXTURES: A substance made up of elements combined physically rather than chemically. Ingredients do not change their properties. For example, concrete is a mixture of sand, gravel, and cement; the sand and gravel are held together by the cement, but they retain their identity and can be picked apart. Air is a mixture of gases, mostly nitrogen and oxygen.
11Solutions, Suspensions, Emulsions SoluteSolventMiscible liquidsImmiscible liquidsSuspensionEmulsionSOLUTIONS, SUSPENSIONS, AND EMULSIONS: All contain two or more different substances.Solution. A blended mixture of two or more liquids or a solid dissolved in a liquid. They don’t separate on standing.Solute. The dissolved substance in a solution.Solvent. The substance, usually liquid, that dissolves another substance to form a solution, with no change in chemical composition. For example, when sugar is dissolved in hot water, sugar (a solid) is the solute and the water (liquid) is the solvent.Miscible liquids. Are mutually soluble; can be mixed with each other in any proportion without separating (e.g., water and alcohol).Immiscible liquids. Not capable of being mixed (e.g., oil and water).Suspension. A state in which solid particles are distributed throughout a liquid medium. They have a tendency to separate over time (e.g., salad dressings, which often have to be shaken well before using to mix thoroughly).Emulsion. A mixture of two or more immiscible substances united with the aid of a binder or emulsifier. They have a tendency to separate over time, but if properly formulated can be stable for at least 1 or 2 years.
12Surfactants Head Tail Surfactant molecule Oil in water emulsion (O/W) SURFACTANTS: Substances that act as a bridge to allow oil and water to mix, or emulsify. The term is a contraction for “surface active agent.”Head of the surfactant. Is hydrophilic or water loving and dissolves in water.Tail of surfactant. Is lipophilic or oil loving and dissolves in oil.Surfactant molecule. Dissolves in both oil and water and joins them together to form an emulsion. It creates a “shell,” which walls off the oil from the water, allowing them to coexist.Oil in water emulsion. O/W— Oil droplets are suspended in a water base. Oil droplets are surrounded by surfactants; their lipophilic tails point in and their hydrophilic heads point out. Oil in water emulsions usually contain a much greater amount of water than oil. Mayonnaise is O/W. Oil and water are immiscible, but the egg yolk emulsifies the oil droplets and distributes them uniformly in the water. Most emulsions used in the salon are O/W. Haircoloring, shampoos, and conditioners are O/W.
13Surfactants Water in oil emulsion (W/O) Water in oil emulsion. W/O — Water droplets are suspended in an oil base. Droplets are surround by surfactants; their hydrophilic heads pointing in and their lipophilic heads pointing out. Water forms the internal portion of a W/O emulsion and there is a much greater amount of oil than water. Cold cream is an example of a W/O emulsion.
14Other Physical Properties OintmentsPowdersOTHER PHYSICAL MIXTURESOintments. Semisolid mixtures made with any combination of petrolatum (petroleum jelly), oil, and wax; include ointments, pastes, pomades, and styling waxes.Powders. Physical mixtures of two solids. Free-flowing powders are rarely found in cosmetics; powders that tend to stick together, such as talc, are more common.
15Common Ingredients Alcohol Alkanolamines Ammonia Glycerine COMMON PRODUCT INGREDIENTSAlcoholReadily evaporating.Colorless.Volatile alcohols. Evaporate easily — isopropyl (rubbing alcohol), ethyl (alcoholic beverages).Fatty alcohols. Cetyl and cetearyl alcohols are nonvolatile oils that are used as conditioners.Alkanolamines. Substances used to neutralize acids or raise the pH of many hair products. Often used in place of ammonia.• AmmoniaColorless with a pungent odor.Composed of nitrogen and hydrogen. In a water solution, it is called ammonia water.Used to raise pH in permanent waving, haircoloring, and lightening substances. Raising the pH (potential hydrogen) softens and swells the cuticle, allowing solution to penetrate the hair shaft.• GlycerineSweet, colorless, oily substance.Used as a solvent and moisturizer.
