Q&A Hero

Q: Polyethylene is a polymer consisting of only carbon and hydrogen. If 2.300 g of the polymer is burned in oxygen it produces 2.955 g H2O and 7.217 g CO2. What is the empirical formula of polyethylene? A.CH B.CH2 C.C2H3 D.C5H8 E.C7H8

Q: The combustion of 0.0272 mole of a hydrocarbon produces 1.9609 g H2O and 3.5927 g CO2. What is the molar mass of the hydrocarbon? A.16.0 g/mol B.30.1 g/mol C.44.1 g/mol D.72.2 g/mol E.92.1 g/mol

Q: A 1.5991 g sample of a hydrocarbon is combusted to give 1.6918 g of H2O and 5.1661 g of CO2. What is the empirical formula of the compound? A.CH B.CH2 C.C2H3 D.C3H4 E.C5H8

Q: The reaction of 0.779 g K with O2 forms 1.417 g potassium superoxide, a substance used in self-contained breathing devices. Determine the formula for potassium superoxide. A.KO2 B.KO C.K2O3 D.K2O E.KO4

Q: A 7.3648 g sample of an oxide of mercury, when heated in a stream of hydrogen, produces Hg() and 0.6126 g H2O. What is formula for the compound? A.Hg2O B.HgO C.Hg2O3 D.Hg2O5 E.HgO2

Q: A 1.850 g mixture of SrCO3 and SrO is heated. The SrCO3 decomposes to SrO and CO2. What was the mass percentage of SrCO3 in the mixture if the mass after heating is 1.445 g? A.26.6% B.21.9% C.13.7% D.73.4% E.78.1%

Q: A mixture of MnSO4 and MnSO44H2O has a mass of 2.005 g. After heating to drive off all the water the mass is 1.780 g. What is the mass percent of MnSO44H2O in the mixture? A.11.2% B.34.7% C.65.3% D.69.6% E.88.8%

Q: A mass of 4.561 g of a metal carbonate, MCO3, is heated to drive off carbon dioxide. The remaining metal oxide has a mass of 3.544 g. MCO3(s) MO(s) + CO2(g) What is the identity of the metal? A.Ni B.Ba C.Ca D.Co E.Mg

Q: Sulfur hexafluoride is produced by reacting elemental sulfur with fluorine gas. S8(s) + 24 F2(g) 8 SF6(g) What is the percent yield if 18.3 g SF6 is isolated from the reaction of 10.0 g S8 and 30.0 g F2? A.40.2% B.45.8% C.47.6% D.54.6% E.61.0%

Q: If 15.0 g N2 and 2.00 g H2 react to produce 1.38 g NH3, what is the percent yield of the reaction? N2(g) + 3 H2(g) 2 NH3(g) A.7.57% B.12.2% C.8.12% D.15.1% E.8.17%

Q: Under certain conditions the reaction of ammonia with excess oxygen will produce a 29.5% yield of NO. What mass of NH3 must react with excess oxygen to yield 157 g NO? 4 NH3(g) + 5 O2(g) 4 NO(g) + 6 H2O(g) A.89.1 g B.302 g C.263 g D.26.3 g E.938 g

Q: Aspirin is produced by the reaction of salicylic acid (M = 138.1 g/mol) and acetic anhydride (M = 102.1 g/mol). C7H6O3(s) + C4H6O3() C9H8O4(s) + C2H4O2() If 2.04 g of C9H8O4 (M = 180.2 g/mol) is produced from the reaction of 3.03 g C7H6O3 and 4.01 g C4H6O3, what is the percent yield? A.28.8% B.29.0% C.50.9% D.51.6% E.67.3%

Q: Aspirin (C9H8O4) is produced by the reaction of salicylic acid (M = 138.1 g/mol) and acetic anhydride (M = 102.1 g/mol). C7H6O3(s) + C4H6O3() C9H8O4(s) + C2H4O2() If you react 2.00 g C7H6O3 with 1.60 g C4H6O3, what mass of aspirin (M = 180.2 g/mol) can theoretically be obtained? A.0.40 g B.2.61 g C.2.82 g D.1.53 g E.3.60 g

