ESCS Fall Final - Study Guide Name: ______KEY______________________________________________ Period: _____ Date: _________ Unit 1 – Safety & Measurement 1. Why should you clean any dirty glassware before using it for an experiment? Avoid contamination 2. Why do goggles or face shields provide more eye protection than personal eyeglasses? Eyeglasses don’t protect from side splashes. 3. What should you do with long hair in the laboratory? Tie it up. 4. What can happen if you wear loose clothing or jewelry in a laboratory? Catch on things, get contaminated by chemicals 5. What is the best type of footwear to wear in a lab? Closed toed shoes 6. What should you do if a piece of lab equipment is not working properly? Tell the instructor 7. What should you do if acid is splashed on your skin? What if it’s splashed all over your clothes? Skin: Flush with lots of water; Clothes: get them off and flush skin with lots of water 8. Why should you clean your hands after working with chemicals? What should you use to clean them? Chemicals could be on your hands – contamination. Wash with soap and water 9. How does hot glass look compared to cold glass? Same 10. What does it mean if a material is “flammable”? It will easily ignite and burn. 11. What should you do if an uncontrolled fire occurs in the laboratory? Immediately tell the instructor 12. When should you wear special eye protection devices (such as goggles) in the laboratory? Whenever working with chemicals or glassware 13. In the lab, what should you do it you don’t understand a direction or part of a procedure? Ask the instructor 14. What are you supposed to do with chemical wastes after you finish a lab? Dispose of according to instructions from instructor 15. What could happen if you point the end of a test tube that you’re heating towards someone? Material could shoot out the end and hit someone. 16. What’s the best way to pick up a piece of glassware you’ve been heating? With tongs 17. If you get injured in the laboratory (cut, burn, etc.), what should you do? Immediately tell the instructor 18. Why is it important to check glassware for chips or cracks? Cracks and chips weaken glass so it more easily breaks 19. Is it appropriate to return all unused chemicals to their original containers? No 20. Should you start working on a lab even if the instructor is not yet present? No 21. When is okay to remove chemicals or other equipment from the laboratory? Never (only under direct supervision of an instructor) 22. Why are unauthorized experiments prohibited? Potential for unexpected reactions and/or consequences 23. When are students allowed to enter the chemical preparation/storage area? Never 24. Why do people wear laboratory aprons? To protect clothes and skin from chemical splashes/contamination 25. Is it okay to pick up broken glass with your bare hands as long as the glass is placed in the trash? No, ask instructor (who will use tongs and broom with dust pan) 26. Why should you never leave a lit burner unattended? Flame could go out and allow unburned gas to accumulate in room – potential for explosions 27. What instrument is used to weigh objects? Balance 28. What piece of lab equipment is a small glass container used to view chemical reactions or to heat small amounts of a substance? Test Tube 29. What instrument is used to measure volume very precisely? Graduated Cylinder 30. What instrument is a wide-mouthed container used to transport, heat, and store substances? Beaker 31. Define Independent and Dependent Variable (include how they are used when graphing): Independent – X-axis – What cause change Dependent – Y-axis – What changes – what you are measuring 32. What should you do when the data in an investigation do not support the original hypothesis? Modify the hypothesis 33. Provide the SI base units for the following: a. Length – Meter (m) b. Mass – Kilogram (kg) c. Temperature – Kelvin (K) d. Time – Seconds (s) e. Amount of Substance – Mole (mol) f. Electric Current – Ampere (A) g. Luminous Intensity – Candela (cd) 34. Convert the following numbers between standard and scientific notation: a. 2.0094 x 103 = 2,009.4 b. 0.0000945 = 9.45 x 10-5 8 c. 4.603 x 10 = 460,300,000 d. 8.0965 x 10-4 = 0.00080965 e. 90,294 = 9.0294 x 104 f. 0.000000389 = 3.89 x 10-7 g. 390 = 3.9 x 102 35. Determine the number of significant digits in the following numbers: a. 0.00450 = 3 b. 5,795 = 4 c. 100 = 1 d. 50,603,000 = 5 e. 90.0 = 3 f. 1,000,000,500 = 8 g. 0.78210 = 5 h. 0.000800400 = 6 Unit 2 – Matter 36. Define: Matter – ANYTHING THAT HAS MASS AND TAKES UP SPACE Substance – MATTER THAT ALWAYS HAS THE EXTACT SAME COMPOSITION Mixture – 2 OR MORE SUBSTANCE TOGETHER - COMPOSITION CHANGES Element – SUBSTANCE THAT CAN’T BE BROKEN DOWN INTO SIMPLER SUBSTANCES Compound – COMPOSED OF 2 OR MORE ELEMENTS IN FIXED RATIO 37. Name two examples