•                        AP Chemistry- 2020 Summer Assignment

• Answer the questions, Label chapter and question number,  show work for all calculations, Box final answers with units, rounded to correct number of sig figs.
• Do the assignment in a one subject spiral notebook, label with your name.
• Your work should be neat and legible, written with dark pencil or pen. Keep space between answers. Start a new page for each Chapter.
• Work is due the first day of class, following about a week of review, you will be tested on the materials in this assignment.

Chapter 1: The Foundations of Chemistry

1. 58. The specific heat of aluminum is 0.895 J/g ​·​ ​°​C. Calculate the amount of heat required to raise the temperature of 35.1 g of aluminum from 27.0 ​°​C to 62.5 ​°​C.  (865 J)

1. 59. How much heat must be removed from 19.5 g of water at 90.0 ​°​C to cool it to 34.2 ​°​C?  (56 kJ)

1. 60. In some solar-heated homes, heat from the sun is stored in rocks during the day and then released during the cooler night. a. Calculate the amount of heat required to raise the temperature of 69.7 kg of rocks from 25.0 ​°​C to 41.0 ​°​C. Assume that the rocks are limestone, which is essentially pure calcium carbonate. The specific heat of calcium carbonate is 0.818 J/g ​·​ ​°​C. b. Suppose that when the rocks in part (a) cool to 30.0 ​°​C, all the heat released goes to warm the 10,000 ft​3 (2.83 x 10​5​ L) of air in the house, originally at 10.0 ​°​C. To what final temperature would the air be heated? The specific heat of air is 1.004 J/g ​·​ ​°​C, and it’s density is 1.20 x 10-3 ​ g/mL. ( a.16 MJ,  b. 12.5 C)

1. 62. When 50.0 grams of metal at 75.0 ​°​C is added to 100. grams of water at 15.0 ​°​C, the temperature of the water rises to 18.3 ​°​C. Assume that no heat is lost to the surroundings. What is the specific heat of the metal? (73 J/g-c )

1. 65. The radius of a hydrogen atom is about 0.37 Å, and the average radius of the earth’s orbit around the sun is about 1.5 x 10​8​ km. Find the ratio of the average radius of the earth’s orbit to the radius of the hydrogen atom. (4.1x1021 :1)

1. 68. The lethal dose of a specific drug taken orally is 1.5 mg/kg of body weight. Calculate the lethal dose of the drug taken orally by a 165-lb person. (112 mg)

1. 70. Household ammonia is 5% ammonia by mass and has a density of 1.006 g/mL. What volume of this solution must a person purchase to obtain 25.8 g of ammonia? (513 ml)

1. 80. Cesium atoms are the largest naturally occurring atoms. The radius of a cesium atom is 2.65 Å. How many cesium atoms would have to be laid side by side to give a row of cesium atoms 1.00 in. long? Assume that the atoms are spherical. (4.80 x 107 atoms)

Chapter 2: Chemical Formulas and Composition Stoichiometry

1. 12. Name the following compounds:
2. HNO​3 b. C​5​H​12 c. NH​3 d. CH​3​OH

1. 18. Write the chemical formula for the ionic compound formed between each of the following pairs of ions. Name each compound.
2. Cu​2+​ and CO​3​2-     b. Sr​2+​  and Br-    c. NH​4​+​  and CO​3​2-    d. Zn​2+​ and O​2-
3. Fe​3+​ and SO​4​2-

1. 22. Write the formula of the compound produced by the combination of each of the following pairs of elements. Name each compound.
2. Sodium and Chlorine     b. Magnesium and Bromine   c. Sulfur and Oxygen                            d. Calcium and Oxygen       e. Potassium and Sulfur              f. Aluminum and Bromine

1. 30. Determine the formula weight (molecular mass) of each of the following compounds:
2. Hydrogen Sulfide            b. Phosphorous Trichloride                c. Hypochlorous Acid              d. Hydrogen Iodide

1. 38. How many molecules are in 15.5 g of each of the following substances?
2. CO2           b. N2       c. P​4        d. P​2          e. Do parts c. and d. contain the same number of atoms of phosphorous?  ( 2.12x1023 , 3.33x1023 ,.......)

1. 44. What is the mass of 8.00 million methane, CH​4​, molecules? (2.12x10-16 )

1. The beta-blocker drug, timolol, is expected to reduce the need for heart bypass surgery. Its composition by mass is 49.4% C, 7.64% H, 17.7% N, 15.2% O, and 10.1% S. The mass of 0.0100 mol of timolol is 3.16 g.  a. What is the simplest(empirical) formula of timolol?
2. What is the molecular formula of timolol? (C23H24N4O3S )

1. 56. A common product found in nearly every kitchen contains 27.37% sodium, 1.20% hydrogen, 14.30% carbon, and 57.14% oxygen. The simplest formula is the same as the formula of the compound. Find the formula of this compound. ( NaHCO3 )

1. 60. A compound with the molecular weight of 56.0 g was found as a component of photochemical smog. The compound is composed of carbon and oxygen, 42.9% and 57.1%, respectively. What is the formula of this compound? (C2O2 )

1. Calculate the percent composition  of the following compound:

vitamin E -      C​29​H​50​O​2  (80.87%C, 11.70%H, 7.430%O )

1. A 0.1153 gram sample of pure hydrocarbon was burned in a C-H combustion train to produce 0.3986 grams of CO​2​ and 0.0578 grams of H​2​O. Determine the masses of C and H in the sample and the percentage of these elements in this hydrocarbon. (0.1088 g C ,0.00647 g H,  94.36% C, 5.61% H)

