Description QUESTION 1 Which of the following choices is the most conclusive in determining whether ...
Description QUESTION 1 Which of the following choices is the most conclusive in determining whether a chemical reaction has taken place? a change in color a change in odor a gas was formed a change in the identity of the substance(s) 3 points QUESTION 2 If different products are not created during a process, then a chemical reaction has not occurred. TRUE FALSE 2 points QUESTION 3 Balanced chemical equations provide: the exact quantities of the reactants and products information about how fast the reaction will proceed ratios of atoms, ions, molecules and/or formula units used in the equation an outline of how the substances change from reactants to products 3 points QUESTION 4 The symbol(s) are used to indicate that heat is produced as a result of the reaction. TRUE FALSE 2 points QUESTION 5 From the balanced chemical equations listed below, which equation best expresses the following word equation: The reversible reaction in which solid calcium carbonate yields solid calcium oxide plus carbon dioxide gas? CaCO3 (s) CaO (s) + CO2 (g) CaCO3 (s) CaO (s) + CO2 (g) CaO (s) + CO2 (g) CaCO3 (s) CaClO3 CaClO (s) + O2 (g) 3 points QUESTION 6 From the balanced chemical equations listed below, which equation best expresses the following word equation: Hydrogen gas plus oxygen gas yields water vapor plus energy? 2H2O (g) 2H2 (g) + O2 (g) + energy 2H + O 2HO + energy 2H2 (g) + O2 (g) 2H2O (g) + energy 2H2 (g) + O2 (g) + energy 2H2O (l) 3 points QUESTION 7 Which type of chemical reaction does this equation exemplify? synthesis decomposition double replacement single replacement 3 points QUESTION 8 Which type of chemical reaction does this equation exemplify? synthesis decomposition double replacement single replacement 3 points QUESTION 9 Which type of chemical reaction does this equation exemplify? synthesis decomposition combustion double replacement 3 points QUESTION 10 Match the type of chemical reaction with the appropriate skeleton equation. - A. B. C. D. E. A + B ABRead Answer Items for Question 10 - A. B. C. D. E. AB A + BRead Answer Items for Question 10 - A. B. C. D. E. A + BX AX + BRead Answer Items for Question 10 - A. B. C. D. E. AX + BY AY + BXRead Answer Items for Question 10 - A. B. C. D. E. 2A + O2 2AORead Answer Items for Question 10 Answer A. Single Replacement B. Decomposition C. Synthesis D. Combustion E. Double Replacement QUESTION 1 Balanced chemical equations show: the reactants entering the reaction the products formed by the reaction the ratios of moles needed to balance the reactants and products all of the above 3 points Save Answer QUESTION 2 In the equation, CaCO3 (s) Imported Asset CaO (s) + CO2 (g), the mass of the reactants: is greater than the mass of the products because a gas is released on the product side of the equation is less than the mass of the products because the mass of the gas is not included on the reactant side of the equation is the same as the mass of the products has no relationship to the mass of the products 3 points Save Answer QUESTION 3 When balancing a chemical equation, where should a coefficient be placed? in front of formulas and element symbols in front of individual elements and behind individual compounds behind formulas and element symbols by the lower right hand corner of element or compound formulas, to indicate numbers of atoms 3 points Save Answer QUESTION 4 Coefficients should always: be whole numbers use the lowest possible ratios use the values of 1, 2, 3, or 4 both choices a and b 3 points Save Answer QUESTION 5 What is the molar ratio for the following equation after it has been properly balanced? ____SiO2 + ____C Imported Asset ____ SiC + ____CO Reactants: SiO2 = 1, C = 3; Products: SiC = 1, CO = 2 Reactants: SiO2 = 1, C = 2; Products: SiC = 1, CO = 2 Reactants: SiO2 = 2, C = 3; Products: SiC = 2, CO = 2 Reactants: SiO2 = 3, C = 3; Products: SiC = 3, CO = 2 3 points Save Answer QUESTION 6 What is the molar ratio for the following equation after it has been properly balanced? ____C3H8 + ____O2 Imported Asset ____CO2 + ____ H2O Reactants: C3H8 = 2, O2 = 5; Products: CO2 = 6 and H2O = 4 Reactants: C3H8 = 1, O2 = 5; Products: CO2 = 3 and H2O = 4 Reactants: C3H8 = 1, O2 = 8; Products: CO2 = 3 and H2O = 4 Reactants: C3H8 = 1, O2 = 5; Products: CO2 = 3 and H2O = 5 3 points Save Answer QUESTION 7 What is the atom inventory for the following equation