Indicate the answer choice that best completes the statement or answers the question.

Transcription

1 Indicate the answer choice that best completes the statement or answers the question. 1. Which of the following bonds is polar? a. F F b. O H c. O O d. H H 2. In the compound, H 2 O, the electrons in the bonds are unequally shared between oxygen and hydrogen, forming. a. cations b. ionic bonds c. nonpolar molecules d. polar bonds 3. Which statement proves that a chemical reaction has occurred? a. Bubbles form in a liquid. b. At least one substance changes color. c. Substances with new chemical properties are formed. 4. Zinc combines with hydrochloric acid, the zinc replaces hydrogen. The chemical equation for this reaction looks like: Zn + 2HCl ZnCl 2 + H 2 This is a reaction a. synthesis b. decomposition c. single-replacement d. double-replacement 5. Which activity is a type of combustion reaction? a. burning wood b. breaking down water c. formation of table salt 6. In a chemical reaction, energy is released. a. only when bonds are broken b. only when bonds are formed c. when bonds break and when bonds form 7. In the chemical formula H 2 O, how many atoms of oxygen are represented? a. one b. two c. three 8. A change in is a sign of energy being used in a chemical reaction. a. temperature b. color c. odor d. texture Powered by Cognero Page 1

2 9. Ethanol has six hydrogen atoms, two carbon atoms, and one oxygen atom. Which is the correct chemical formula of the model below? a. C 2 H 6 O b. 2CH 6 O c. 6HCO d. C 2 6HO 10. Which of the following elements will likely form a negative ion in its ionic compounds? a. Li, lithium b. Al, aluminum c. Mg, magnesium d. Cl, chlorine 11. Metallic compounds. a. are poor conductors of electricity b. dissolve in water c. have low melting points d. can be hammered into sheets 12. Which pair of reactions are considered to be opposites? a. synthesis and decomposition b. single-replacement and synthesis c. decomposition and double-replacement d. single-replacement and double-replacement 13. If the arrangement of atoms in a substance changes, then which of the following is true? a. A chemical reaction has occurred. b. The physical state of the substance changes. c. The chemical properties of the substance stay the same but the physical properties change. d. The physical properties of the substance stay the same but the chemical properties change. 14. A reaction that has one reactant can only be a. a. synthesis reaction b. decomposition reaction c. single-replacement reaction d. double-replacement reaction 15. Atoms rearrange when. a. chemical bonds break b. particles collide with enough energy c. neither a nor b d. both a and b Powered by Cognero Page 2

3 16. Sodium fluoride and silver nitrate become sodium nitrate and silver chloride. Carbonate and hydrogen ions become water and carbon dioxide. This is a reaction. a. synthesis b. decomposition c. single-replacement d. double-replacement 17. According to the law of conservation of mass, how does the mass of the products in a chemical reaction compare to the mass of the reactants? a. There is no relationship. b. The mass of products is sometimes greater. c. The mass of reactants is greater. d. The masses are always equal. 18. What has happened to the water in the illustration? a. The bonds between the water molecules have broken, and the water turned to water vapor. b. The water molecules spread out, and water is turned to water vapor. c. The bonds between the atoms of the water molecule have broken, and the water turned to water vapor. d. The bonds between the atoms of the water molecule have broken, and instead of water, there is now hydrogen and oxygen. 19. Sodium is an atom represented as Na+. What does the + represent? a. The plus sign means it can combine with almost every element found on the periodic table. b. Sodium has a tendency to lose a valence electron when it becomes an ion. c. Sodium has a tendency to gain a valence electron when it becomes an ion. d. One positive sign is listed because it only takes one electron to make the atom neutral. 20. Which equation is balanced? a. H 2 + O 2 H 2 O b. 2Na + Cl2 2NaCl c. CH 4 + 2O 2 CO 2 + H 2 O 21. A single-replacement reaction has. a. one reactant and one product b. one reactant and two products c. two reactants and one product d. two reactants and two products Powered by Cognero Page 3

4 22. Why is the following image representative of a polar molecule? a. The electrons are located at the poles of the molecule chain. b. The valence electrons are shared equally. c. The molecule has an overall positive change. d. The valence electrons are shared unequally. Use the symbols representing types of reactions to answer the following questions. I II III IV 23. Which figure models a synthesis reaction? a. I b. II c. III d. IV 24. Which of the following compounds is NOT likely to have ionic bonds? a. LiF b. NaCl c. CH 4 d. MgF Which situation does NOT occur during chemical reactions? a. Bonds are broken. b. Atoms are created. c. Compounds are formed. 26. Aspartame is an artificial sweetener; its formula is C 13 H 16 N 2 O 5. Which element in the formula has the greatest number of atoms? a. carbon b. hydrogen c. nitrogen d. oxygen Powered by Cognero Page 4

5 27. Which situation does NOT occur during chemical reactions? a. Bonds are broken. b. Bonds are formed. c. Mass is conserved. d. Atoms are destroyed. 28. The maximum number of electrons in the second energy level of an atom is. a. two b. four c. eight d. ten 29. Which of the following is NOT a result of a chemical reaction? a. bubbles in boiling water b. a solid forming from two liquids reacting c. copper turning green when exposed to air d. the light given off by a firefly 30. A chemical bond that occurs when atoms share electrons is a(n) bond. a. covalent b. ionic c. magnetic d. polyatomic 31. Which of the following is a compound? a. gold b. oxygen c. neon d. water 32. The determines the mass of the products of a chemical reaction. a. mass of the reactants b. rate at which the reaction occurs c. number of different products and reactants d. amount of energy absorbed or released by the reaction 33. Which type of molecular model is represented in this image? a. dot diagram b. structural formula c. ball-and-stick model d. space-filling model 34. Which type of reaction is the opposite of a synthesis reaction? a. decomposition b. single-replacement c. double-replacement 35. One property of an ionic bond is. a. the formation of a shiny surface b. the formation of solid crystals c. low melting points d. not dissolving in water Powered by Cognero Page 5

6 36. An ion is an atom that has gained or lost. a. electrons b. protons c. neutrons d. metals 37. Which situation involves a chemical change? a. food rotting b. paper ripping c. water freezing Use the symbols representing types of reactions to answer the following questions. I II III IV 38. Which figure models a double-replacement reaction? a. I b. II c. III d. IV 39. The atoms in the products of a chemical reaction. a. were present in the reactants b. did not exist before the reaction c. were created using energy from the reaction 40. In carbon dioxide, each oxygen atom shares four electrons with the carbon atom. What is this type of bond called? a. triple covalent b. double covalent c. polar covalent d. ionic Powered by Cognero Page 6

7 Answer Key 1. b 2. d 3. c 4. c 5. a 6. b 7. a 8. a 9. a 10. d 11. d 12. a 13. a 14. b 15. d 16. d 17. d 18. d 19. b 20. b 21. d 22. d 23. b 24. c 25. b Powered by Cognero Page 7

8 26. b 27. d 28. c 29. a 30. a 31. d 32. a 33. b 34. a 35. b 36. a 37. a 38. a 39. a 40. b Powered by Cognero Page 8