Chemistry 1 Final Exam Practice Problems 1. What is the difference between the following? a. gas b. liquid c. solid 2. What is a physical change? Chemical Change? 3. What is a homogeneous mixture? Heterogenous mixture? 4. What is a physical property? 5. Convert the following measurements a. 200.010 dm to Hm b. 2.687 x 10-2 m to g c. 240.45 L to kL 6. Turn the following numbers into scientific notation or scientific notation into numbers a. 345,000 g b. 0.000040333 g c. 2.67 x 10 -3 g 7. A brick used in the construction of a pottery kiln is 10.0 cm wide, 5.8 cm tall, and 8,6 cm long. The brick has a mass of 2388 g. (1 cm3 = 1 mL) What is the density of this brick? 8. Use dimensional analysis to answer the following questions. a. 320.05 grams to ounces (16 oz= 1 pound, 453.6 grams= 1 pound) b. 399.0 yards to meters ( 2.54 cm= 1 inch) 9. How many sig figs are in the following numbers? a. 6.0078 x 108 b. 0.000398030 c. 0.00070700 10. Use sig figs to answer the following arithmetic problems a. 8.22 + 3.6 = b. 63.554 - d. 5500 54.1 = c. 9.766 / 3.44 = d. 567.0 x 432 = e. 6.76 + 14= f. 0.0004 x 234.2 = 11. If the true mass of an object is 34.2 g and your balance said 33.9 grams. What would be the percent error? 12. The four isotopes of chromium are shown below, each with a percent abundance and the composition of its nucleus. Using these data, calculate (show work) the average atomic mass for ______________. 12 p+ 12 p+ 12 p+ 12 n0 13 n0 14 n0 78.99 % 10.00 % 11.01% 13. Complete the following table. Be careful with the mass number…it is not atomic mass! Element Symbol Sb Ionic Charge Atomic Number Mass Number Number of Protons 127 52 0 3- 33 0 94 37 Number of Neutrons 75 Number of Electrons 52 50 36 239 14. What is the difference between the atomic mass and the mass number? 15. Write and balance the nuclear equation for the following atoms a. Uranium-242 decays by beta emission b. Gallium- 73 decays by the alpha emission. 16. Write the shorthand electron configuration for the following elements. Use the noble gas base, if you wish. a. Potassium b. Zinc c. Uranium 17. Write the orbital diagram (arrow) for the following elements. You may use the noble gas base if you’d like. a. Oxygen b. Argon c. Barium 18. What is the ground state? When is an electron stable? 19. Answer the following questions about the periodic table. a. Explain why noble gases are inert and do not form ions. b. Identify the name of the group that contains the element fluorine _______________ c. Give the name of the element in the alkali group that has the greatest electron affinity _________. d. Identify the element in the oxygen group whose outermost electrons are in the fourth energy level____. e. Identify the name of a group of elements that contains only metals______________. f. Identify a characteristic that elements in the same period have in common_____________. 20. Answer the following questions about these atoms: a. Which has the smallest atomic radius? Mg or Ba? Explain. b. Which has a smaller radius? As or Br? Explain why. c. Which atom has the lowest ionization energy? Se or Po? Explain. 21. Name the following atoms described by these electron configurations: a. 1s2 2s2 2p6 3s3 b. [Kr] 5s2 4d8 22. Name an element with high ionization energy. _______ Is this most likely to be a cation or anion? _______ Will this ion be larger or smaller than a neutral atom of the same element? ___________ Why? 23. Define the following terms: a. valence electrons 24. Draw the Lewis Structure for the following elements. a. Arsenic b. Boron b. electronegativity c. Neon d. Sodium 25. If an atom has an electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p2, how many valence electrons does it have? 26. Describe the difference structurally between an ionic compound and a covalent compound. 27. Draw the Lewis Structure for the following compounds. Use lines for the covalent molecules and include any bond dipoles present. a. CaF2 b. CHCl3 c. N2 d. CH3NH2 f. Li3P g. HF h. NCl3 j. C2Cl4 28. Draw the Lewis Structure for the following “exceptional” compounds. Use lines for these covalent molecules, and DO NOT include any bond dipoles. a. PF5 b. XeF6 c. BBr3 29. Please name the following compounds: a. HBr b. LiOH c. Cl2O d. HClO3 e. FeCl2 f. (NH4)2 SO3 g. LiBr h. CaBr2 i. Ni3(PO4)2 j. K2CO3 k. PCl5 l. O2 m. Sn(CO3)2 30. Write the chemical formula for each of the following compounds. a. aluminum bromide b. Copper (II) sulfate c. dinitrogen monoxide d. lead (IV) dichromate e. copper II sulfate hexahydrate f. nitrogen gas g. hydrobromic acid h. barium hydroxide i. carbon tetraiodide j. diphosphorus pentaoxide k. ammonia l. strontium oxide m. acetic acid 31. State the VSEPR theory. (State the theory, not just what the letters stand for.) 32. Can a molecule with polar bonds be a nonpolar molecule? Explain. 33. Complete the following table. No need to include molecular dipoles. Name Molecular Structural Formula Formula (include bond dipoles) Phosphorus trifluoride Molecular Shape (Give the Name) Polar/ Nonpolar Molecule PF3 Carbon tetrachloride CCl4 Formaldehyde H2CO Trifluoriomethane CHF3 Carbon dioxide CO2 34. For the following reactions, please balance the equation and state the type of reaction. 1. AgNO3 + CaCl2 2. NH4NO3 N2O 3. FeO Fe2O3 + O2 4. C5H10O2 + O2 + Ca(NO3)2 + H2O CO2 5. Fe(OH)3 + H2SO4 6. Ni + HCl AgCl NiCl2 + H2O Fe2(SO4)3 + + H 2O H2 35. For the following word reactions, please convert them to formulas and then balance the equation and state the type of reaction. a. nitric acid reacts with calcium hydroxide to form calcium nitrate and water. b. C6H6, burns in air (also predict the products) c. magnesium iodide reacts with lithium hydroxide to yield magnesium hydroxide and lithium iodide d. copper metal is added to tin (II) nitrite and forms copper (II) nitrite and tin . 36. Using the given reactants, predict the products, balance the equations, and state the type of reaction. O2 a. C5H10 + b. AlF3 c. Mg H 2O + + d. H2SO4 O2 + Ba(OH)2 e. KClO3 f. Cu + NiCl2 37. a. What is the molar mass of C8H10N4O2? b. What is the percent of N? 38. Determine the percent composition of Ba(NO3)2. 39. How many grams are in 34.26 moles of BaCl2? 40. What is the mass of 17.42 moles of Copper? b. How many atoms is this? 41. How many atoms are in 2174.33 grams of Calcium? 42. How many grams are there in 4.539 x 10 26 molecules of ammonia? 43. The compound CH and C6H6. Which is the empirical formula and which is the molecular formula? 44. If the empirical formula is CO2 and the molecular mass is 176.0 g/mol. What is its molecular formula? 45. Determine the empirical formula of the compound of the following elements: 62.1% C, 5.21 % H, 12.1% N, 20.7% O 46. A compound is found to contain 59.0 % C, 7.1% H, 26.2 % O, and 7.7 % N with a MW of 180 g/mol. a) What is the empirical formula of this compound? b) What is the molecular formula of the compound?