QUESTION 1If you know the number of moles in a sample of a substance, which of the following do you also know about that sample?the mass of that samplethe volume of that samplethe number of representative particles in that samplethe coefficient of the substance when in a chemical reaction3 points Save AnswerQUESTION 2Which contains a greater number of atoms, a mole of silver or a mole of gold?A mole of silver.A mole of gold.They both contain the same number of atoms.The answer cannot be determined without knowing the molar mass of each element.3 points Save AnswerQUESTION 3How many atoms are in 0.788 moles of sodium hydroxide?1.42 x 1024 atoms7.60 x 1023 atoms4.70 x 1023 atoms2.36 x 1023 atoms3 points Save AnswerQUESTION 4How many atoms are in 0.654 moles of lithium chloride?3.93 x 1023 atoms7.87 x 1023 atoms9.20 x 1023 atoms1.18 x 1024 atoms3 points Save AnswerQUESTION 5Determine the molar mass of Ca(OH)2.29.0 g/mol38.0 g/mol57.1 g/mol74.1 g/mol3 points Save AnswerQUESTION 6Which of the following is the molar mass of NaCl?28.00 g/mol58.44 g/mol811.8 g/mol3.500 x 1025 g/mol3 points Save AnswerQUESTION 7If you are given the number of particles in a substance sample, what is the first step you should take to determine how many grams are present in that sample?find the molar mass of the substanceconvert the grams to particlesconvert the moles to massconvert the number of particles to moles3 points Save AnswerQUESTION 8If you are given the mass of a substance sample in grams, what is the first step you should take to determine how many representative particles are in that sample?find the molar mass of the substanceconvert the grams to particlesconvert the mass to molesconvert the moles to particles3 points Save AnswerQUESTION 9Percent composition identifies the amount (in percent) of each element present in a compound.TRUEFALSE2 points Save AnswerQUESTION 10The percent composition of acetic acid, HC2H3O2, is:20% carbon, 2% hydrogen, 27% oxygen40% carbon, 7% hydrogen, 53% oxygen23% carbon, 7% hydrogen, 70% oxygenCannot be determined from the information given3 points Save AnswerQUESTION 11One way to determine the empirical formula of a compound involves using the percent composition of the compound.TRUEFALSE2 points Save AnswerQUESTION 12A compound was analyzed and found to contain only 14 grams of calcium, 11 grams of oxygen and roughly 0.7 grams of hydrogen. What is the empirical formula of the compound?Ca2OHCaOHCaO2HCa(OH)23 points Save AnswerQUESTION 13It is possible to determine the molecular formula without the empirical formula.TRUEFALSE2 points Save AnswerQUESTION 14Phosphoric acid, which is a component of many soft drinks, has a molar mass of 98.00 grams per mole. A sample of phosphoric acid contains 3.1 percent hydrogen, 31.6 percent phosphorus, and 65.3 percent oxygen by mass. What is the molecular formula of phosphoric acid?HPOH2PO2H3PO4H6P2O83 points Save AnswerQUESTION 15In the equation, 2H2 + O2 Imported Asset 2H2O, which substance(s) are the reactant(s)?H2O2H2OH2 and O23 points Save AnswerQUESTION 16Which of the following data does a complete and balanced chemical equation NOT reveal?the molar ratios of each of the reactants and productsthe states of matter for each reactant and productthe correctly written formula for each reactant and productthe mass of each reactant and product3 points Save AnswerQUESTION 17If a reactant or product is part of a water solution, then (aq) is placed as a subscript after the chemical symbol for the substance.TRUEFALSE2 points Save AnswerQUESTION 18Select the properly written and balanced equation for the following chemical reaction: Solid iron (II) sulfide reacts with an aqueous solution of hydrochloric acid to produce hydrogen sulfide gas and solid iron (II) chloride.FeS2 (s)+ 2HCl (aq) Imported Asset 2HS (g) + FeCl2 (s)Fe2S2 (s) + 2HCL(aq) Imported Asset 2HS(g) + Fe2Cl2 (s)FeS (s) + 2HCl (aq) Imported Asset H2S (g) + FeCl2 (s)Fe2S (s) + HCl (aq) Imported Asset HS (g) + Fe2Cl3 points Save AnswerQUESTION 19Select the properly written and balanced equation for the following chemical reaction: Sodium metal and an aqueous solution of magnesium iodide react to produce an aqueous solution of sodium iodide and magnesium metal.Na(s) + MgI (aq) Imported Asset NaI (aq) + Mg(s)Na(s) + MgI2 (aq) Imported Asset NaI2 (aq) + Mg (s)2Na (s) + MgI2 (aq) Imported Asset 2NaI (aq) + Mg (s)2Na (s) + 4MgI (aq) Imported Asset 2NaI2 (aq) + 4Mg(s)3 points Save AnswerQUESTION 20Write the proper word equation to express the following chemical reaction: 4Fe (s) + 3Sn(NO3)4 (aq) Imported Asset 4Fe(NO3)3 (aq) + 3Sn (s).Press Tab to enter the content editor. For the toolbar, press ALT+F10 (PC) or ALT+FN+F10 (Mac).Path: pWords:05 points Save AnswerQUESTION 21What type of reaction is represented by the following chemical equation? CH4 + 2O2 Imported Asset CO2 + 2H2O + heat/lightdouble replacementsingle replacementcombustiondecomposition3 points Save AnswerQUESTION 22Which of the following reactions shows a double replacement reaction for CaBr2 reacting with Na2S?CaBr2 + 2Na2S Imported Asset 2NaSBr + CaCaBr2 + O2 + Na2S Imported Asset CaO2 + 2NaBr + H2SCaBr2 + Na2S Imported Asset 2NaBr + CaSCaBr2 + Na2S Imported Asset 2CaSBr +2Na3 points Save AnswerQUESTION 23Which type of reaction is described by the following equation? 2LiCl + MgO Imported Asset Li2O + MgCl2. Explain your reasoning.Press Tab to enter the content editor. For the toolbar, press ALT+F10 (PC) or ALT+FN+F10 (Mac).Path: pWords:05 points Save AnswerQUESTION 24Which law requires the balancing a chemical equation?Conservation of moleculesConservation of energyConservation of massConservation of elements3 points Save AnswerQUESTION 25Determine the atom inventory for the following equation: 2Na2O Imported Asset 4Na + O2. Does this equation follow the law of conservation of mass?Na = 2, O = 1; Na = 4, O = 1; no, this equation does not follow the law of conservation of massNa = 4, O = 2; Na = 4, O = 2; yes, this equation does follow the law of conservation of massNa = 4, O = 4; Na = 4, O = 2; yes, this equation does follow the law of conservation of massNa = 2, O = 2; Na = 4, O = 2; no, this equation does not follow the law of conservation of mass3 points Save AnswerQUESTION 26In the reaction Fe2O3 + 3CO Imported Asset 2Fe + 3CO2, 10 moles of solid iron and 15 moles of carbon dioxide are produced from 5 moles of iron (III) oxide and 15 moles of carbon monoxide (CO). What is the mole ratio of carbon monoxide to solid iron?15:105:103:22:13 points Save AnswerQUESTION 27Choose the correct coefficients to balance the following equation: __Zn + __HCl Imported Asset __ZnCl2 + __H2.1, 2, 2, 21, 2, 1, 12, 4, 2, 20, 2, 0, 03 points Save AnswerQUESTION 28Choose the correct coefficients to balance the following equation: __CaCO3 + __HCl Imported Asset __CaCl2 + __CO2 + __H2O.1, 2, 1, 1, 12, 4, 2, 1, 12, 2, 1, 2, 11, 2, 1, 1, 23 points Save AnswerQUESTION 29The chemical reaction between aluminum and chlorine produces aluminum chloride:Al (s) + Cl2 (g) Imported Asset AlCl3 (s). 3.0 moles of solid aluminum would be required to react with 3.0 moles of chlorine gas.TRUEFALSE2 points Save AnswerQUESTION 30What is the mole ratio of oxygen to water in the following equation?C3H8 + 5O2 Imported Asset 3CO2 + 4H2O10:810:95:47:73 points Save AnswerQUESTION 31If 5.50 moles of calcium carbide (CaC2) react with an excess of water, how many moles of acetylene (C2H2) will be produced? The balanced equation for this reaction is CaC2 + 2H2O Imported Asset Ca(OH)2 + C2H2.0.0800 moles5.50 moles11.0 moles143 moles3 points Save AnswerQUESTION 32According to the following balanced chemical reaction, CsF(s) + XeF6(s)2 Imported Asset CsXeF7(s), 12.5 moles of CsF are reacted with 10.0 moles of XeF6. How many moles of the product will be produced?10.0 moles12.5 moles3.97 x 103 moles4.96 x 103 moles3 points Save AnswerQUESTION 33One method to produce nitrogen in the lab is to react ammonia with copper (II) oxide: NH3(g) + CuO(s) Imported Asset Cu(s) + H2O(l) + N2(g). After using 40.0 grams of NH3, 15.5 grams of N2 are produced. What is the percent yield of nitrogen in the reaction?
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