How do Chemical Reactions Affect Our Daily Lives?.

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    04-Jan-2016

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How do Chemical Reactions affect your daily life?How do Chemical Reactions Affect Our Daily Lives?Practical ApplicationsHave a use that people consider important, handy or helpfulGroup ActivityGroups of 3 Writer, task manager, time watcherCome up with a definition of chemical reactionDiscuss photos on page 110 and 111. Explain why each involves a chemical reactionList 3 more chemical reactions you consider to have practical applicationsList 3 chemical reactions you consider NOT to have practical applicationsChemical Reactions with practical applicationsChemical reactions that have a use that people consider important, handy or helpfule.g. Burning wood is useful for creating heat for a homee.g. the millions of chemical reactions occurring in our bodies that take food and turn it into energy that helps run our bodies and helps us grow.Chemical Reactions that are NOT practicalChemical reactions that are not helpful or handy and may even be a nuisance.e.g. rusting, corrosion, rotting, condensation build upSummarizing Group activityCar Battery: chemicals react to produce electricity to run a vehicleWelder: chemical reaction which allows one to mend together two pieces of metal, creating a strong bond between both piecesFlare: a chemical reaction that burns for a long period of time, allowing one to use the light and smoke to signal for helpFood preservatives: chemical reaction with the food which helps keep food fresh for longer periods of timeSummarizing Group activity contSummarizing Group activity contFresh-baked bread: chemicals (yeast) in the bread dough react to create a nice fluffy, tasty loaf instead of a flat hard chewy one.Food cooking: the fuel burned allows one to cook food to make it tasty.Summarizing Group activity contEthanol added to gasoline: creates a fuel that allows a vehicle to burn cleaner and put lest pollutants in the air.Bleach: useful in disinfecting things and brightening fabricsChemical Reactions in Our LivesChemical Reaction: A change in matter that produces one or more new substances with new propertiesPhysical and Chemical Propertiesphysical property: a description of how a substance looks. No new substance is formed. Requires you to use your five senses to observe.e.g. colour, texture, density, odor, solubility, taste, hardness, magnetism, luster, malleability.chemical property: a description of the changes a substance can undergo to form one or more new substance(s)e.g. Reaction with an acid or base, flammability, bleaching ability, corrosion, rust, production of a gas, reactivity.https://www.youtube.com/watch?v=oF0lN0jZYx0Physical and Chemical Changesphysical changes: does not produce a new substance and can sometimes be easily reversed.e.g. changes of state (melting, evaporating, condensation, sublimation and dissolving).Dissolving sugar in water can be reversed by evaporating the water offCutting a log in half cannot be reversedPhysical and Chemical Changes Continuedchemical change: change a substance undergoes which produces one or more new substances. Is usually difficult to reverse.e.g. new colour appears, a solid or precipitate appears, heat/light is absorbed or produced, bubbles are formed, forest fires, rusting of a vehicle, rotting of banana are impossible to reverseA rechargeable battery can be reversedPhysical or Chemical ChangeThat is the Question!a. perfume evaporating on your skin b. butter melting c. wood rotting d. autumn leaves changing color e. burning sugar f. mixing sugar in water g. digesting foodh. freezing water to make ice cubes i. burning gasoline in a lawnmower j. tearing a piece of aluminum foilk. grating cheese l. fermenting of cheese a. boil b. burn (combustion) c. condense d. corrode e. crumple f. ferment g. melt h. rust i. crush j. freeze k. oxidize l. tarnish m. explode n. grind o. rot p. vaporize q. photosynthesis r. sublimation Physical or Chemical ChangeThat is the Question!What Makes up a Chemical Reaction?Reactants: substances that react together in a chemical reactionProducts: new substances produced in a chemical reactionReactants ProductsImportant Reactions

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