103 + Interview Questions in The Chemical Reaction Equation & Stoichometry in Basic Chemical Engineering Page 2 InterviewSolution

51.	A reactor is supplied with C6H12O6 and the following reactions occur C6H12O6 -> 2C2H5OH + 2CO2 and C6H12O6 –> 2C2H3CO2H + 2H2O, 360 grams of pure glucose is supplied and 44 grams of CO2 was produced, what 90 grams of glucose left unreacted, how many grams of water was produced?(a) 9(b) 18(c) 36(d) 54The question was posed to me at a job interview.Origin of the question is Processes Involving Multiple Units in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct choice is (a) 9 To ELABORATE: Weight of glucose reacted in first reaction = ½(66/44)180 = 135 grams => Weight of glucose reacted in second reaction = 360 – 180 – 135 = 45 grams, => MOLES of water produced = 2(45/180)18 = 9 grams.

Discussion

52.	A reactor is supplied with C6H12O6 and the following reactions occur C6H12O6 -> 2C2H5OH + 2CO2 and C6H12O6 –> 2C2H3CO2H + 2H2O, 360 grams of pure glucose is supplied and 44 grams of CO2 was produced, what 90 grams of glucose left unreacted, how many grams of ethanol was produced?(a) 23(b) 46(c) 92(d) 186I got this question in final exam.This interesting question is from Processes Involving Multiple Units topic in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct choice is (b) 46 Explanation: Moles of glucose REACTED in first REACTION = 90/180 = 0.5, => weight of ETHANOL produced = 20.546 = 46 grams.

Discussion

53.	A reactor is supplied with C6H12O6 and the following reactions occur C6H12O6 -> 2C2H5OH + 2CO2 and C6H12O6 –> 2C2H3CO2H + 2H2O, 360 grams of pure glucose is supplied and 44 grams of CO2 was produced, what 90 grams of glucose left unreacted, how many grams of propenoic acid was produced?(a) 18(b) 36(c) 72(d) 144This question was addressed to me in an interview for internship.I'm obligated to ask this question of Processes Involving Multiple Units topic in division The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct answer is (d) 144 The explanation: WEIGHT of glucose REACTED in first reaction = (44/44)(1/2)180 = 90 grams, => (360 – 90 – 90) = 180 grams of glucose reacted in SECOND reaction, => weight of propenoic acid PRODUCED = 2(180/180)72 = 144 grams.

Discussion

54.	A reactor is supplied with 5 moles each of CH3OH and O2, and the following reactions occur, CH3OH + 1/2O2 -> CH2O + H2O and then CH2O + 1/2O2 -> CO + H2O, the conversion of methanol is 80% in first reaction, and conversion of CH2O is 50% in second reaction. How many moles of CH3OH are there in the products?(a) 1(b) 2(c) 3(d) 4This question was addressed to me during an interview.My enquiry is from Processes Involving Multiple Units topic in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» CORRECT OPTION is (a) 1 For EXPLANATION I would say: Extent of reaction E1 = (-0.8)/(-1) = 0.8, E2 = (-0.5)/(-1) = 0.5, => moles of CH3OH = 5 – 5*0.8 = 1.

Discussion

55.	A reactor is supplied with 5 moles each of CH3OH and O2, and the following reactions occur, CH3OH + 1/2O2 -> CH2O + H2O and then CH2O + 1/2O2 -> CO + H2O, the conversion of methanol is 80% in first reaction, and conversion of CH2O is 50% in second reaction. How many moles of O2 are there in the products?(a) 1.75(b) 2(c) 3.25(d) 5.5This question was posed to me in an international level competition.Enquiry is from Processes Involving Multiple Units in division The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct CHOICE is (a) 1.75 The BEST explanation: EXTENT of REACTION E1 = (-0.8)/(-1) = 0.8, E2 = (-0.5)/(-1) = 0.5, => moles of O2 = (2.5 – 2.50.8) + (2.5 – 2.50.5) = 1.75.

