1 Chem 12 Unit 1 Review: Chapters 1-4, 9 1. What are the steps in the Scientific Method? Significant Figures: 2. Counting Significant Figures: Circle the significant figures in the following: a) 5280 feet exactly d) 500 g +/- 100 g b) 0.00005640 cm e) 30.0 ml c) 900.05 km f) 3.9 x 10 8 3. Rounding Off: Round off the following to two significant figures: a) 1.783 d) 23.3790 b) 0.005497 e) 8.2345 x 10 9 c) 656.5 f) 5.3104 x 10-4 Calculations: The least precise measurement will control the answer precision. 4. Multiplication-Division: The quantity with the fewest total digits specifies the number of digits that will be in the answer. Multiply then Round. Divide then Round a) (1.5 )(2.3456 x 10 2 ) = d) = b) 0.0013 x 2233 = e) = 5. Addition-Subtration: Line up columns. The lowest filled column specifies the answer. Round off to the lowest filled column. Add and Round a) 744.09 g b) 321 g 9.126 g 5.971 g +32.0942 g +1.1 g Subtract and Round c) 88.9870 g d) 432.1 g -7.29 g -92.234 g
Scientific Notation: 6. Express the following decimal numbers in scientific notation, (as a coefficient times a power of 10) a) 740. e) 0.394 b) 9280.1 f) 23000 c) 23.081 g) 0.0000000423 d) 7 h) 437.09 7. Multiply (add the exponents) a) (1x109)(1x107 )(1x103 )(1x102)= b) (2.2 x 106)(1.0 x 102)(3.1 x 104) = c) (4 x 105)2 = 8. Divide (subtract the exponents) a) 4 x 10 6 = b) = 9. Compute the following: 2 x 10 a) 8 x 3 x 10 3 2 = b) = 10. Express the following in decimal notation. a) 3.800 x 103 = b) 3.8 x 103 = c) 3.8 x 10-3 = d) 3.80 x 10-3 = e) 6.022 x 1023 = Conversions: 11. Conversion Factor Method or Dimensional Analysis: A) set up the appropriate conversion factor B) calculate the required value C) answer in correct significant figures Do work on your own paper and show all work! a)? m = 0.347 cm x = 0.00347 m or 3.47 x 10-3 m b)? g = 834 kg c)? ml = 0.0253 L d)? g = 5632 mg e)? ft = 50.3 cm f)? g = 2000 lb 12 x 10-5 2 x 10 4 3 x 10-2 2.1 x 10 6 3 x 10 4 1.7 x 10 3 4x 10-4 1 m 100 cm 2
12. More Conversions: g)? mi/hr = 10 m/sec h)? F = 345 C i) How many inches are in 2.5 km? 13. A full box of granola has a mass of 397 g. a) How many ounces of granola will be left after 6 people each are served a 1 oz. serving? b) What is the percent of the original 397 grams remaining? 14. Which physical state demonstrates very low kinetic energy? 15. How many significant figures is the number 4.00700 x 1013? 16. At 20 C the density of mercury is 13.6g/ml. What is the mass of 50.0 ml of mercury at 20 C? 17. Place a P before a physical property or change and a C before a chemical property or change: ice melts at 0 C burning wood silver tarnishes wax melts sulfur smells like rotten eggs crystallizing salt 3 18. What are the steps used when solving a problem by the scientific method? 19. Given the following information, calculate the density of the liquid volume of liquid sample 30.2 ml mass of empty container 75.843 g mass of container and liquid 155.633 g 20. Determine the heat in both calories and joules required to heat 5.32g of water from 14.0 C to 36.3 C. (1.00calorie heats 1.00g of water 1.00 C, 1cal =4.184J) 21. What is the final temperature if one starts with a 4.20g sample of aluminum at 35.2 C and adds 68.5J of energy? (Specific heat of Al = 0.90J/g C) 22. For the following give the name or symbol for the element Antimony Pt Copper Sn Radium Ag Mercury Pb
4 23. Match the words with the descriptions Compound a) the same composition throughout the mixture Molecule b) always has the same invariable composition Atom c) a method of separating a solid from liquid Homogeneous d) contains only one type of atom Metal e) The stored energy that matter possesses related to its position or Element chemical composition Cation f) a separation that uses vaporization of one of the components Heterogeneous g) A change that alters the composition of a substance Alloy h) A negative charged atom or group of atoms Pure Substance i) The term for a direct change in state from a solid to a gas Mixture j) A positive charged atom or group of atoms Distillation k) a mixture with different properties in various regions Anion l) Two or more types of elements in a particular set ratio Chemical change m) A shiny element that has a high density, and is a Sublimation good conductor of heat and electricity Potential Energy n) A homogeneous mixture of two or more metals Filtration o) The smallest particle that represents an element p) Has variable composition and contains two or more substances q) a bonded collection of two or more atoms that may have the same or different elements 24. What is the difference between a theory and a law? 25. What do the following laws state? a) Law of conservation of energy b) Law of conservation of mass c) Law of multiple proportions d) Law of constant composition 26. Name three forms of energy.