16Common Ingredients Silicones Volatile organic compounds Silicones. Used as hair conditioners and water-resistant lubricants for the skin. They are less greasy than many other oils and can impart a silky smooth feel on skin and give shine to hair.Volatile organic compounds. (VOCs). Two or more elements combined chemically (compounds) that contain carbon (organic) and evaporate quickly (volatile). The most common VOC used in hair sprays is ethyl alcohol.
17Potential Hydrogen and Ions IonizationAnionCationPOTENTIAL HYDROGEN AND IONSIon. An atom or molecule that carries an electrical charge.Ionization. The temporary separation of a substance into ions.Anion. An ion with a negative electrical charge.Cation. An ion with a positive electrical charge.
18Water and pH Hydrogen ion (H+) is acidic Hydrogen 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.• Hydrogen ion (H+) is acidic.• 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% acid and 50% alkaline.
19The pH Scale pH: Parts hydrogen or potential hydrogen The scale: 0 – 14pH 7: neutralTHE pH SCALE: It means either “parts hydrogen” or “potential hydrogen.” It means the relative degree of acidity or alkalinity of a substance. The symbol pH represents the number of hydrogen ions in a water solution.• A scale of 0 to 14• 7 indicates a neutral solution• Below 7 indicates an acidic solution• Above 7 indicates an alkaline solution
20Acids Acids pH below 7.0 Turn litmus paper from blue to red Contracts and harden hairACIDS: Owe their chemical relativity to the hydrogen ion (H+).• pH below 7.0.• Turn litmus paper from blue to red.• Contract and harden hair. Thioglycolate acid is used in permanent waving.
21Alkalis pH above 7.0 Known as “base” Turn litmus paper from red to blueFeel slippery and soapy on skinSoften and swell hairALKALIS: Owe their chemical relativity to the hydroxide ion (OH).Term is interchangeable with base.pH above 7.0.Turn litmus paper from red to blue.Feel slippery and soapy on the skin.Soften and swell hair. Sodium hydroxide, commonly known as lye, is a very strong alkali used in chemical drain cleaners and chemical hair relaxers.ACTIVITY: Have students conduct the activity found in the textbook wherein litmus paper is dipped into numerous products and the various pH levels are determined.
22Acid-Alkali Neutralization Reactions Pure waterNeutralizing shampoos and normalizing lotionsACID-ALKALI NEUTRALIZATION REACTIONS• Pure water. Naturally ionizes to create hydrogen (H+) ions and hydroxide ions (OH-). When acids (H+) and alkalis (OH-) are mixed together in equal proportions, they neutralize each other to form water (H2O).• Neutralizing shampoos and normalizing lotions. Neutralize hydroxide hair relaxers; when acidic or alkaline lotions are neutralized, heat is also generated.
23Oxidation Reactions Oxidation Oxidation-reduction Exothermic CombustionOXIDATION REACTIONSOxidation. Oxidation is a chemical reaction that combines an element or compound with oxygen to produce an oxide.Oxidation-reduction (redox) reactions. Responsible for the chemical changes created by haircolors, hair lighteners, permanent wave solutions, and neutralizers.Exothermic. Chemical reactions that are characterized by or formed with the giving off of heat.Combustion. The rapid oxidation of any substance accompanied by the production of heat and light. Lighting a match is an example of rapid oxidation. You cannot have a fire without oxygen.ACTIVITY: Have students complete the activity found in the textbook which demonstrates that oxidation reactions produce heat. Gather the supplies and materials before class.
24Reduction Reactions Oxidized Reduction Oxidizing agent Oxidized. When a substance is combined with oxygen, the substance is oxidized.Reduction. When oxygen is subtracted from a substance, the substance is reduced; the chemical reaction is called reduction.Oxidizing agent. The substance that releases oxygen. Hydrogen Peroxide (H2O2) is an example of an oxidizing agent.
25Redox Redox (a contraction from “reduction” and “oxidation”) Oxidation (relocating hydrogen)Reduction (adding or subtracting hydrogen)REDOX: A contraction for reduction-oxidation. In redox reactions, the oxidizing agent is reduced and the reducing agent is oxidized.Oxidation can also occur when hydrogen is removed from one substance and added to another.Reduction is the result of either the loss of oxygen or the addition of hydrogen.