Discussion

56.	A reactor is supplied with 5 moles each of CH3OH and O2, and the following reactions occur, CH3OH + 1/2O2 -> CH2O + H2O and then CH2O + 1/2O2 -> CO + H2O, the conversion of methanol is 80% in first reaction, and conversion of CH2O is 50% in second reaction. How many moles of CH2O came out of the reactor?(a) 1(b) 2(c) 3(d) 4I got this question in an interview.Enquiry is from Processes Involving Multiple Units topic in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct OPTION is (b) 2 Easiest explanation: EXTENT of reaction E1 = (-0.8)/(-1) = 0.8, E2 = (-0.5)/(-1) = 0.5, => moles of CH2O unreacted = 0.85 – (0.85)*0.5 = 2.

Discussion

57.	A reactor is supplied with 5 moles each of CH3OH and O2, and the following reactions occur, CH3OH + 1/2O2 -> CH2O + H2O and then CH2O + 1/2O2 -> CO + H2O, the conversion of methanol is 80% in first reaction, and conversion of CH2O is 50% in second reaction. How many moles of CO are produced?(a) 1(b) 2(c) 3(d) 4I got this question in an interview.My question is from Processes Involving Multiple Units topic in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Right choice is (B) 2 Explanation: Extent of REACTION E1 = (-0.8)/(-1) = 0.8, E2 = (-0.5)/(-1) = 0.5, => MOLES of CO = (0.85)0.5 = 2.

Discussion

58.	A reactor is supplied with 5 moles each of CH3OH and O2, and the following reactions occur, CH3OH + 1/2O2 -> CH2O + H2O and then CH2O + 1/2O2 -> CO + H2O, the conversion of methanol is 80% in first reaction, and conversion of CH2O is 50% in second reaction. How many moles of H2O are produced?(a) 2(b) 3(c) 5(d) 6I had been asked this question in an internship interview.Query is from Processes Involving Multiple Units topic in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The correct choice is (d) 6 The best explanation: EXTENT of REACTION E1 = (-0.8)/(-1) = 0.8, E2 = (-0.5)/(-1) = 0.5, => moles of H2O = (0.85) + (0.85)*0.5 = 6.

Discussion

59.	A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO2, 25% N2 and stream-2 containing pure H2S, if the product has 1200 grams of S, and the ratio of H2S to H2O is 5 and the ratio of SO2 to H2S is 2, what is percentage of Sulfur in the product?(a) 23%(b) 47%(c) 61%(d) 84%This question was addressed to me by my college director while I was bunking the class.I would like to ask this question from Species Material Balances in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct choice is (C) 61% Easiest explanation: The reaction is 2H2S + SO2 -> 3S + H2O, => EXTENT of reaction, E = (1200/32)/3 = 12.5, Let the rate be F. nSO2p = 2nH2Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles. => Moles of SO2 = 0.75F – E = 10, moles of H2S = F – 2E = 5, moles of N2 = 7.5, moles of S = 37.5, moles of H2O = 1, => percentage of sulfur = 61%.

Discussion

60.	A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO2, 25% N2 and stream-2 containing pure H2S, if the product has 1200 grams of S, and the ratio of H2S to H2O is 5 and the ratio of SO2 to H2S is 2, what fraction of excess reagent is converted into product?(a) 0.23(b) 0.55(c) 0.74(d) 0.87I got this question in an interview for internship.This question is from Species Material Balances topic in division The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct option is (b) 0.55 The best explanation: The reaction is 2H2S + SO2 -> 3S + H2O, => extent of reaction, E = (1200/32)/3 = 12.5, Let the rate be F. nSO2p = 2nH2Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles. => The excess reagent is SO2, => fraction of SO2 converted into product = E/0.75F = 12.5/(0.75*30) = 0.55.

