Problem 1PE: Practice Exercise 3.1
How many moles of aluminum are there in a 3.47 gram sheet of aluminum foil... Problem 2PE: In a reaction to synthesize nitrogen triiodide. 0.023 mol of I2 are needed. How many grams need to... Problem 3PE: Your laboratory balance can weigh samples to three decimal places. If the uncertainty in your... Problem 4PE: How many atoms of gold are there in one ounce of gold? (Hint: How many grams are in an ounce?) Problem 5PE: What is the average mass of one molecule of table sugar. C12H22O11? Problem 6PE: Most chemistry laboratories have balances that can weigh to the nearest milligram. Would it be... Problem 7PE: Practice Exercise 3.7
Aluminum sulfate is analyzed, and the sample contains 0.0774 moles of sulfate... Problem 8PE: How many moles of nitrogen atoms are combined with 8.60 mol of oxygen atoms in dinitrogen pentoxide? Problem 9PE: Sodium bicarbonate is used to soften water. How many moles of oxygen atoms arc found in 1.29 moles... Problem 10PE: How many grams of iron arc needed to combine with 25.6 g of O to make Fe2O3? (Hint.: Recall the mole... Problem 11PE: Bromine trifluoride explodes upon contact with water. If a sample of bromine trifluoride has 0.163 g... Problem 12PE: When 0.5462 g of a compound was decomposed. 0.2012 g of nitrogen and 0.3450 g of oxygen were... Problem 13PE: An organic compound weighing 0.6672 g is decomposed, giving 0.3481 g carbon and 0.0870 g hydrogen.... Problem 14PE: Calculate the theoretical percentage composition of N2O. (Hint: Recall the definition of percentage... Problem 15PE: Practice Exercise 3.15
Calculate the theoretical percentage compositions for . Which of these... Problem 16PE: A 1.525 g sample of a compound between nitrogen and hydrogen contains 1.333 g of nitrogen.... Problem 17PE: Practice Exercise 3.17
Sulfur forms two different compounds with oxygen, . A 1.525 g sample of a... Problem 18PE: Practice Exercise 3.18
A compound of nitrogen and iodine is an extremely sensitive contact explosive... Problem 19PE: When aluminum it produced by electrolysis we get 5.68 tons of aluminum and 5.04 tons of oxygen. What... Problem 20PE: A white solid used to whiten paper has the following percentage composition: Na, 32.4%; S. 22.6%.... Problem 21PE: Cinnamon gets some of its flavor from cinnamaldehyde that is 81.79% C, 6.10% H, and the rest is... Problem 22PE Problem 23PE Problem 24PE: The empirical formula of hydrazine is NH2 and its molecular mass is 32.0. What is its molecular... Problem 25PE: After determining that the empirical formulas of two different compounds were CH2C1andCHCl, a... Problem 26PE: Practice Exercise 3.26
When aqueous solutions of barium nitrate, , and ammonium phosphate, , are... Problem 27PE: Practice Exercise 3.27
Write the balanced chemical equation that describes what happens when a... Problem 28PE: In the reaction 2SO2(g)+O2(g)2SO3(g), how many moles of O2 are needed to produce 6.76 moles of SO3?... Problem 29PE: Practice Exercise 3.29
How many moles of sulfuric acid, H2SO4, are needed to react with by the... Problem 30PE: Practice Exercise 3.30
Using the information in Example 3.16, calculate the mass of formed under... Problem 31PE: How many grams of carbon dioxide are produced by the reaction described in Example 3.15? Problem 32PE: Practice Exercise 3.32
The reaction between the limestone and hydrochloric acid produces carbon... Problem 33PE: Practice Exercise 3.33
In an industrial process for making nitric acid, the first step is the... Problem 34PE: Practice Exercise 3.34
In the synthesis of aspirin we react salicylic acid with acetic anhydride.... Problem 35PE: Practice Exercise 3.35