Q: Magnesium reacts with iodine gas at high temperatures to form magnesium iodide. What mass of MgI2 can be produced from the reaction of 5.15 g Mg and 50.0 g I2? A.29.5 g B.44.9 g C.54.8 g D.55.2 g E.58.9 g

Q: What mass of iron can be produced from the reaction of 175 kg Fe2O3 with 385 kg CO? Fe2O3(s) + 3 CO(g) 2 Fe(s) + 3 CO2(g) A.2.19 kg B.30.6 kg C.61.2 kg D.122 kg E.512 kg

Q: If 5.00 g Br2 and 1.10 g NH3 react according to the equation below, what is the maximum mass of ammonium bromide produced? 3 Br2() + 8 NH3(g) 6 NH4Br(s) + N2(g) A.3.06 g B.6.13 g C.12.9 g D.4.74 g E.8.43 g

Q: Nitric oxide is made from the oxidation of ammonia. What mass of nitric oxide can be made from the reaction of 8.00 g NH3 with 17.0 g O2? 4 NH3(g) + 5 O2(g) 4 NO(g) + 6 H2O(g) A.4.54 g B.12.8 g C.14.1 g D.15.9 g E.25.0 g

Q: How many moles of Mg3P2(s) can be produced from the reaction of 0.14 mol Mg(s) with 0.020 mol P4(s)? 6 Mg(s) + P4(s) 2 Mg3P2(s) A.0.047 mol B.0.14 mol C.0.42 mol D.0.020 mol E.0.040 mol

Q: How many moles of sodium bromide can be produced from the reaction of 1.03 moles of sodium with 0.650 moles of bromine gas? 2 Na(s) + Br2(g) 2 NaBr(s) A.0.650 mol B.1.03 mol C.1.30 mol D.2.06 mol E.0.515 mol

Q: Hydrogen peroxide decomposes into oxygen and water. What mass of oxygen is formed from the decomposition of 125 g of H2O2? A.58.8 g B.66.4 g C.107 g D.118 g E.125 g

Q: What mass of water is produced by the complete combustion of 2.68 grams of ethanol, C2H5OH? A.1.05 g B.1.17 g C.3.14 g D.0.439 g E.20.6 g

Q: The compound P4S3 is used in matches. It reacts with oxygen to produce P4O10 and SO2. The unbalanced chemical equation is shown below. P4S3(s) + O2(g) P4O10(s) + SO2(g) What mass of SO2 is produced from the combustion of 0.401 g P4S3? A.0.134 g B.1.20 g C.0.0389 g D.0.117 g E.0.350 g

Q: Nitroglycerine decomposes violently according to the chemical equation below. What mass of carbon dioxide gas is produced from the decomposition of 5.00 g C3H5(NO3)3? 4 C3H5(NO3)3() 12 CO2(g) + 6 N2(g) +10 H2O(g) + O2(g) A.15.0 g B.0.969 g C.11.6 g D.2.91 g E.0.323 g

Q: If the complete combustion of an unknown mass of ethylene produces 16.0 g CO2, what mass of ethylene is combusted? C2H4(g) + 3 O2(g) 2 CO2(g) + 2 H2O(g) A.0.182 g B.0.364 g C.5.10 g D.8.00 g E.12.6 g

Q: When strongly heated, boric acid breaks down to boric oxide and water. What mass of boric oxide is formed from the decomposition of 15.0 g B(OH)3? 2 B(OH)3(s) B2O3(s) + 3 H2O(g) A.7.50 g B.15.0 g C.8.44 g D.16.9 g E.33.8 g

Q: The reaction of coal and water at a high temperature produces a mixture of hydrogen and carbon monoxide gases. This mixture is known as synthesis gas (or syngas). What mass of water is required for the formation of 175 grams of carbon monoxide? C(s) + H2O(g) H2(g) + CO(g) A.272 g B.315 g C.489 g D.113 g E.175 g

Q: Aluminum reacts with hydrochloric acid to produce aluminum chloride and hydrogen gas. 2 Al(s) + 6 HCl(aq) 2 AlCl3(aq) + 3 H2(g) What mass of H2(g) is produced from the reaction of 0.75 g Al(s) with excess hydrochloric acid? A.0.056 g B.0.084 g C.0.17 g D.1.1 g E.2.3 g

Q: The complete combustion of 0.20 moles of propane, C3H8, will A.consume 0.20 mol O2 and produce 0.20 mol CO2. B.consume 0.20 mol O2 and produce 0.40 mol CO2. C.consume 1.0 mol O2 and produce 0.60 mol CO2. D.consume 1.0 mol O2 and produce 3.0 mol CO2. E.consume 1.0 mol O2 and produce 0.80 mol CO2.

