Q&A Hero

Q: What is oxidized and what is reduced in the following reaction?2Al(s) + 3Br2(g) -> 2AlBr3(s)A) Al is oxidized and Br2 is reduced.B) AlBr3 is reduced and Br2 is oxidized.C) Al is reduced and Br2 isoxidized.D) AlBr3 is reduced and Al is oxidized.E) AlBr3 is oxidized and Al is reduced.

Q: Which of the following is an oxidation-reduction reaction?A) CaCl2 + Na2SO4-> CaSO4 + 2NaClB) KOH + HNO3-> H2O + KNO3C) N2 + O2 -> 2NOD) AgNO3 + NaCl -> AgCl + NaNO3E) Al2(SO4)3 + 6KOH -> 2Al(OH)3 + 3K2SO4

Q: The reaction of methane with oxygen to produce carbon dioxide and water is an example of which class of reaction?CH4(g) + 2O2(g) -> CO2(g) + 2H2O(g)A) single replacementB) double replacementC) combinationD) oxidationE) endothermic

Q: What is the classification for this unbalanced reaction?Fe + HCl -> FeCl3 + H2A) dehydrationB) combinationC) decompositionD) single replacementE) double replacement

Q: The reaction of carbon with oxygen to produce carbon monoxide is an example of which class of reaction?2C(s) + O2(g) -> 2CO(g)A) single replacementB) double replacementC) combinationD) catalyticE) endothermic

Q: What is the classification for this reaction?SO3 (g) + H2O (l) -> H2SO4(l)A) decompositionB) combinationC) replacementD) double replacementE) oxidation reduction

Q: The following reaction takes place when an electric current is passed through water. It is an example of a ________ reaction.2H2O -> 2H2 + O2A) combinationB) single replacementC) dehydrationD) decompositionE) double replacement

Q: In a ________ reaction, two or more elements or compounds form one product. A) decomposition B) single replacement C) dehydration D) double replacement E) combination

Q: Pentane (C5H12) reacts with oxygen (O2) to form carbon dioxide (CO2) and water (H2O) according to the following reaction. Answer the question(s) that follow about this reaction.C5H12 + ? O2 -> ? CO2 + ? H2OWhat is the coefficient for water in the balanced equation?A) 2B) 4C) 5D) 6E) 8

Q: Pentane (C5H12) reacts with oxygen (O2) to form carbon dioxide (CO2) and water (H2O) according to the following reaction. Answer the question(s) that follow about this reaction.C5H12 + ? O2 -> ? CO2 + ? H2OWhat is the coefficient for carbon dioxide in the balanced equation?A) 2B) 4C) 5D) 6E) 8

Q: Pentane (C5H12) reacts with oxygen (O2) to form carbon dioxide (CO2) and water (H2O) according to the following reaction. Answer the question(s) that follow about this reaction.C5H12 + ? O2 -> ? CO2 + ? H2OWhat is the coefficient for oxygen in the balanced equation?A) 2B) 4C) 5D) 6E) 8

Q: In the following reaction, when the equation is correctly balanced, what is the correct coefficient for aluminum chloride?Al(s) + Cl2(g) -> AlCl3(s)A) 1B) 2C) 3D) 4E) 5

Q: In the following reaction, when the equation is correctly balanced, what is the correct coefficient for H2?Fe(s) + HCl(aq) -> FeCl3(aq) + H2(g)A) 1B) 2C) 3D) 4E) 5

Q: In the following reaction, when the equation is correctly balanced, what is the correct coefficient for sodium chloride?Pb(NO3)2(aq) + NaCl(aq) -> PbCl2(s) + NaNO3(aq)A) 1B) 2C) 3D) 4E) 5

Q: In this reaction, what is the coefficient for calcium oxide?CaO(s) + CO2(g) -> CaCO3(s)A) 1B) 2C) 3D) 4E) 5

Q: What is the coefficient of hydrogen, H2, when the following equation is balanced?Al + H2SO4-> Al2(SO4)3 + ? H2A) 1B) 2C) 3D) 4E) 5

Q: What coefficient is placed in front of O2 to complete the balancing of the following equation?C5H8+ ? O2 -> 5CO2 + 4H2OA) 1B) 3C) 5D) 7E) 9

