2 Using Vocabulary1. Adding a(n) inhibitor will slow down a chemical reactions.2. A chemical reaction that gives off light is called exothermic.
3 3. A chemical reaction that forms one compound from two or more substances is called a synthesis reaction.
4 4. The 2 in the formula Ag2S is a subscript. 5. The staring materials in a chemical reaction are reactants.
5 Understanding Concepts 6. Balancing a chemical equation so that the same number of atoms of each element is found in both the reactants and the products is an illustration ofC) the law of conservations of mass.
6 7. What is the correct chemical formula for calcium chloride? B) CaCl2Ca has a valence of 2, so 2+ chargeCl has a valence of 7, so -1 chargeSo 2 Cl- with Ca++ makes CaCl2
7 8. In which type of reaction do ions in two compounds switch places? D) double-replacementEx: NaOH + HCl --> NaCl + H2O
8 9. Which is an example of the use of activation energy? C) holding a match to paper
9 10. Enzymes in your body act as catalysts. The role of enzymes is to A) Increase the rate of chemical reactions (make the reactions happen faster)
10 Short Answers 11. Classify each of the following reactions: A) Fe + O2 --> Fe2O3 synthesisBalanced this would be4Fe + 3O2 --> 2Fe2O3Iron + oxygen --> rust
11 B) Al + CuSO4 --> Al2(SO4)3 + Cu single replacementBalanced this is2Al + 3CuSO4 --> Al2(SO4)3 + 3CuAluminum + cupric sulfide --> aluminum sulfide plus copper
12 C) Ba(CN)2 + H2SO4 --> BaSO4 +HCN Double replacementBalanced this isBa(CN)2 + H2SO4 --> BaSO4 + 2HCN
13 12. Name two ways that you could increase the rate of a chemical reaction. 1) raise the temperature( this increases the concentration and/or the surface area)2) add a catalyst
14 13. The reactants are acetic acid (vinegar) and baking soda (sodium bicarbonate). The products are carbon dioxide CO2 , water H2O, and sodium acetate.
15 14. Concept map is on the white board. Terms are:Chemical reactionChemical equationChemical formulasReactants, products,Coefficients, subscripts
16 Critical Thinking & Problem Solving 15. Your friend is very worried by rumors he has heard about a substance called dihydrogen monoxide. What could you say to your friend to calm his fears?Dihydrogen H2Monoxide OSo H2O - not to worry - its water !
17 16. As long as proper safety precautions have been taken, why can explosives be transported long distances without exploding?Explosives need to absorb energy to being the reaction. Without this absorption, they can be transported safely.
18 Math in Science17. Calculate the number of atoms of each element shown in each of the following:A) CaSO4Ca - Calcium - 1 atomS - Sulfur - 1 atomO - Oxygen - 4 atoms
28 19) Balanced chemical equations: A) bromine reacts with sodium iodide to form iodine and sodium bromideBr2 + 2NaI --> I NaBr
29 B) Phosphorus reacts with oxygen gas to form diphosphorus pentoxide 4P + 5O2 --> 2P2O5
30 C) Lithium oxide decomposes to form lithium and oxygen 2Li2O --> 4Li + O2
31 Interpreting Graphics 20. In the photo on page 393, what evidence supports that this is a chemical reaction?Answer- Bubbles of gas are produced- Light is given off
32 21. Using the energy diagram on page 393, answer q’s a,b,c A) “C” represents the energy of the products (far right section of graph)B) “B” represents the activation energy of the reaction (increases then peaks)C) Energy is “given off” by this reaction.That’s the decline of energy below starting energy mark - “D” on the chart)