each of an element, and a compound Element: OXYGEN, CARBON, GOLD, SILVER, ETC. Compound: WATER, SALT, SUGAR, CARBON DIOXIDE, SILICON DIOXIDE, ETC. 38. Describe and give an example of each: Heterogeneous mixture: SAND, RIVER WATER, SALSA, CHOCOLATE CHIP COOKIE Homogeneous mixtures. MILK, KOOL-AID, SUGAR COOKIE, GASOLINE Record which picture represents each type: a - HOMOGENEROUS; b - HETEROGENEOUS 39. Define: Solution – HOMOGENOUS MIXTURE OF SOLUTE DISSOLVED IN SOLVENT o Solvent – DOES THE DISSOLVING o Solute – IS DISSOLVED 40. List the 5 basic techniques for separation and describe methods you could use to separate the following mixtures: 1. FILTRATION - Sand and Water: FILTER 2. MAGNET 3. EVAPORTAION - Salt and Water: EVAPORATION 4. DISSOLVING 5. PHYSICAL - Iron and Sulfur: MAGNET 41. Describe the following: (in terms of volume & shape) Solid – FIXED VOLUME; FIXED SHAPE Liquid – FIXED VOLUME; INDEFINITE SHAPE Gas – INDEFINITE VOLUME; INDEFINITE SHAPE 42. Define each of the following (Ex: melting point: substance changes from a _______ to a _________) Freezing point – LIQUID SOLID Boiling point – LIQUID GAS Melting point - SOLID LIQUID 43. List the most common physical and chemical properties: Physical – VISCOSITY, CONDUCTIVITY, MALLEABILITY, HARDNESS, MELTING POINT, BOILING POINT, DENSITY Chemical – FLAMMABILITY, REACTIVITY 44. What are the 3 types of evidence that a chemical change may have occurred? 1. FORMATION OF A GAS 2. FORMATION OF A PERCIPITATE 3. CHANGE IN COLOR 45. Describe these changes as physical or chemical. Substances are…… Mixed P Burned C Melted P Rusted C Cut P Cooked C Spoiled C Dissolved P Digested C Bent P Frozen P Reacted C 46. What happens to the pressure of an enclosed gas if: a. The volume of the container is increased? PRESSURE DECREASES b. The number of particles is increased? PRESSURE INCREASES c. The temperature if lowered? PRESSURE DECREASES DECREASE = LESS COLLISION INCREASE = MORE COLLISION 47. Define Endothermic – ABSORBS ENERGY FROM SURROUNDINGS Exothermic – RELEASES ENERGY INTO SURROUNDINGS Unit 3 – Atomic Structure 48. Subatomic particle descriptions: a. Name the three subatomic particles: proton, neutron, electron b. Give the location where each can be found: nucleus – proton & neutron; electrons in electron cloud c. Give their electric charges: proton is +; electron is - ; neutron is neutral d. Give their relative masses: proton ~ neutron are about equal in mass (1); electron ~1/2000th as much e. Describe the composition and characteristics of the nucleus: protons with (+) and neutrons (neutral) for net + charge; almost all of atom’s mass in nucleus 49. Atomic number and mass number: a. What determines the atomic number of an atom? - # of protons b. What determines the atomic mass of an atom? - # of protons + # of neutrons c. How can you determine how many neutrons will be in a given atom? Atomic mass # – atomic number (i.e. # of protons) = # of neutrons d. For an atom to be neutral, what subatomic particles have to have been present in the same number? – protons (+) and electrons (-) e. What number is unique for any given element? Protons (atomic #) 50. Isotopes & Ions a. Define “isotope”: - atoms of an element with differing numbers of neutrons (and hence, differing atomic mass) b. What is same about all isotopes of a given element? # of protons (& # of electrons in neutral atom) c. What is different between isotopes of a given element? # of neutrons d. Define “ion” – an atom of an element that carries a charge (not neutral) e. How does a neutral atom become an ion? – gaining of losing electrons (gaining = negative charge; losing = positive charge) f. How do you determine the charge of an atom? - # of protons - #of electrons 51. Electron energy levels: a. The number of energy levels filled in an atom is determined by what? What is the new # sequence? – how many electrons the atom has (always fill lowest first); 2, 8, 18, 32 b. What causes an electron to jump to a different energy level? Atom gains or loses energy Unit 4 – Periodic Table 52. What is the definition of atomic mass? Individual Atoms: Number of protons plus number of neutrons. (p+ + n) Elements: Weighted average of the masses of the isotopes. 53. What units do you put on atomic mass? amu (Atomic Mass Units) 1 amu = 1/12 mass of Carbon-12 54. Does the atomic number increase or decrease as you move from left to right? How much does it change from one element to the next? Increases by exactly 1 for each element as you move from left to right 55. The vertical columns on the Periodic Table are called what? Groups or Families (memory aid: families stand up for each other) 56. The horizontal rows are called what? Periods (memory aid: read the row like a sentence and end it with a “period”.) 