Q: Which of the following correctly gives the best coefficients for the reaction below?N2H4 + H2O2 -> N2 + H2OA) 1, 1, 1 ,1B) 1, 2, 1, 4C) 2, 4, 2, 8D) 1, 4, 1, 4E) 2, 4, 2, 4

Q: Which of the following gives the balanced equation for this reaction?K3PO4 + Ca(NO3)2 -> Ca3(PO4)2 + KNO3A) KPO4 + CaNO3 + KNO3B) K3PO4 + Ca(NO3)2 -> Ca3(PO4)2 + 3KNO3C) 2K3PO4 + Ca(NO3)2 -> Ca3(PO4)2 + 6KNO3D) 2K3PO4 + 3Ca(NO3)2 -> Ca3(PO4)2 + 6KNO3E) K3PO4 + Ca(NO3)2 -> Ca3(PO4)2 + KNO3

Q: In any balanced chemical equation, the number of each type of atom on both sides of the equation is A) doubled. B) the same. C) decreased by one. D) increased by one. E) dependent on the temperature.

Q: A chemical equation is balanced when A) the total number of molecules is the same in reactants and products. B) the total number of ions is the same in reactants and products. C) the sum of the coefficients of the reactants is equal to the sum of the coefficients of the products. D) the number of atoms of each element is the same in reactants and products. E) the charge on each atom is the same in reactants and products.

Q: Identify the letter of the diagram corresponding to the given type of reaction. A B A) Diagram A B) Diagram B 1> endothermic reaction 2> exothermic reaction

Q: Identify the energy associated with each of the labeled parts of the following diagram. A) energy of reactants B) heat of reaction C) activation energy D) energy of products 1> Region A 2> Region B 3> Region C 4> Region D

Q: In an exothermic reaction, heat is a product.

Q: The % yield is the ratio of the theoretical yield to the actual yield multiplied by 100.

Q: In the reaction of hydrogen gas with oxygen gas to produce water, 16.0 g of oxygen gas can produce9.00 g of water, given sufficient hydrogen available.2H2 + O2 -> 2H2O

Q: In the reaction of hydrogen gas with oxygen gas to produce water, 1 mole of oxygen gas can produce 2 moles of water, given sufficient hydrogen available.

Q: The molar mass of copper(II) chloride is 134.5 g.

Q: The molar mass of chlorine gas is 35.5 g.

Q: The mass of one mole of water is 18.0 g.

Q: The molar mass of magnesium is 24.3 g.

Q: The molar mass of silver is 47 g.

Q: Avogadro's number is the number of grams in a mole.

Q: Loss of electrons is an oxidation.

Q: The following is a decomposition reaction.2KClO3 -> 2KCl + 3O2

Q: The following reaction is balanced.KClO3 -> KCl + O2

Q: Acetylene gas, C2H2, reacts with oxygen according to the following equation. If 1.00 mole of acetylene reacts completely with sufficient oxygen, how many moles of carbon dioxide are produced?2C2H2 + 5O2 -> 4CO2 + 2H2O

Q: What is the mass of 1 mole of helium gas?

Q: What is the mass of 1 mole of argon gas?

Q: The molar mass of copper(II) nitrate, Cu(NO3)2 is ________.

Q: The number of particles in 1 mole of hydrogen gas is ________.

Q: What type of reaction is the following?Zn + 2HCl -> ZnCl2 + H2

Q: What type of reaction is the following?2KClO3 -> 2KCl + 3O2

Q: Answer the question that follow about the following reaction.2H2O2 -> 2H2O + O2How many moles of hydrogen peroxide (H2O2) are needed to produce 5.0 moles of water?A) 1.0 moleB) 2.0 molesC) 4.0 molesD) 5.0 molesE) 8.0 moles

Q: Answer the question that follow about the following reaction.2H2O2 -> 2H2O + O2How many grams of hydrogen peroxide (H2O2) are needed to produce 25.0 g of oxygen?A) 106 gB) 26.6 gC) 5.88 gD) 25.0 gE) 53.1 g

Q: Answer the question that follow about the following reaction.2H2O2 -> 2H2O + O2How many grams of water will 100. grams of hydrogen peroxide (H2O2) produce?A) 3600 gB) 360. gC) 5.88 gD) 52.9 gE) 106 g

Q: Answer the question that follow about the following reaction.2H2O2 -> 2H2O + O2How many moles of oxygen gas can 0.88 mole of hydrogen peroxide (H2O2) produce, if decomposition is complete?A) 0.50 moleB) 0.88 moleC) 1.8 molesD) 2.0 molesE) 0.44 mole