after it has been properly balanced? ____Li + ____BaF2 Imported Asset ____LiF + ____Ba Reactants: Li = 2, Ba = 1, F = 2; Products: Li = 2, Ba = 1, F = 1 Reactants: Li = 1, Ba = 2, F = 2; Products: Li = 1, Ba = 2, F = 2 Reactants: Li = 2, Ba = 1, F = 2; Products: Li = 2, Ba = 1, F = 2 Reactants: Li = 1, Ba = 1, F = 2; Products: Li = 1, Ba = 1, F = 2 3 points Save Answer QUESTION 8 If the combined mass of the reactants is 100 grams, then which of the following MUST be true? the combined mass of the products is 100 grams each product has a mass of 100 grams each reactant has the same mass as each product each reactant must produce 100 grams of product 3 points Save Answer QUESTION 9 In the equation, A + B Imported Asset C + D, if the sum of the masses of reactants A and B is known, and the mass of product C is known, then the mass of product D can be calculated. TRUE FALSE 2 points Save Answer QUESTION 10 Every chemical compound has a formula, which cannot be altered when balancing chemical equations. TRUE FALSE 2 points Save Answer QUESTION 11 A balanced chemical equation must account for every atom involved in a chemical reaction. TRUE FALSE Given the reaction, PCl3 + Cl2 Imported Asset PCl5, if 3.00 moles of Cl2 are used, then how many moles of PCl5 are made?6.00 moles5.00 moles3.00 moles1.00 mole3 points Save AnswerQUESTION 2Given the balanced equation, 2 SO2 + O2 Imported Asset 2 SO3, what is the molar ratio of O2 to SO3?2:11:22:22:33 points Save AnswerQUESTION 3Given the balanced equation, 4 NH3 + 3 O2 Imported Asset 2 N2 + 6 H2O, what is the molar ratio of NH3 to N2?3:24:62:44:23 points Save AnswerQUESTION 4Using the equation, C5H12 + 8O2 Imported Asset 5CO2 + 6H2O, if an excess of pentane (C5H12) were supplied, but only 4 moles of oxygen were available, how many moles of water would be produced?1 mole2 moles3 moles6 moles3 points Save AnswerQUESTION 5Using the equation, C5H12 + 8O2 Imported Asset 5CO2 + 6H2O, if 10 moles of carbon dioxide are produced, how many moles of pentane (C5H12) would need to be supplied?2 moles0.5 mole5 moles10 moles3 points Save AnswerQUESTION 6Using the equation, 4Fe + 3O2 Imported Asset 2Fe2O3, if 8 moles of iron and oxygen from the air were available, how many moles of iron (III) oxide would be produced?4 moles5 moles6 moles8 moles3 points Save AnswerQUESTION 7When magnesium metal and an aqueous solution of hydrochloric acid combine, they produce an aqueous solution of magnesium chloride and hydrogen gas. Using the equation, Mg (s) + 2HCl (aq) Imported Asset MgCl2 (aq) + H2 (g), if 72.9 g of Mg and 146.0 g of HCl are allowed to react, identify the limiting reagent.MgHClMgCl2H23 points Save AnswerQUESTION 8When magnesium metal and an aqueous solution of hydrochloric acid combine, they produce an aqueous solution of magnesium chloride and hydrogen gas. Using the equation, Mg (s) + 2HCl (aq) Imported Asset MgCl2 (aq) + H2 (g), if 24.3 g of Mg and 75.0 g of HCl are allowed to react, calculate the mass of MgCl2 that is produced.75.0 g95.1 g99.3 g104 g3 points Save AnswerQUESTION 9The number of moles of the reagent in excess can be used to calculate the moles of the products of the reaction.TRUEFALSE2 points Save AnswerQUESTION 10In the manufacturing process of sulfuric acid, sulfur dioxide is reacted with oxygen to produce sulfur trioxide. Using the equation, 2SO2 (g) + O2 Imported Asset 2SO3 (g), if 64.06g of sulfur dioxide is given an opportunity to react with an excess of oxygen to produce 75.00 g of sulfur trioxide, what is the percent yield of this reaction?46.83%60.25%75.55%93.68%3 points Save AnswerQUESTION 11Red mercury (II) oxide decomposes to form mercury metal and oxygen gas according to the following equation: 2HgO (s) Imported Asset 2Hg (l) + O2 (g). If 3.00 moles of HgO decompose to form 1.25 moles of O2 and 503 g of Hg, what is the percent yield of this reaction?41.6%62.5%83.3%96.9%3 points Save AnswerQUESTION 12Red mercury (II) oxide decomposes to form mercury metal and oxygen gas according to the following equation: 2HgO (s) Imported Asset 2Hg (l) + O2 (g). If 4.00 moles of HgO decompose to form 1.50 moles of O2 and 603 g of Hg, what is the percent yield of this reaction?26.7%53.4%75.0%95.5%3 points Save AnswerQUESTION 13The percent yield for a chemical reaction can not be calculated until the reaction is completed.TRUEFALSE2 points Save AnswerQUESTION 14The theoretical yield for a chemical reaction can not be calculated until the reaction is completed.TRUEFALSE