Q: Potassium reacts with chlorine gas to produce potassium chloride. How many moles of K will react with 0.40 moles of Cl2? A.0.20 mol B.0.32 mol C.0.40 mol D.0.60 mol E.0.80 mol

Q: Iron reacts with oxygen to produce iron(III) oxide. 4 Fe(s) + 3 O2(g) 2 Fe2O3(s) If 3.2 moles of Fe react with excess O2, how many moles of Fe2O3 can be formed? A.1.6 mol B.2.4 mol C.3.2 mol D.4.3 mol E.6.4 mol

Q: If an aqueous sodium hydroxide solution is left in contact with air, the concentration of hydroxide ion gradually decreases. The process can be hastened if a person exhales over a sodium hydroxide solution. Write a balanced chemical equation that describes the process by which the hydroxide ion concentration decreases.

Q: Give the name of an acidic oxide and write a balanced chemical equation for the reaction of the oxide with water.

Q: A solution is a homogeneous mixture composed of one or more ____________ dissolved in a solvent.

Q: The net ionic equation for the reaction of barium chloride and sodium sulfate is shown below.Ba2+(aq) + SO42-(aq) BaSO4(s)Chloride and sodium ions are referred to as ________ ions because they are not involved in the reaction.

Q: ________ acid is produced in a larger quantity than any other chemical in the United States. This chemical is used in the production of fertilizers, pigments, alcohol, paper and detergents.

Q: A(n) ________ agent loses electrons in an oxidation-reduction reaction.

Q: All of the following are oxidation-reduction reactions EXCEPT A.CaCO3(s) CaO(s) + CO2(g) B.2 Na(s) + Br2(g) 2 NaBr(g) C.Fe(s) + 2 HCl(aq) FeCl2(aq) + H2(g) D.2 C(s) + O2(g) 2 CO(g) E.2 H2O() 2 H2(g) + O2(g)

Q: Which of the following chemical equations is an acid-base reaction? A.Ba(OH)2(aq) + K2SO4(aq) BaSO4(s) + 2 KOH(aq) B.3 NaOH(aq) + AlCl3(aq) Al(OH)3(s) + 3 NaCl(aq) C.2 H+(aq) + Zn(s) H2(g) + Zn2+(aq) D.2 HCl(aq) + Pb(NO3)2(aq) PbCl2(s) + 2 HNO3(aq) E.H3PO4(aq) + NH3(aq) NH4+(aq) + H2PO4-(aq)

Q: Which of the following chemical equations show oxidation-reduction reactions? 1/ Mg(s) + I2(aq) MgI2(s) 2/ Pb(ClO4)2(aq) + 2 KI(aq) PbI2(s) + 2 KClO4(aq) 3/ Fe2O3(s) + 3 CO(g) 2 Fe(s) + 3 CO2(g) A.1 only B.2 only C.1 and 2 D.1 and 3 E.2 and 3

Q: Which of the following elements generally acts as an oxidizing agent? A.Br2 B.H2 C.Fe D.C E.Li

Q: What is the oxidation number of each atom in sodium hydrogen carbonate, NaHCO3?A.Na = +1, H = -1, C = +6, O = -2B.Na = +1, H = +1, C = +4, O = -2C.Na = +1, H = -1, C = +2, O = -2D.Na = -1, H = +1, C = 0, O = -2E.Na = 0, H = 0, C = 0, O = 0

Q: What is the oxidation number of each atom in sulfurous acid, H2SO3?A.H = +1, S = -2, O = -2B.H = 0, S = +6, O = -2C.H = 0, S = 0, O = 0D.H = +1, S = +4, O = -2E.H = -1, S = +8, O = -2

Q: What is the oxidation number of sulfur in sulfur in H2S?A.-2B.0C.+2D.+4E.+6

Q: What is the oxidation number of iodine in potassium iodate, KIO3?A.-1B.0C.+3D.+5E.+7