Q: Barium chloride and sodium sulfate react according to the following equation.BaCl2 + Na2SO4 -> BaSO4 + 2NaClHow many grams of barium chloride are needed to make 100. grams of barium sulfate?A) 44.9 gB) 89.2 gC) 208.3 gD) 233.3 gE) 46.6 g

Q: Barium chloride and sodium sulfate react according to the following equation.BaCl2 + Na2SO4 -> BaSO4 + 2NaClHow many grams of barium sulfate can be produced from 20.8 g of barium chloride?A) 1.37 gB) 2.33 gC) 23.3 gD) 137 gE) 233 g

Q: Barium chloride and sodium sulfate react according to the following equation.BaCl2 + Na2SO4 -> BaSO4 + 2NaClHow many moles of barium sulfate are produced from 0.100 mole of barium chloride?A) 0.0100 moleB) 0.100 moleC) 0.200 moleD) 1.00 moleE) 2.00 moles

Q: In this reaction, what is the correct coefficient for hydrogen gas?? H2 + ? O2 -> ? H2OA) 1B) 2C) 3D) 4E) 5

Q: A reaction that releases energy as it occurs is classified as a(n) A) endothermic reaction. B) exothermic reaction. C) oxidation-reduction reaction. D) catalyzed reaction. E) decomposition reaction.

Q: The ________ is the minimum energy needed for a chemical reaction to begin. A) reaction energy B) activation energy C) energy of reactants D) energy of products E) heat of reaction

Q: The ________ is the energy difference between reactants and products in a chemical reaction. A) transition energy B) activation energy C) product energy D) overall energy E) heat of reaction

Q: Any reaction that absorbs 150 kcal of energy can be classified as A) endothermic. B) exothermic. C) activated. D) reduction. E) oxidation.

Q: In an endothermic reaction A) heat flows out of the system. B) energy is absorbed by the system. C) the temperature of the system increases. D) the products have less energy that the reactants. E) the products have the same energy that the reactants.

Q: If the reaction shown below is exothermic, the energy level of the reactants isH2 + O2 -> 2H2OA) lower than that of the products.B) higher than that of the products.C) the same as that of the products.D) possibly lower, possibly higher than that of the products.E) higher than the activation energy of the reaction.

Q: For the reaction: 2H2O(l) + 137 kcal -> 2H2 (g) + O2 (g), how many kcal are needed to react 50.0 g H2O(l)?A) 380. kcalB) 137 kcalC) 274 kcalD) 190. kcalE) 760. kcal

Q: For the reaction: 2H2O(l) + 137 kcal -> 2H2 (g) + O2 (g), how many kcal are needed to form 2.00 moles O2 (g)?A) 68.5 kcalB) 137 kcalC) 274 kcalD) 190. kcalE) 548 kcal

Q: How many kcal are produced when 32.0 g of CH4 react?CH4 + 2O2 -> CO2 + 2H2O + 218 kcalA) 218 kcalB) 109 kcalC) 436 kcalD) 6.81 kcalE) 698 kcal

Q: What type of reaction is: CH4 + 2O2 -> CO2 + 2H2O + 218 kcal?A) an endothermic reactionB) an exothermic reactionC) a single replacement reactionD) a combination reactionE) a decomposition reaction

Q: Find the mass of AlCl3 that is produced when 10.0 grams of Al2O3 react with 10.0 g of HCl according to the following equation.Al2O3(s) + 6HCl(aq) -> 2AlCl3(aq) + 3H2O(aq)A) 16.2 gB) 20.0 gC) 12.2 gD) 10.0 gE) 6.10 g

Q: When 60.0 g of CH4 reacts with excess O2, the actual yield of CO2 is 112 g. What is the percent yield?CH4 + 2O2 -> CO2 + 2H2OA) 53.6 %B) 187 %C) 67.9 %D) 46.4 %

Q: When 85.0 g of CH4 are mixed with 160. g of O2 what is the maximum amount of CO2 that can be produced?CH4 + 2O2 -> CO2 + 2H2OA) 2.50 molesB) 5.00 molesC) 5.31 molesD) 7.81 moles

Q: When 10.0 g of NH3 reacts, the actual yield of N2 is 8.50 g. What is the percent yield?4NH3(g) + 6NO(g) -> 5N2(g) + 6H2O(l)A) 85.0%B) 51.5%C) 20.6%D) 41.3%E) 8.5%

Q: When 85.0 g of CH4 are mixed with 160. g of O2 the limiting reactant isCH4 + 2O2 -> CO2 + 2H2OA) CH4.B) O2.C) CO2.D) H2O.