27. Write the complete and short electronic configuration. Indicate core electrons by placing brackets around them. Identify and label appropriate valence electrons and pseudocore electrons. Draw the orbital diagrams for the following atoms or ions in their ground states, indicate whether each is paramagnetic or diamagnetic. Mg+2 Sn O I-1 W Be Rb H 28. Write the valence electrons for Se 29. Identify the element whose last electron is 3d8 30. Identify the element whose valence electron is 2s22p3 31. What is an orbital? Describe the shape or draw and label a s and a p orbital 32. How does atomic size increase relative to the periodic table? 33. How does ionization energy increase relative to the periodic table? 34. How does electronegativity increase relative to the periodic table? 35. How does metallic character increase relative to the periodic table? 36. List the halogen group elements 37. List several transition metals 38. Where are the alkaline earth metals? 39. What is Hunds Rule of Multiplicity? (used when drawing orbital diagrams ) 40. What is the Pauli Exclusion Principle? 41. What is the Heisenberg Uncertainty Principle? 42. What evidence contradicted the "Plum Pudding Model" of the atom and what model took its place? 43. What was significant about the atomic emission spectra of atoms and how does it relate to electrons? 44. On the periodic table, groups or families are elements in a (vertical, horizontal) row. 45. Why are atomic masses written on the periodic table not always whole numbers? 5
46. Write the paper on Five atomic models: Dalton's indivisible atom, Thomson s plum-pudding model, Rutherford's nuclear model, Bohr's planetary model, and the Quantum Mechanical Picture model with orbitals Identify the experiments, evidence and people that led to the rise (acceptance) and/or fall (problems) for each of the models of the atom Describe the models of each atom: (draw figures, identify atomic models and characteristics). This should be about 3 to 5 pages on average. Include citations. 47. In which model of the atom did the discovered electrons first appear? 48. Fill in the empty spots 6 mass # (protons +neutrons ) 12 atomic # (number of protons ) 6 C (element symbol ) Symbol # of neutrons # of protons # of electrons atomic mass a) 12 24 Mg +2 13 C b) 6 31 c) 15 P 16 O d) 8 16 O -2 e) 8 f) 20 20 41 g) 15 N 49. Identify whether the following is continuous (C) or quantized (Q). a) a spiral staircase b) an elevated ramp c) a rainbow d) H 2 emission spectrum 50. What is the reference isotope for the atomic mass scale? List both the specific isotope of the atom and its mass in amu (atomic mass units). 51. Calculate the weighted atomic mass of magnesium given the following Mg-26...25.983 amu 11.17% Mg-25...24.986 amu 10.13% Mg-24...23.985 amu 78.70% 52. Which of the following is an impossible designation for an atomic orbital? a) 6s b) 1p c) 3s d) 4f e) 5d 53. Which of the following species is isoelectronic with argon? a) Se-2 b) Br-1 c) S-2 d) K+2 e) Mg+2 54. Order the following atoms from smallest to largest atomic radius. Strontium, Gallium, Francium, Fluorine, Boron, Aluminum, Nitrogen