Chemical Reactions. 1. What is the difference between a physical change and a chemical change

Transcription

1 What is a Chemical Reaction Chemical Reactions 1. What is the difference between a physical change and a chemical change 2. Give an example of a physical change and a chemical change using paper. 3. What is a chemical reaction? 4. How are new chemicals made? Evidence of Chemical Reactions 5. How do we know if a chemical reaction has occurred? 6. If evidence of a chemical reaction is present, is that a guarantee that a chemical reaction occurred? Explain 7. Does all the evidence for a chemical reaction have to be present for a chemical reaction to have occurred? Explain

2 Rate of Chemical Reactions 8. How is the chemical rate of a reaction changed? 9. What are the seven factors that affect the rate of chemical reactions?

3 Types of Chemical Reactions 10. What are the four main kinds of chemical reactions? 11. Identify the following reactions as synthesis, decomposition, replacement, or combustion a. A + B C b. A + BC AB + C c. 2Ag + S Ag 2 S d. C 6 + O 12 6CO 2 e. Cl 2 + 2NaBr Br 2 + 2NaCl f. CH 4 + 2O 2 CO 2 + 2H 2 O

4 Chemical Equations 12. What is a chemical equation? 13. What are the reactants and where are they found in a chemical equation? 14. What are the products and where are they found in a chemical equation? 15. Why do chemical equations have to be balanced? 16. Complete the following table Reaction Reactant Product Other Photosynthesis Cellular Respiration 17. Identify the reactants and the products in the following reactions a. Hydrogen gas + Oxygen gas makes water b. Sugar ferments to ethyl alcohol and carbon dioxide c. Alcohol + oxygen becomes vinegar and water d. Burning methane releases carbon dioxide & water

5 Energy and Chemical Reactions 18. What does the term thermic refer to? 19. What does the prefix endo- refer to? 20. What does the prefix exo- refer to? 21. Are the following reactions exothermic or endothermic a. A + B + Energy AB b. AB A + B + Energy c. H 2 O + Energy 2H 2 + O 2 d. 2H 2 + O2 H 2 O + Energy 22. Complete the Venn Diagram for Endo and Exo thermic Reactions Endothermic Exothermic Energy

6 ph 23. Why do we write ph the way we do? 24. Define ph 25. What is an acid 26. What is a base 27. What is a mole? 28. What is the ph of water? 29. Explain why water can act as both an acid and a base 30. What are the three ways we measure the ph of solutions? 31. What are five examples of acids and five examples of bases 32. What is the impact to wildlife if the ph of an ecosystem is altered? Give specific examples.

7 Chemical Reaction Lab Results Rate of Chemical Reactions 1. Predict how changing the reactants will change the rate of the reaction? 2. Predict how changing the temperature will change the rate of the reaction? 3. Predict how stirring the mixture will change the rate of the reaction? 4. Predict how increasing the surface area will change the reaction? 5. How did changing the reactants change the rate of the reaction? 6. How did changing the temperature change the rate of the reaction? 7. How did stirring the mixture change the rate of the reaction? 8. How did increasing the surface area change the reaction? Energy and Chemical Reactions 9. What happened to the temperature of the hydrogen peroxide/yeast mixture? 10. What happened to the temperature of the baking soda/vinegar mixture? What is a Mole 11. Mass of chalk before writing your name: 12. Mass of chalk after writing your name: 13. Grams of chalk required to write your name: 14. Moles of CaCO 3 required to write your name:

8 The ph of Beans 15. How many times more acidic is a ph of 6 than a ph of 7? 16. How many times more acidic is a ph of 6 than a ph of 8? 17. Using this scenario, how many beans would be in a solution with a ph of 3? 18. Using this scenario, how many beans would be a in a solution with a ph of 9. Be careful, this is a trick question In order to make a solution with a ph of 9, what would you have to do Cabbage Acid and Base 20. Predict and then identify the following as an acid or a base or neutral a. Tap Water b. Soda Water c. Vinegar d. Milk e. Cranberry Juice f. Apple Juice g. Tums h. Baking Soda i. Bleach Measuring ph 21. Predict and then measure the ph of the following substances a. Tap Water b. Soda Water c. Vinegar d. Milk e. Cranberry Juice f. Apple Juice g. Tums h. Baking Soda i. Bleach