Ethanol, , can be converted to acetic acid (the acid in vinegar), , by the... Problem 36PE: In producing a certain drug, one synthetic route involves three steps with percentage yields of... Problem 1RQ: What is the definition of the mole? Problem 2RQ: 3.2 Why are moles used, when all stoichiometry problems could be done using only atomic mass... Problem 3RQ: Which contains more molecules: 2.5molofH2Oor2.5molofH2? Which contains more atoms? Which weighs... Problem 4RQ: How would Avogadros number change if the atomic mass unit were to be redefined as 21027 kg, exactly? Problem 5RQ: 3.5 What information is required to convert grams of a substance into molecules of that same... Problem 6RQ: Using atomic mass units, how would you estimate the number of atoms in a gram of iron? Problem 7RQ: How many moles of iron atoms are in one mole of Fe2O3? How many iron atoms are in one mole of Fe2O3? Problem 8RQ: Write all the mole-to-mole conversion factors that can be written based on the following chemical... Problem 9RQ: What information is required to convert grams of a substance into moles of that same substance? Problem 10RQ: Why is the expression 1.0 mol of oxygen ambiguous? Why doesnt a similar ambiguity exist in the... Problem 11RQ: 3.11 The atomic mass of aluminum is 26.98. What specific conversion factors does this value make... Problem 12RQ: 3.12 If you are given the mass of two elements and the mass of the compound for a sample, how can... Problem 13RQ: How can percentage composition be used to identify a compound? Problem 14RQ: In general, what fundamental information, obtained from experimental measurements, is required to... Problem 15RQ: 3.15 Why can percentage composition be used to determine empirical formula, but not molecular... Problem 16RQ: Why are empirical formulas always used for ionic compounds? Problem 17RQ: 3.17 Under what circumstances can we change, or assign, subscripts in a chemical formula?
Problem 18RQ: How many distinct empirical formulas are shown by the following models for compounds formed between... Problem 19RQ: 3.19 When balancing a chemical reaction, what numbers can be changed? When balancing chemical... Problem 20RQ: When given the unbalanced equation Na(s)+Cl2(g)NaCl(s) and asked to balance it, student A wrote... Problem 21RQ: Give a step-by-step procedure for estimating the number of grams of A required to completely react... Problem 22RQ Problem 23RQ: 3.23 What information is required to determine how grams of sulfur would react with a gram of... Problem 24RQ: A mixture of 0.020 mol of Mg and 0.020 mol of Cl2 reacted completely to form MgCl2 according to the... Problem 25RQ: In a report to a supervisor, a chemist described an experiment in the following way: 0.0800 mol of... Problem 26RQ: On April 16, 1947, in Texas City, Texas, two cargo ships, the Grandcamp and the High Flier, were... Problem 27RQ: What is a limiting reactant? And why does the limiting reactant determine how much product is... Problem 28RQ: Molecules containing A and B react to form AB as shown below. Based on the equations and the... Problem 29RQ: 3.29 Explain why the actual yield is always less than the theoretical yield.
Problem 30RQ Problem 31RQ: 3.31 Determine the mass in grams of each of die following:
(a) 1.35 mol Fe
(b) 24.5 mol O
(c) 0.876... Problem 32RQ: Determine the mass in grams of the following: (a) 0.546 mol S (b) 3.29 mol N (c) 8.11 mol Al Problem 33RQ: 3.33 Calculate the formula mass of each of the following to the maximum number of significant... Problem 34RQ: Calculate the formula mass of each of the following to the maximum number of significant figures... Problem 35RQ: Calculate the mass in grams of the following. (a) 1.25molCa3(PO4)2 (b) 0.600molC4H10 (c) 0.625 mmol... Problem 36RQ: What is the mass in grams of the following? (a) 0.322 mmol POCl3 (b) 4.3110-3mol(NH4)2HPO4 (c) 0.754... Problem 37RQ: Calculate the number of moles of each compound in the following samples. (a) 1.56 ngNH3 (c) 21.5 g... Problem 38RQ: Calculate the number of moles of each compound in the following samples. (a) 4.29gH2O2 (c) 9.36 g... Problem 39RQ: How many moles of nickel are in 17.7 g of Ni? Problem 40RQ: How many moles of chromium are in 85.7 g of Cr? Problem 41RQ: How many moles of tantalum atoms correspond to 1.561021 atoms of tantalum? Problem 42RQ: How many moles of iodine molecules correspond to 1.801024moleculesofI2? Problem 43RQ: 3.43 A nanotechnology experiment requires atoms of potassium. What is the mass of this sample?