1. 70. A 1.000 gram sample of an alcohol was burned in oxygen to produce 1.913 g of CO​2​ and 1.174 g of H​2​O. The alcohol contained only C, H, and O. What is the simplest formula of the alcohol? (C2H6O)

1. When a mole of CuSO​4​ ​·​ 5H​2​O is heated to  110​°​C, it loses four moles of H​2​O to form CuSO​4​ ​·​ H​2​O. When it is heated to temperatures above 150​°​C, the other mole of H​2​O is lost.
2. How many grams of CuSO​4​ ​·​ H​2​O could be obtained by heating 675 g of CuSO​4​ ​·​ 5H​2​O to 110​°​C? b. How many grams of anhydrous CuSO​4​ could be obtained by heating 584 g of CuSO​4​ ​·​ 5H​2​O to 180​°​C?  (480 g ; 373 g )

1. 86. a. What weight of magnesium carbonate is contained in 562 pounds of an ore that is 26.7% magnesium carbonate by weight?   (150. Lb )
2. What weight of impurities is contained in the sample?  (412 lb)
3. What weight of magnesium is contained in the same? (Assume that no magnesium is present in the impurities.)   (43.2 g)

1. 88. a. What is the percent by mass of copper sulfate, CuSO​4​, in a sample of copper sulfate pentahydrate, CuSO​4​ ​· 5H​2​O?   (63.9%)
2. What is the percent by mass of CuSO​4​ in a sample that is 74.4% CuSO​4​ ​·​ 5H​2​O by mass?

(47.6%)

1. 92. Vitamin E is an antioxidant that plays an especially important role protecting cellular structures in the lungs. Combustion of a 0.497 g sample of vitamin E produced 1.47 g of carbon dioxide and 0.518 g of water. Determine the empirical formula of vitamin E.

( C14H24O )

Chapter 3: Chemical Equations and Reaction Stoichiometry

1. 8. Balance each “equation” by inspection.
2. K + O​2​ ​→​ K​2​O                                               b. Mg​3​N​2​ + H​2​O ​→​ NH​3​ + Mg(OH)​2
3. LiCl + Pb(NO​3)2​ ​→​ PbCl​2​ + LiNO​3               d. H​2​O + KO​2​ ​→​ KOH + O​2
4. H​2​SO​4​ + NH​3​ ​→​ (NH​4​)​2​SO​4

1. 14. a. Limestone, CaCO​3​, dissolves in muriatic acid, HCl, to form calcium chloride, CaCl​2​,  carbon dioxide, and water.  b. How many moles of HCl are required to dissolve 5.4 mol of CaCO​3​? c. How many moles of water are formed in part b?  (11 mol HCl, 5.4 mol H2O)

1. 30. Carbon monoxide and oxygen react to give carbon dioxide. 2CO + O​2​ ​→​ 2CO​2 Imagine that we mix six CO molecules and six O​2​ molecules and allow them to react as completely as possible.
2. Draw a molecular representation of the mixture and reactants.
3. Draw a molecular representation of the product mixture, including any remaining reactant molecules.
4. How many grams of CO​2​ can be prepared from 134.67 g of CO and 77.25 g of O​2​? (211.2 g)

1. 36. What is the maximum amount of Ca​3​(PO​4​)​2​ that can be prepared from 12.9 g of Ca(OH)​2​ and 18.37 g of H​3​PO​4​?                 3Ca(OH)​2​ + 2H​3​PO​4​ ​→​ Ca​3​(PO​4​)​2​ + 6H​2​O   ( 18.0 g)

1. When heated, potassium chlorate. KClO​3​, melts and decomposes to potassium chloride and diatomic oxygen.
2. What is the theoretical yield of O​2​ from 3.75 g KClO​3​?   (1.47 g)
3. If 1.05 g of O​2​ is obtained, what is the percent yield?      (71.4%)

1. The reaction of finely divided aluminum and iron(III) oxide, Fe​2​O​3​, is called the thermite reaction. It produces a tremendous amount of heat, making the welding of railroad track possible. The reaction of 500.0 grams of aluminum and 500.0 grams of iron(III) oxide produces 166.5 grams of iron. Fe​2​O​3​ + 2Al ​→​ 2Fe + Al​2​O​3​ + Heat
2. Calculate the mass of iron that should be released by this reaction.   (350.0 g)
3. What is the percent yield of iron? (47.6%)

1. 66. A solution made by dissolving 16.0 g of CaCl​2​ in 64.0 g of water has a density of 1.180 g/mL at 20​°​C.
2. What is the percent by mass of CaCl​2​ in the solution?    (20.0%)
3. What is the molarity of CaCl​2 ​in the solution?     (2.13 M)

1. Commercial concentrated hydrochloric acid is 12.0 M HCl. What volume of concentrated hydrochloric acid is required to prepare 2.50 L of 1.50 M HCl solution?  (0.313 L)

1. 76. Calculate the final volume of solution obtained if 100. mL of 12.0 M NaOH are diluted to 5.20 M.   (231 ml)

1. 82. An excess of AgNO​3​ reacts with 110.5 mL of an AlCl​3​ solution to give 0.215 g of AgCl. What is the concentration, in moles per liter, of the AlCl​3​ solution?

AlCl​3​ + 3AgNO​3​ ​→​ 3AgCl + Al(NO​3​)​3       (0.00452 M)

1. 100. What is the molarity of a solution prepared by mixing 35.0 mL of 0.375 M NaCl solution with a 47.5 mL of a 0.632 M NaCl solution?   (0.523 M)