1. Slide 1 of 37 chemistry

2. © Copyright Pearson Prentice Hall Slide 2 of 37 Describing Chemical Reactions On May 6, 1937, the huge airship Hindenburg erupted into a fireball. Within a short time, 210,000 cubic meters of hydrogen had burned and the airship was destroyed. The chemical reaction that occurred is “hydrogen combines with oxygen to produce water.” You will learn to represent this chemical reaction by a chemical equation. 11.1

3. © Copyright Pearson Prentice Hall Describing Chemical Reactions > Slide 3 of 37 Writing Chemical Equations How do you write a word equation? 11.1

4. Slide 4 of 37 © Copyright Pearson Prentice Hall Describing Chemical Reactions > Writing Chemical Equations Word Equations To write a word equation, write the names of the reactants to the left of the arrow separated by plus signs; write the names of the products to the right of the arrow, also separated by plus signs. Reactant + Reactant  Product + Product 11.1

5. Slide 5 of 37 © Copyright Pearson Prentice Hall Describing Chemical Reactions > Writing Chemical Equations Methane + Oxygen  Carbon dioxide + Water 11.1

6. Slide 6 of 37 © Copyright Pearson Prentice Hall Describing Chemical Reactions > Writing Chemical Equations iron + oxygen  iron(III) oxide 11.1

7. Slide 7 of 37 © Copyright Pearson Prentice Hall Describing Chemical Reactions > Writing Chemical Equations Hydrogen Peroxide  Water and Oxygen 11.1

8. Slide 8 of 37 © Copyright Pearson Prentice Hall Describing Chemical Reactions > Writing Chemical Equations Chemical Equations A chemical equation is a representation of a chemical reaction; the formulas of the reactants (on the left) are connected by an arrow with the formulas of the products (on the right). 11.1

9. © Copyright Pearson Prentice Hall Describing Chemical Reactions > Slide 9 of 37 Writing Chemical Equations How do you write a skeleton equation? 11.1

10. Slide 10 of 37 © Copyright Pearson Prentice Hall Describing Chemical Reactions > Writing Chemical Equations A skeleton equation is a chemical equation that does not indicate the relative amounts of the reactants and products. Here is the equation for rusting: Fe + O 2  Fe 2 O 3 11.1

11. Slide 11 of 37 © Copyright Pearson Prentice Hall Describing Chemical Reactions > Writing Chemical Equations Write the formulas of the reactants to the left of the yields sign (arrow) and the formulas of the products to the right. 11.1

12. Slide 12 of 37 © Copyright Pearson Prentice Hall Describing Chemical Reactions > Writing Chemical Equations A catalyst is a substance that speeds up the reaction but is not used up in the reaction. Without Catalyst With Catalyst 11.1

13. Slide 13 of 37 © Copyright Pearson Prentice Hall Describing Chemical Reactions > Writing Chemical Equations 11.1

14. © Copyright Pearson Prentice Hall Slide 14 of 37 Describing Chemical Reactions > Writing Chemical Equations Animation 12 Relate chemical symbols and formulas to the information they communicate.

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18. © Copyright Pearson Prentice Hall Slide 18 of 37 Practice Problems for Conceptual Problem 11.1 Problem Solving 11.2 Solve Problem 2 with the help of an interactive guided tutorial.

19. © Copyright Pearson Prentice Hall Describing Chemical Reactions > Slide 19 of 37 Balancing Chemical Equations What are the steps in writing a balanced chemical equation? 11.1

20. © Copyright Pearson Prentice Hall Slide 20 of 37 Describing Chemical Reactions > Balancing Chemical Equations To write a balanced chemical equation, first write the skeleton equation. Then use coefficients to balance the equation so that it obeys the law of conservation of mass. 11.1

21. Slide 21 of 37 © Copyright Pearson Prentice Hall Describing Chemical Reactions > Balancing Chemical Equations This is a balanced equation for making a bicycle. The numbers are called coefficients—small whole numbers that are placed in front of the formulas in an equation in order to balance it. 11.1

22. Slide 22 of 37 © Copyright Pearson Prentice Hall Describing Chemical Reactions > Balancing Chemical Equations A chemical reaction is also described by a balanced equation in which each side of the equation has the same number of atoms of each element and mass is conserved. 11.1

23. © Copyright Pearson Prentice Hall Slide 23 of 37 Describing Chemical Reactions > Balancing Chemical Equations Simulation 11 Sharpen your skills by balancing chemical equations.

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28. © Copyright Pearson Prentice Hall Slide 28 of 37 Practice Problems for Conceptual Problem 11.2 Problem Solving 11.4 Solve Problem 4 with the help of an interactive guided tutorial.

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33. © Copyright Pearson Prentice Hall Slide 33 of 37 11.1 Section Quiz. 1.Propane gas reacts with oxygen to produce water vapor and carbon dioxide. Choose the correct word equation for this reaction. a.propane + carbon dioxide  water + oxygen b.propane + oxygen + water  carbon dioxide c.propane + oxygen + water + carbon dioxide d.propane + oxygen  water + carbon dioxide

34. © Copyright Pearson Prentice Hall Slide 34 of 37 2.Which of the following is a skeleton equation? a.H 2 + CO  CH 3 OH b.2H 2 + CO  CH 3 OH c.2H 2 + CO 2  CH 3 OH d.hydrogen + carbon monoxide  methanol 11.1 Section Quiz.

35. © Copyright Pearson Prentice Hall Slide 35 of 37 3.What coefficient for H 2 SO 4 is required to balance the following equation? Ca 3 (PO 4 ) 2 + ____ H 2 SO 4  3CaSO 4 + 2H 3 PO 4 a.1 b.2 c.3 d.4 11.1 Section Quiz.

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