Problem 44RQ: What is the mass, in grams, of 41017 atoms of gold present in one nanoparticle? Problem 45RQ: 3.45 How many atoms are in 6.00 g of carbon-12?
Problem 46RQ: How many atoms are in 1.50 mol of carbon-12? How many grams does this much carbon-12 weight? Problem 47RQ: Sucrose (table sugar) has the formula C12H22O11. In this compound, what is the (a) atom ratio of C... Problem 48RQ: Nail polish remover is usually the volatile liquid ethyl acetate, CH3COOC2H5. In this compound, what... Problem 49RQ: 3.79 How many moles of Bi atoms are needed to combine with 1.58 mol of O atoms to make ?
Problem 50RQ: 3.50 How many moles of vanadium atoms, V, are needed to combine with 0.565 mol of O atoms to make... Problem 51RQ: How many moles of Cr are in 2.16 mol of Cr2O3? Problem 52RQ: How many moles of O atoms are in 4.25 mol of calcium carbonate, CaCO3, the chief constituent of... Problem 53RQ: Aluminum sulfate, Al2(SO4)3, is a compound used in sewage treatment plants to remove pollutants by... Problem 54RQ: Magnetite is a magnetic iron ore. Its formula is Fe3O4. (a) Construct a pair of conversion factors... Problem 55RQ: 3.55 How many moles of H2andN2 can be formed by the decomposition of 0.145 mol of ammonia, NH3? Problem 56RQ: 3.56 How many moles of S are needed to combine with 0.225 mol AltogiveAl2S3? Problem 57RQ: 3.57 How many moles of UF6 would have to be decomposed to provide enough fluorine to prepare 1.25... Problem 58RQ: 3.58 How many moles of Fe3O4 are required to supply enough iron to prepare 0.260 mol Fe2O3? (Assume... Problem 59RQ: 3.59 How many atoms of carbon are combined with 4.13 moles of hydrogen atoms in a sample of the... Problem 60RQ: 3.60 How many atoms of hydrogen are found in 2.31 mol of propane, ?
Problem 61RQ: 3.61 What is the total number of C, H, and O atoms in moles of glucose, ?
Problem 62RQ: 3.62 What is the total number of N, H, and O atoms in 0.356 mol of ammonium nitrate, , an important... Problem 63RQ: 3.63 Calcium carbide, CaC2, was once used to make signal flares for ships. Water dripped onto CaC2... Problem 64RQ: 3.64 Iodized salt contains a trace amount of calcium iodate, , to help prevent a thyroid condition... Problem 65RQ: How many moles of nitrogen, N, are in 0.650 mol of ammonium carbonate? How many grams of this... Problem 66RQ: 3.66 How many moles of nitrogen, N, are in 0.556 mol of ammonium nitrate? How many grams of this... Problem 67RQ: 3.67 How many kilograms of a fertilizer made of pure (NH4)2CO3 would be required to supply 1... Problem 68RQ: 3.68 How many kilograms of a fertilizer made of pure P2O5 would be required to supply 1 kilogram of... Problem 69RQ: 3.69 Calculate the percentage composition by mass for each element in the following:
Problem 70RQ: Calculate the percentage composition by mass for each element in the following: (a) (CH3)2N2H2(c)... Problem 71RQ: Which has a higher percentage of oxygen: morphine (C17H19NO3) or heroin (C2lH23NO5)? Problem 72RQ: Which has a higher percentage of nitrogen: carbamaze-pine, an anticonvulsant, (C15HI2N2O) or... Problem 73RQ: Freon is a trade name for a group of gaseous compounds once used as propellants in aerosol cans.... Problem 74RQ: Which has a higher percentage of fluorine: Freon-12 (CC12F2) or Freon 113 (C2C13F3)? Problem 75RQ: It was found that 2.35 g of a compound of phosphorus and chlorine contained 0.539 g of phosphorus.... Problem 76RQ Problem 77RQ: Phencyclidine (angel dust) is C17H25N. A sample suspected of being this illicit drug was found to... Problem 78RQ: The hallucinogenic drug LSD has the molecular formula C20H25N3O. One suspected sample contained... Problem 79RQ: How many grams of O are combined with 7.141021 atoms of N in the compound dinitrogen pentoxide? Problem 80RQ: How many grams of C are combined with 4.251023 atoms of H in the compound C5H12? Problem 81RQ: Write empirical formulas for the following compounds. (a)S2Cl2(d)As2O6(b)C6H12O6(e)H2O2(c)NH3 Problem 82RQ: What are the empirical formulas of the following compounds?... Problem 83RQ: 3.83 Radioactive sodium pertechnetate is used as a brainscanning agent in medicine. Quantitative... Problem 84RQ: A sample of Freon was found to contain 0.423 g of C, 2.50 g of Cl, and 1.34 g of F. What is the... Problem 85RQ: 3.85 Cinnamic acid, a compound related to the flavor component of cinnamon, is carbon, hydrogen,... Problem 86RQ: 3.86 Vanillin, a compound used as a flavoring agent in food products, has the following percentage... Problem 87RQ: A dry-cleaning fluid composed of only carbon and chlorine was found to be composed of 14.5% C and... Problem 88RQ: One compound of mercury with a molar mass of 519 contains 77.26 Hg, 9.25 C, and 1.17 H (with the... Problem 89RQ: When 0.684 g of an organic compound containing only carbon, hydrogen, and oxygen was burned in... Problem 90RQ Problem 91RQ: 3.91 When 6.853 mg of a sex hormone was burned in a combustion analysis, 19.73 mg of and 6.391 mg... Problem 92RQ: When a sample of a compound in the vitamin D family was burned in a combustion analysis, 5.983 mg of... Problem 93RQ: The following are empirical formulas and the masses per mole for three compounds. What are their... Problem 94RQ: The following are empirical formulas and the masses per mole for three compounds. What are their... Problem 95RQ: The compound described in Problem 3.91 was found to have a molecular mass of 290. What is its... Problem 96RQ: 3.96 The compound described in Problem 3.92 was found to have a molecular mass of 399. What is the... Problem 97RQ: A sample of a compound of mercury and bromine with a mass of 0.389 g was found to contain 0.111 g... Problem 98RQ: A 0.6662 g sample of antimonal saffron, which is a red pigment used in painting, was found to... Problem 99RQ: A sample of a compound of C, H, N, and O, was found to have a percentage composition of... Problem 100RQ: 3.100 Strychnine, a deadly poison, has a formula mass of 334 and a percentage composition of and... Problem 101RQ Problem 102RQ: Balance the following equations.... Problem 103RQ: Write the following as balanced chemical equations. (a) Calcium hydroxide reacts with hydrogen... Problem 104RQ: 3.104 Write the following as balanced chemical equations.
(a) Sulfur dioxide reacts with oxygen to... Problem 105RQ Problem 106RQ Problem 107RQ: 3.107 The balanced chemical equation for the combustion of propane, a common heating fuel, is
Draw... Problem 108RQ: 3.108 Draw a molecular-level diagram for the reaction in which sulfur dioxide reacts with molecular... Problem 109RQ: 3.109 Write the equation that expresses in acceptable chemical shorthand the following statement:... Problem 110RQ: The conversion of one air pollutant, nitrogen monoxide, produced in vehicle engines, into another... Problem 111RQ: A balanced chemical equation contains the term 2Ba(OH)28H2O. How many atoms of each element does... Problem 112RQ: 3.112 A balanced chemical equation contains the term “.” How many atoms of each element does this... Problem 113RQ: 3.113 Chlorine is used by textile manufacturers to bleach cloth.