Q: Which species is reduced in the reaction below?I-(aq) + ClO-(aq) IO-(aq) + Cl-(aq)A.I-B.H2OC.Cl-D.IO-E.ClO-

Q: Which species in the reaction below undergoes reduction? H2O(g) + CO(g) H2(g) + CO2(g) A.H2O B.CO C.H2 D.CO2 E.None

Q: Which molecule in the reaction below is the oxidizing agent? 2 C2H6(g) + 7 O2(g) 4 CO2(g) + 6 H2O(g) A.C2H6 B.O2 C.H2O D.CO2 E.None

Q: Write a balanced chemical equation for the reaction of aqueous solutions of ammonium sulfate and sodium hydroxide. A.(NH4)2SO4(aq) + 2 NaOH(aq) 2 NH4OH(aq) + SO3(g) + Na2O(aq) B.(NH3)2SO4(aq) + NaOH(aq) 2 NH3(g) + NaOHSO4(aq) C.(NH3)2SO4(aq) + 2 NaOH(aq) 2 NH3(g) + Na2SO4(aq) + 2 OH-(aq) D.(NH4)2SO4(aq) + 2 NaOH(aq) 2 NH4+(g) + Na2SO4(aq) + 2 OH-(aq) E.(NH4)2SO4(aq) + 2 NaOH(aq) 2 NH3(g) + 2 H2O() + Na2SO4(aq)

Q: Write a balanced net ionic equation for the reaction of aqueous solutions of baking soda (NaHCO3) and acetic acid.A.HCO3-(aq) + CH3CO2H(aq) CH3CO2-(aq) + H2O() + CO2(g)B.2 NaHCO3(aq) + CH3CO2H(aq) 2 Na2CO3(aq) + CH4(aq) + 2H2O() + CO2(g)C.NaHCO3(aq) + H+(aq) H2CO3(s) + Na+(aq)D.HCO3-(aq) + H+(aq) H2O() + CO2(g)E.HCO3-(aq) + H+(aq) H2CO3(aq)

Q: Write a balanced net ionic equation for the reaction of calcium sulfide and aqueous nitric acid.A.CaS(s) + 2 H+(aq) Ca2+(aq) + S2-(aq) + H2(g)B.CaS(s) + 2 H+(aq) Ca2+(aq) + H2S(g)C.CaS(s) + 2 HNO3(aq) Ca(NO3)2(aq) + H2S(g)D.CaS(s) + 2 HNO3(aq) Ca(NO3)2(s) + H2S(s)E.S2-(aq) + 2 H+(aq) H2S(g)

Q: Metal oxides react with water to produce ____. A.bases B.hydrogen gas C.oxygen gas D.acids E.hydronium ions

Q: Which of the following compounds will produce a basic solution when dissolved in water? A.CaO B.NaHSO4 C.CO2 D.SO2 E.KCl

Q: Hydrocyanic acid, HCN, is a weak acid. Write a net ionic equation for the reaction of aqueous hydrocyanic acid and aqueous sodium hydroxide.A.HCN(aq) + NaOH(aq) Na+(aq) + CN-(aq) + H2O()B.HCN(aq) + H2O(aq) CN-(aq) + H3O+(aq)C.H+(aq) + OH-(aq) H2O()D.HCN(aq) + OH-(aq) CN-(aq) + H2O()E.H+(aq) + NaOH(aq) Na+(aq) + H2O()

Q: What are the spectator ions in the reaction between aqueous nitric acid and ammonia?A.H+ onlyB.NO3- onlyC.H+ and NH4+D.NO3- and NH4+E.H+, NO3-, and NH4+

Q: What are the spectator ions in the reaction between aqueous hydrobromic acid and aqueous sodium hydroxide?A.Na+ onlyB.H+ and OH-C.Na+ and Br-D.Br- onlyE.H+, Br-, Na+, and OH-

Q: What is the net ionic equation for the reaction of aqueous hydrochloric acid and aqueous potassium hydroxide?A.HCl(aq) + OH-(aq) H2O() + Cl-(aq)B.Cl-(aq) + K+(aq) KCl(s)C.HCl(aq) + KOH(aq) KCl(aq) + H2O()D.Cl-(aq) + K+(aq) KCl(aq)E.H+(aq) + OH-(aq) H2O()