Q: When 3.05 moles of CH4 are mixed with 5.03 moles of O2 the limiting reactant isCH4 + 2O2 -> CO2 + 2H2OA) CH4.B) O2.C) CO2.D) H2O.

Q: How many grams of CO2 are produced from 125 g of O2 and excess CH4?CH4 + 2O2 -> CO2 + 2H2OA) 125 g of CO2B) 62.5 g of CO2C) 172 g of CO2D) 85.9 g of CO2E) 250. g of CO2

Q: How many grams of N2 are produced from 100. g of NH3 in the following reaction?4NH3(g)+ 6NO(g) -> 5N2(g) + 6H2O(l)A) 165 gB) 132 gC) 125 gD) 206 gE) 7.35 g

Q: How many grams of NO are required to produce 145 g of N2 in the following reaction?4NH3(g) + 6NO(g) -> 5N2(g) + 6H2O(l)A) 186 gB) 155 gC) 125 gD) 129 gE) 145 g

Q: Find the mass of AlCl3 that is produced when 25.0 grams of Al2O3 react with excess HCl according to the following equation.Al2O3(s) + 6HCl(aq) -> 2AlCl3(aq) + 3H2O(l)A) 155 gB) 72.9 gC) 65.4 gD) 32.6 gE) 16.3 g

Q: In the reaction of silver nitrate with sodium chloride, how many grams of silver chloride will be produced from 100. g of silver nitrate when it is mixed with an excess of sodium chloride? The equation for the reaction is below.AgNO3(aq) + NaCl(aq) -> AgCl(s) + NaNO3(aq)A) 107.9 gB) 169.9 gC) 84.4 gD) 0.589 gE) 58.9 g

Q: For the question(s) that follow, consider the following balanced equation.Mg3N2(s) + 6H2O(l) -> 3Mg (OH)2(s) + 2NH3(g)How many grams of hydrogen are needed to produce 1.80 g of water according to this equation?2H2 + O2 -> 2H2OA) 0.100 gB) 0.180 gC) 0.200 gD) 2.00 gE) 4.00 g

Q: When 36.0 g of H2O react, how many grams of NH3 are produced? A) 34.0 g B) 10.0 g C) 5.67 g D) 11.3 g E) 102 g

Q: For the question(s) that follow, consider the following balanced equation.Mg3N2(s) + 6H2O(l) -> 3Mg (OH)2(s) + 2NH3(g)How many grams of H2O are needed to produce 150 g of Mg(OH)2?A) 46 gB) 18 gC) 130 gD) 93 gE) 23 g

Q: For the question(s) that follow, consider the following balanced equation.Mg3N2(s) + 6H2O(l) -> 3Mg (OH)2(s) + 2NH3(g)How many grams of MgO are produced when 40.0 grams of O2 react completely with Mg?A) 30.4 gB) 50.4 gC) 60.8 gD) 101 gE) 201 g

Q: For the question(s) that follow, consider the following balanced equation.Mg3N2(s) + 6H2O(l) -> 3Mg (OH)2(s) + 2NH3(g)When 2 moles of Mg3N2 are allowed to react, how many moles of H2O also react?A) 1 moleB) 4 molesC) 6 molesD) 8 molesE) 12 moles

Q: For the question(s) that follow, consider the following balanced equation.Mg3N2(s) + 6H2O(l) -> 3Mg (OH)2(s) + 2NH3(g)What is the correct form of the conversion factor needed to convert the number of moles of H2O to the number of moles of NH3produced?A) B) C) D) E)

Q: In the reaction of nitrogen gas, N2, with hydrogen gas, H2, to form ammonia gas, NH3 , how many moles of hydrogen are needed to react with two moles of nitrogen? A) 2 moles B) 4 moles C) 6 moles D) 8 moles E) 10 moles

Q: When 4 moles of aluminum are allowed to react with an excess of chlorine gas, Cl2, how many moles of aluminum chloride are produced? A) 1 mole B) 2 moles C) 3 moles D) 4 moles E) 5 moles