Excess chlorine is destroyed by its... Problem 114RQ: The octane in gasoline burns according to the following equation. 2C8H18+25O216CO2+18H2O (a) How... Problem 115RQ: Propane burns according to the following equation: C3H8+5O23CO2+4H2O (a) How many grams of O2 are... Problem 116RQ: The following reaction is used to extract gold from pre-treated gold ore:... Problem 117RQ: The incandescent white of a fireworks display is caused by the reaction of phosphorus with O2 to... Problem 118RQ: The combustion of butane, C4Hl0, produces carbon dioxide and water. When one sample of C4Hl0 was... Problem 119RQ: In dilute nitric acid, HNO3, copper metal dissolves according to the following equation.... Problem 120RQ: 3.120 The reaction of hydrazine, , with hydrogen peroxide, , has been used in rocket engines. One... Problem 121RQ: Oxygen gas can be produced in the laboratory by decomposition of hydrogen peroxide (H2O2):... Problem 122RQ: Oxygen gas can be produced in the laboratory by decomposition of potassium chlorate (KClO3):... Problem 123RQ: Using the balanced equation 2C2H6S(g)+9O2(g)4CO2(g)+2CO2(g)+6H2O(g) determine the number of SO2... Problem 124RQ: 3.124 Using the balanced chemical equation in Problem 3.123 and the diagram below, determine what... Problem 125RQ: The thermite reaction between powdered aluminum and iron(III) oxide, 2A1+Fe2O3A12O3+2Fe produces so... Problem 126RQ: 3.126 Ethanol is synthesized for industrial use by the following reaction, carried out at very high... Problem 127RQ: 3.127 Silver nitrate, , reacts with iron(III) chloride, to give silver chloride, , and iron(III)... Problem 128RQ: Chlorine dioxide, ClO2, has been used as a disinfectant in air-conditioning systems. It reacts with... Problem 129RQ: Some of the acid in acid rain is produced by the following reaction: 3NO2(g)+H2O(l)2HNO3(aq)+NO(g)... Problem 130RQ: Phosphorus pentachloride reacts with water to give phosphoric acid and hydrogen chloride according... Problem 131RQ: Barium sulfate, BaSO4, is made by the following reaction. Ba(NO3)2(aq)+Na2SO4(aq)BaSO4(s)+2NaNO3(aq)... Problem 132RQ Problem 133RQ: Aluminum sulfate can be made by the following reaction. 2AlCl3(aq)+3H2SO4(aq)Al2(SO4)3(aq)+6HCl(aq)... Problem 134RQ: 3.134 The combustion of methyl alcohol in an abundant excess of oxygen follows the equation
When... Problem 135RQ: Manganese(III) fluoride, MnF3, can be prepared by the following reaction.... Problem 136RQ Problem 137RQ: Mercury is an environmental pollutant because it can be converted by certain bacteria into the... Problem 138RQ Problem 139RQ Problem 140RQ: *3.140 A compound of Ca, C, N, and S was subjected to quantitative analysis and formula mass... Problem 141RQ: 3.141 Ammonium nitrate will detonate if ignited in the presence of certain impurities. The equation... Problem 142RQ: A lawn fertilizer is rated as 6.00% nitrogen, meaning 6.00 g of N in 100 g of fertilizer. The... Problem 143RQ: Nitrogen is the active ingredient in many quick-acting fertilizers. You are operating a farm of 1500... Problem 144RQ: Based solely on the amount of available carbon, how many grams of sodium oxalate, Na2C2O4, could be... Problem 145RQ: According to NASA, the space shuttles external fuel tank for the main propulsion system carries... Problem 146RQ: For a research project, a student decided to test the effect of the lead(II) ion (Pb2+) on the... Problem 147RQ: 3.147 Chlorine atoms cause chain reactions in the stratosphere that destroy ozone that protects the... Problem 148RQ: Lime, CaO, can be produced in two steps as shown in the equations below. If the percentage yield of... Problem 149RQ: A newspaper story describing the local celebration of Mole Day on October 23 (selected for Avogadros... Problem 150RQ: Suppose you had one mole of pennies and you were going to spend 500 million dollars each and every... Problem 151RQ: Using the above two questions as examples, devise a creative way to demonstrate the size of the... Problem 152RQ: 3.152 List the different: ways in which a chemist could use the information used to determine... format_list_bulleted