Q: What is the balanced equation for carbonate ion (CO32-) acting as a Brnsted base in a reaction with water?A.CO32-(aq) + 3 H2O() CO44-(aq) + 2 H3O+(aq)B.CO32-(aq) + H2O() HCO3-(aq) + OH-(aq)C.CO32-(aq) + H2O() CO2(g) + 2 OH-(aq)D.CO32-(aq) + 2 H2O() HCO3-(aq) + H3O+(aq)E.CO32-(aq) + H2O() H2CO42-(aq)

Q: Write a balanced equation for the reaction that occurs when hydrogen sulfate ion behaves as a Brnsted-Lowry acid in water.A.HSO4-(aq) + H2O() H2SO4(aq) + H3O+(aq)B.SO42-(aq) + H2O() HSO4-(aq) + OH-(aq)C.HSO4-(aq) + H2O() SO42-(aq) + H3O+(aq)D.HSO4-(aq) + H2O() H2SO4(aq) + OH-(aq)E.H2SO4(aq) + H2O() HSO4-(aq) + H3O+(aq)

Q: Sulfuric acid is the product of the reaction of ____ and H2O.A.SO3B.SO2C.S8D.H2SE.SO42-

Q: Which of the following compounds is a weak base? A.NaOH B.H2CO3 C.LiCl D.NH3 E.CH3CO2H

Q: Which of the following compounds is a weak acid? A.HCl B.H3PO4 C.HNO3 D.HClO4 E.H2SO4

Q: What is the net ionic equation for the reaction of aqueous sodium hydroxide and aqueous iron(II) chloride?A.Na+(aq) + OH-(aq) NaOH(s)B.Na+(aq) + Cl-(aq) NaCl(s)C.Fe2+(aq) + 2 OH-(aq) Fe(OH)2(s)D.Fe2+(aq) + OH-(aq) FeOH+(s)E.Fe2+(aq) + 2 Cl-(aq) FeCl2(s)

Q: What is the net ionic equation for the reaction of aqueous nickel(II) acetate and aqueous sodium carbonate?A.Ni2+(aq) + 2 CH3CO2-(aq) Ni(CH3CO2)2(s)B.Na+(aq) + CH3CO2-(aq) NaCH3CO2(aq)C.Na+(aq) + CH3CO2-(aq) NaCH3CO2(s)D.Ni2+(aq) + CO32-(aq) NiCO3(s)E.Ni2+(aq) + 2 Na+(aq) NiNa2(s)

Q: Write a balanced chemical equation for the reaction of aqueous solutions of magnesium chloride and potassium phosphate. A.MgCl2(aq) + K3PO4(aq) K3Mg(s) + PO4Cl2(aq) B.3 MgCl2(aq) + 2 K3PO4(aq) 3 K2Mg(s) + 2 PO4Cl3(aq) C.MgCl(aq) + KPO4(aq) MgPO4(s) + KCl(aq) D.MgCl2(aq) + 2 KPO4(aq) Mg(PO4)2(s) + 2 KCl(aq) E.3 MgCl2(aq) + 2 K3PO4(aq) Mg3(PO4)2(s) + 6 KCl(aq)

Q: Write a balanced chemical equation for the reaction of aqueous solutions of sodium sulfide and zinc(II) chloride. A.Na2S(aq) + ZnCl2(aq) ZnS(s) + 2 NaCl(aq) B.Na2S(aq) + ZnCl2(aq) ZnS(s) + 2 NaCl(s) C.Na2S(aq) + ZnCl2(aq) Na2Zn(s) + SCl2(aq) D.Na2S(aq) + ZnCl2(aq) Na2Zn(aq) + SCl2(g) E.No reaction occurs.

