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Understanding Chemical Resources: Impacts and Applications

Explore the fundamentals of chemical resources, reactions, and conservation, highlighting properties, corrosion, balancing equations, and economic impacts in applied chemistry. Dive into key topics such as waste, recycling, hazardous household products, and the law of conservation of mass.

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Understanding Chemical Resources: Impacts and Applications

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  1. Chemical Resources and Reactions Applied Chemistry Milbank High School

  2. Chemical Resources What is a chemical resource? • Natural Resource • Renewable Resource • What are some renewable resources?

  3. Chemical Resources • Nonrenewable Resource • What are some nonrenewable resources? • Waste • What are common waste products? • Recycling • How do we recycle?

  4. Household Hazardous Wastes • Cleaning Products • Indoor pesticides • Automotive Products • Painting Supplies • Lawn Products • Misc.

  5. Household Hazardous Wastes • Americans generate 1.6 million tons of HHW per year. • The average home can accumulate as much as 100 pounds of HHW in the basement and garage and in storage closets.

  6. Properties • Words that describe matter (adjectives) • Physical Properties- a property that can be observed and measured without changing the composition. • Examples- color, hardness, m.p., b.p. • Chemical Properties- a property that can only be observed by changing the composition of the material.

  7. Changes • Physical changes- A change that changes appearances, without changing the composition. • Ex. Boil, melt, cut, bend, split, crack • Boiled water is still water. • Chemical changes - a change where a new form of matter is formed. • Ex. Rust, burn, decompose, ferment

  8. Corrosion/Rust • Corrosion • Deterioration of the properties of a material due to reactions with the environment • Reaction with water or air • Rust • Corrosives • Solid, liquid, or gas capable of harming living tissues or damaging material on contact • Not repairable • Acids • Bases

  9. Other Types of Corrosion • Microbial Corrosion • Bacteria • High-temperature corrosion • Aerospace • Power generation

  10. Surface Treatments • Applied coatings • Plating, painting, enamels • Reactive coatings • Corrosion inhibitors • Salts

  11. Economic Impact • A study showed that for 1998 the total annual estimated direct cost of corrosion in the U.S. was approximately $276 billion (approximately 3.1% of the US gross domestic product) • Structures, machines, and containers

  12. Law of Conservation of Mass • Mass can not be created or destroyed in ordinary (not nuclear) chemical reactions or physical change • All the mass can be accounted for. • Burning of wood results in products that appear to have less mass as ash; where is the rest?

  13. All chemical reactions • Have two parts: • Reactants - the substances you start with • Products- the substances you end up with • The reactants turn into the products. • Reactants ® Products

  14. In a chemical reaction • The way atoms are joined is changed • Atoms aren’t created of destroyed. • Can be described several ways: 1. In a sentence Copper reacts with chlorine to form copper (II) chloride. 2. In a word equation Copper + chlorine ® copper (II) chloride

  15. Symbols in equations • the arrow separates the reactants from the products • Read “reacts to form” • The plus sign = “and” • (s) after the formula = solid • (g) after the formula = gas • (l) after the formula = liquid

  16. What is a catalyst? • A substance that speeds up a reaction, without being changed or used up by the reaction. • Enzymes are biological or protein catalysts.

  17. Indications of a chemical reaction: • Energy absorbed or released (temperature changes hotter or colder) • Color change • Gas production (bubbling, fizzing, or odor change) • formation of aprecipitate- a solid that separates from solution (won’t dissolve) • Irreversibility- not easily reversed

  18. Balancing Chemical Equations

  19. Balanced Equation • Atoms can’t be created or destroyed • All the atoms we start with we must end up with • A balanced equation has the same number of each element on both sides of the equation.

  20. ® O + C C O O O • C + O2® CO2 • This equation is already balanced • What if it isn’t?

  21. ® O + C C O O • C + O2® CO • We need one more oxygen in the products. • Can’t change the formula, because it describes what it is (carbon monoxide in this example)

  22. C O ® O + C O • Must be used to make another CO • But where did the other C come from? C O

  23. C C O ® O + O • Must have started with two C • 2 C + O2® 2 CO C O C

  24. Rules for balancing: • Assemble, write the correct formulas for all the reactants and products • Count the number of atoms of each type appearing on both sides • Balance the elements one at a time by adding coefficients (the numbers in front) - save H and O until LAST! • Check to make sure it is balanced.

  25. Never • Never change a subscript to balance an equation. • If you change the formula you are describing a different reaction. • H2O is a different compound than H2O2 • Never put a coefficient in the middle of a formula • 2 NaCl is okay, Na2Cl is not.

  26. Balancing Examples • _AgNO3 + _Cu ® _Cu(NO3)2 + _Ag • _Mg + _N2® _Mg3N2 • _P + _O2® _P4O10 • _Na + _H2O ® _H2 + _NaOH • _CH4 + _O2® _CO2 + _H2O

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