26Summary and Review What is chemistry? 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. We know that organic chemistry deals with all substances in which carbon is present, while inorganic chemistry deals with substances that do not contain carbon. We know that matter is anything that occupies space, has physical and chemical properties, and exists as either a solid, a liquid, or a gas. Matter exists in the form of elements, compounds, and mixtures. Atoms are the smallest particle of an element (which shows the properties of that element) while a molecule is two or more atoms joined together chemically. We’ve learned that 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. As a professional in the image enhancement industry, your ability to stay informed about new developments and products and how to use them effectively and safely will greatly impact your success.Let’s review.What is chemistry?ANSWER: The science that deals with the composition, structures, and properties of matter, and how matter changes under different chemical conditions.
27Summary and ReviewWhy is a basic understanding of chemistry important?What is the difference between organic and inorganic chemistry?What are atoms?What are elements?What are the physical and chemical properties of matter?Why is a basic understanding of chemistry important?ANSWER: Permanent waving, chemical hair relaxing, and haircoloring all rely on the use of chemicals. To use them safely, you need to have a basic working knowledge of chemistry.What is the difference between organic and inorganic chemistry?ANSWER: Organic chemistry is the study of substances that contain carbon. Inorganic chemistry deals with compounds lacking carbon.What are atoms?ANSWER: The smallest particle of an element that still retains the properties of that element.What are elements?ANSWER: The simplest form of matter that cannot be broken down into a simpler substance without loss of identity.What are the physical and chemical properties of matter? Give examples.ANSWER: Physical properties are those characteristics that can be determined without a chemical reaction and that do not cause a chemical change in the identity of the substance (e.g., color, odor, weight, density, specific gravity, melting point, boiling point, hardness). Chemical properties are those characteristics that can only be determined with a chemical reaction and that cause a chemical change in the identity of the substance (e.g., rusting iron, burning wood).
28Summary and ReviewWhat is the difference between physical and chemical changes. Give examplesDescribe 3 states of matter. Explain elements, compounds, and mixturesWhat is the difference between physical and chemical changes. Give examples.ANSWER: Physical change is a change in the form of physical properties of substance without the formation of a new substance (e.g., ice melts to water; temporary haircolor). Chemical change is a change in the chemical composition of a substance in which a new substance or substances are formed having properties different from the original (e.g., iron into rust; wood into charcoal; permanent haircolor).Describe the three states of matter.ANSWER: Solids have a definite shape, volume, and weight. Liquids have a definite volume and weight but not a definite shape. Gases do not have a definite volume or shape.Explain elements, compounds, and mixtures.ANSWER: An element is the simplest form of matter and cannot be broken down into a simpler substance without loss of identity. Compounds are chemical combinations of two or more atoms of different elements. Mixtures are substances made up of elements combined physically rather than chemically.
29Summary and ReviewWhat is the difference between solutions, suspension, and emulsions? Give examplesDefine pH and the pH scaleExplain the difference between oxidation and reduction reactionsWhat is the difference between solutions, suspensions, and emulsions? Give examples.ANSWER: A solution is a blended mixture of two or more solids, liquids, or gaseous substances. (e.g., salt water, water, air, and hydrogen peroxide). A suspension is a state in which solid particles are distributed throughout a liquid medium (e.g., vinegar and oil). An emulsion is a mixture of two or more immiscible substances united with the aid of a binder or emulsifier.Define pH and the pH scale.ANSWER: pH refers to the relative degree of acidity and alkalinity of a substance. The pH values range from 0 to 14. A pH of 7 indicates a neutral solution, a pH below 7 indicates an acidic solution, and a pH above 7 indicates an alkaline solution.Explain the difference between oxidation and reduction reactions.ANSWER: Oxidation is a chemical reaction that combines an element or compound with oxygen to produce an oxide. When oxygen is subtracted from a substance, the substance is reduced and the chemical reaction is called reduction.
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