Q: If an aqueous solution of ____ is added to a mixture of F- and SO42-, the fluoride ion will precipitate, but the sulfate ion will remain in solution.A.LiBrB.HNO3C.Pb(ClO4)2D.MgNO3E.AlCl3

Q: If an aqueous solution of ____ is added to a mixture of Pb2+ and Ba2+, the lead ion will precipitate, but the barium ion will remain in solution. A.NaOH B.Na2SO4 C.K3PO4 D.KCO3 E.Ca(CH3CO2)2

Q: A precipitate will form when aqueous nickel(II) chloride is added to an aqueous solution of ____. A.SrI2 B.Cu(NO3)2 C.KOH D.Na2SO4 E.NaBr

Q: A precipitate will form when aqueous Pb(NO3)2 is added to an aqueous solution of ____. A.Cu(NO3)2 B.NaI C.NaCH3CO2 D.Pb(ClO4)2 E.KNO3

Q: All of the following compounds are insoluble in water except ____. A.BaCO3 B.PbF2 C.Fe(OH)3 D.Ni(ClO4)2 E.PbCrO4

Q: Which of the following compounds are soluble in water: NH4NO3, Fe2S3, CuCO3, and SrCl2? A.NH4NO3 only B.NH4NO3 and Fe2S3 C.Fe2S3 and CuCO3 D.CuCO3 and SrCl2 E.NH4NO3 and SrCl2

Q: Which of the following compounds are soluble in water: K2CO3, CaCO3, NiCO3, and Fe2(CO3)3? A.K2CO3 only B.K2CO3 and CaCO3 C.CaCO3 and NiCO3 D.NiCO3 and Fe2(CO3)3 E.CaCO3, NiCO3, and Fe2(CO3)3

Q: Which of the following statements is/are CORRECT? 1/ Most ionic compounds containing phosphate ion are insoluble in water. 2/ Most ionic compounds containing potassium ion are insoluble in water. 3/ Most ionic compounds containing hydroxide ion are soluble in water. A.1 only B.2 only C.3 only D.1 and 2 E.1, 2, and 3

Q: Which of the following statements is/are CORRECT? 1/ Most ionic compounds containing nitrate ion are soluble in water. 2/ Most ionic compounds containing sulfate ion are insoluble in water. 3/ Most ionic compounds containing carbonate ion are soluble in water. A.1 only B.2 only C.3 only D.1 and 2 E.1, 2, and 3

Q: Which one of the following compounds is a nonelectrolyte when dissolved in water? A.HCl B.CaCl2 C.CCl4 D.Cu(NO3)2 E.NaCH3CO2

Q: Which of the following statements is/are CORRECT? 1/ Water soluble ionic compounds, such as NaCl, are strong electrolytes. 2/ Some molecular compounds, such as HCl, are strong electrolytes. 3/ Some molecular compounds, such as acetic acid, are weak electrolytes. A.1 only B.2 only C.3 only D.1 and 2 E.1, 2, and 3

Q: Which of the following statements is/are CORRECT? 1/ All ionic compounds that are soluble in water are electrolytes. 2/ All ionic compounds dissolve in water. 3/ Molecular compounds are never soluble in water. A.1 only B.2 only C.3 only D.1 and 2 E.2 and 3

Q: Which of the following statements is/are CORRECT? 1/ A solution is a homogeneous mixture of two or more substances. 2/ A solute is a mixture of a solvent and a soluble compound. 3/ Aqueous solutions are solutions in which water is a solvent. A.1 only B.2 only C.3 only D.1 and 2 E.1 and 3

Q: What is the balanced chemical equation for the complete combustion of benzoic acid, C6H5CO2H, to form carbon dioxide and water? A.C6H5CO2H(s) 6 C(s) + CO2(g) + 3 H2(g) B.C6H5CO2H(s) 7 CO2(g) + 3 H2O(g) C.C6H5CO2H(s) + O2(g) CO2(g) + H2O(g) D.C6H5CO2H(s) + 8 O2(g) 7 CO2(g) + 3 H2O(g) E.2 C6H5CO2H(s) + 15 O2(g) 14 CO2(g) + 6 H2O(g)

Q: The products of the complete combustion of octane, C8H18, are carbon dioxide and water. Write a balanced chemical equation for this reaction. A.C8H18() 8 C(s) + 9 H2(g) B.C8H18() + 25 O2(g) 8 CO2 (g) + 9 H2O(g) C.2 C8H18() + 25 O2(g) 16 CO2(g) + 18 H2O(g) D.C8H18() + 16 O2(g) 8 CO2(g) + 9 H2(g) E.2 C8H18() + 17 O2(g) 16 CO(g) + 18 H2O(g)