57. What states of matter are represented by the metals at room temperature (solid, liquid, and/or gas)? Solid and liquid (all but mercury are solids) 58. Every element in the Carbon group (family) has how many valence electrons? 4 59. List 4 properties of metals a. good conductors (heat and electricity) b. solids at room temperature (except mercury) c. malleable and ductile (not brittle) d. luster e. high density (mass per volume) 60. The majority of the Periodic Table is made up of what class of element? metals 61. Which group contains the maximum number of valence electrons, making it the most chemically stable? Noble Gases 62. The chemical and physical properties of Li are most similar to the chemical and physical properties of what other elements? K, Rb, Cs, Fr 63. What is the trend in reactivity within the alkali metals and the alkaline earth metals? Reactivity increases as you go down the column (most reactive elements at the bottom) 64. What is the trend in reactivity within the halogens? Reactivity decreases as you go down the column (most reactive elements at the top) 65. There are two groups (families) on the Periodic Table that are considered the MOST reactive, what are they (give name and number)? Group 1 (IA) – Alkali Metals Groups 17 (VIIA) – Halogens 66. Using your answer from the previous question, how many valence electrons does each of those groups (families) have? Group 1 (IA) – Alkali Metals has 1 valence electron Groups 17 (VIIA) – Halogens has 7 valence electrons 67. Na is a very reactive element in Period 3, what element in Period 2 would be similar in its reactivity? Lithium (both are in group 1 – IA) 68. Looking at Group 2 (IIA) which element would be the MOST reactive? Radium 69. If a reaction is going to take place, which Halogen would you expect to react the fastest? Fluorine 70. If K reacts very violently in water, what you expect Fr to do? React even more violently 71. What do each of the four terms in the element box represent? 55 Cs Cesium 132.91 55 – atomic # Cs – element symbol Cesium – element name 132.91 – atomic mass 72. List the group numbers and names of the families for the Representative elements on the periodic table: 1- Alkali Metals 2- Alkaline Earth Metals 3- Boron Family 4- Carbon Family 5- Nitrogen Family 6- Oxygen Family 7- Halogens or Halides 8- Noble Gasses 73. Use the periodic table to complete the following table: Element # of valence electrons Lewis Dot Diagram Magnesium 2 Oxygen 6 Neon 8 Aluminum 3 74. Draw a Bohr model of Sulfur and Neon. Sulfur Sulfur Neon Neon 16 Protons 10 16 Electrons 10 16 Neutrons 10 Unit 5 – Ionic Bonding 75. What two types of elements will transfer electrons to form an ionic bond? Metal & nonmetal 76. What is an ionic bond? An electrostatic force that holds together a cation and anion 77. How can you describe the electrical charge of an ionic compound? Neutral 78. Metals will lose all of their valence electrons to form a positively charged cation. The oxidation number will be equal to the number of valence electrons. 79. Nonmetals will gain valence electrons to form a negatively charged anion. The oxidation number will be equal to 8 – the # of valence electrons. 80. Which elements are least likely to undergo bonding? Noble Gases 81. Write the oxidation number for the e. Magnesium ___+2____ following elements. f. Barium ___+2____ a. Cesium ___+1____ g. Nitrogen ___-3____ b. Potassium ___+1____ h. Iodine ___-1____ c. Aluminum ___+3____ i. Oxygen ___-2____ d. Iron (III) ___+3____ j. Selenium ___-2____ 82. What properties characterize ionic compounds? High melting point & boiling point Solid at room temperature Brittle Ionic solids can’t conduct electricity Molten ionic compounds can conduct electricity 83. Please draw the transfer of electrons for the following: a. NaBr b. MgO c. CaF2 d. K2S Write the formula for the following ionic compounds: 84. Barium oxide 85. Lithium nitride 86. Magnesium fluoride 87. Lithium phosphate 88. Calcium iodide 89. Copper (II) nitrite 90. Beryllium chloride 91. Gold (III) carbonate 92. Potassium sulfate 93. Calcium hydroxide 94. Barium chloride 95. Lithium oxide 96. Magnesium oxide 97. Calcium fluoride 98. Iron (II) chloride 99. Silver bromide BaO Li3N MgF2 Li3PO4 CaI2 Cu(NO2)2 BeCl2 Au2(CO3)3 K2SO4 Ca(OH)2 BaCl2 Li2O MgO CaF2 FeCl2 AgBr Write the name for the following ionic compounds. Be sure to include parenthesis with Roman numeral for the transition metals: 100. 101. 102. 103. 104. 105. 106. 107. 108. 109. 110. 111. 112. 113. 114. 115. AlBr3 Fe2(SO3)3 MgCl2 K3PO4 TiCl2 Cr2O3 Ag2S Cu(OH)2 Zn3N2 AgNO3 PbF2 Cu2S CaF2 FeCl3 Li3P Au(C2H3O2)3 aluminum bromide iron (III) sulfite magnesium chloride potassium phosphate titanium (II) chloride chromium (III) oxide silver (I) sulfide copper (II) hydroxide zinc (II) nitride silver (I) nitrate lead (II) fluoride copper (I) sulfide calcium fluoride iron (III) chloride lithium phosphide Gold (III) acetate