Discussion

61.	A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO2, 25% N2 and stream-2 containing pure H2S, if the product has 1200 grams of S, and the ratio of H2S to H2O is 5 and the ratio of SO2 to H2S is 2, how many moles of water are produced?(a) 1(b) 2(c) 3(d) 4This question was addressed to me in an interview for job.This interesting question is from Species Material Balances topic in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The correct choice is (a) 1 Explanation: The REACTION is 2H2S + SO2 -> 3S + H2O, => extent of reaction, E = (1200/32)/3 = 12.5, LET the rate be F. nSO2p = 2nH2Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles. 5nH2Op = nH2Sp, => 5 nH2Op = 30 – 2(12.5) = 5, => nH2Op = 1.

Discussion

62.	A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO2, 25% N2 and stream-2 containing pure H2S, if the product has 1200 grams of S, and the ratio of H2S to H2O is 5 and the ratio of SO2 to H2S is 2, what is the rate of streams?(a) 10 mole(b) 20 moles(c) 30 moles(d) 40 molesThe question was posed to me in semester exam.I want to ask this question from Species Material Balances topic in division The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct option is (c) 30 moles The best explanation: The reaction is 2H2S + SO2 -> 3S + H2O, => EXTENT of reaction, E = (1200/32)/3 = 12.5, Let the rate be F. nSO2p = 2nH2Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles.

Discussion

63.	A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO2, 25% N2 and stream-2 containing pure H2S, if the product has 1200 grams of S, and the ratio of H2S to H2O is 5 and the ratio of SO2 to H2S is 2, what fraction of limiting reagent is converted into product?(a) 0.21(b) 0.46(c) 0.73(d) 0.83The question was asked in exam.This key question is from Species Material Balances in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The correct answer is (d) 0.83 For explanation: The reaction is 2H2S + SO2 -> 3S + H2O, => extent of reaction, E = (1200/32)/3 = 12.5, Let the rate be F. nSO2p = 2nH2Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles, => limiting REAGENT is H2S, => fraction of H2S converted into PRODUCT = 2E/F = 2(1.25)/3 = 0.83.

Discussion

64.	A reactor is supplied with a feed of composition 46% C3H7O4, 44% O2 and 10% N2, if 50% of the limiting reagent is converted into product, what is the percentage of H2O in the product?(a) 15(b) 23(c) 39(d) 51I got this question by my school teacher while I was bunking the class.The query is from Species Material Balances topic in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct answer is (b) 23 The BEST I can explain: The reaction is 4C3H7O4 + 11O2 -> 12CO2 + 14H2O, => Limiting REAGENT is O2. Let 100 moles of feed was supplied, => after the reaction, moles of CO2 = 24, moles of H2O = 28, moles of O2 = 22, moles of C3H7O4 = 38, moles of N2 = 10, => percentage of H2O = 23%.

Discussion

65.	A reactor is supplied with a feed of composition 46% C3H7O4, 44% O2 and 10% N2, if 50% of the limiting reagent is converted into product, what is the percentage of C3H7O4 in the product?(a) 10(b) 16(c) 31(d) 43The question was posed to me in an online quiz.My enquiry is from Species Material Balances topic in portion The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct option is (c) 31 Best EXPLANATION: The reaction is 4C3H7O4 + 11O2 -> 12CO2 + 14H2O, => Limiting reagent is O2. Let 100 moles of feed was supplied, => after the reaction, moles of CO2 = 24, moles of H2O = 28, moles of O2 = 22, moles of C3H7O4 = 38, moles of N2 = 10, => percentage of C3H7O4 = 31%.

Discussion

66.	A reactor is supplied with a feed of composition 46% C3H7O4, 44% O2 and 10% N2, if 50% of the limiting reagent is converted into product, what is the percentage of O2 in the product?(a) 10(b) 18(c) 38(d) 54The question was posed to me by my college director while I was bunking the class.My question comes from Species Material Balances topic in portion The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The correct option is (b) 18 The EXPLANATION is: The reaction is 4C3H7O4 + 11O2 -> 12CO2 + 14H2O, => Limiting reagent is O2. Let 100 moles of feed was SUPPLIED, => after the reaction, moles of CO2 = 24, moles of H2O = 28, moles of O2 = 22, moles of C3H7O4 = 38, moles of N2 = 10, => percentage of O2 = 18%.

Discussion

67.	A reactor is supplied with a feed of composition 46% C3H7O4, 44% O2 and 10% N2, if 50% of the limiting reagent is converted into product, what is the percentage of N2 in the product?(a) 8(b) 18(c) 34(d) 46This question was addressed to me in an international level competition.This is a very interesting question from Species Material Balances in division The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Right choice is (a) 8 For explanation: The reaction is 4C3H7O4 + 11O2 -> 12CO2 + 14H2O, => Limiting reagent is O2. Let 100 MOLES of FEED was supplied, => after the reaction, moles of CO2 = 24, moles of H2O = 28, moles of O2 = 22, moles of C3H7O4 = 38, moles of N2 = 10, => percentage of N2 = 8%.

Discussion

68.	A reactor is supplied with a 100 mole feed of composition 46% C3H7O4, 44% O2 and 10% N2, if 50% of the limiting reagent is converted into product, what is the extent of reaction?(a) 1(b) 2(c) 3(d) 4I have been asked this question in unit test.The above asked question is from Species Material Balances topic in portion The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct answer is (B) 2 The explanation is: The reaction is 4C3H7O4 + 11O2 -> 12CO2 + 14H2O, => LIMITING reagent is O2, => EXTENT of reaction = (44*0.5 – 44)/(-11) = 2.

Discussion

69.	A reactor is supplied with 5 moles of KNO3 and some H2SO4, if the extent of reaction is 2, how many moles of H2SO4 were supplied?(a) 1(b) 2(c) 5(d) Cannot be determinedThis question was addressed to me during an interview for a job.Origin of the question is Species Material Balances topic in division The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The CORRECT OPTION is (d) Cannot be determined To explain: SINCE the final moles of H2SO4 are not GIVEN, initial moles cannot be determined.

Discussion

70.	A reactor is supplied with 10 moles of O2 and 10 moles of H2, if the extent of reaction is 5, how many moles of water is produced?(a) 5(b) 10(c) 15(d) 20I had been asked this question in examination.This interesting question is from Species Material Balances in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The CORRECT answer is (b) 10 For EXPLANATION I would say: The chemical reaction is 2H2 + O2 -> 2H2O, => moles of H2O produced = 5*2 = 10.

Discussion

71.	A reactor is supplied with 6 moles of N2 and 9 moles of H2, if 3 moles of NH3 is produced, how many moles of H2 are left at the end?(a) 1.5(b) 3(c) 4.5(d) 6I have been asked this question in examination.The query is from Species Material Balances in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The CORRECT option is (C) 4.5 Easy explanation: The REACTION is N2 + 3H2 -> 2NH3, => extent of reaction = (3 – 0)/2 = 1.5, => moles of H2 left = 9 – 1.5*3 = 4.5.

Discussion

72.	A reactor is supplied with 10 moles of CH4 and 10 moles of O2, if the extent of reaction is 3, what are the moles of CO2 produced?(a) 3(b) 6(c) 8(d) 12This question was addressed to me in examination.Question is from Species Material Balances topic in portion The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» CORRECT answer is (a) 3 Explanation: The chemical REACTION is CH4 + 2O2 -> CO2 + 2H2O, => MOLES of CO2 produced = 3*1 = 3.

Discussion

73.	A reactor is supplied with 6 moles of CO and 3 moles of O2 and produced 4 moles of CO2, what is the extent of reaction?(a) 1(b) 2(c) 3(d) 4This question was posed to me during a job interview.My doubt stems from Species Material Balances topic in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Right choice is (b) 2 To elaborate: The reaction is 2CO + O2 -> 2CO2, => Extent of reaction = (4 – 0)/2 = 2.

Discussion

74.	1 mole of potassium permanganate and 1 mole of ferrous sulfide are reacted in presence of excess hydrochloric acid, how many moles of Ferric sulfate will produce?(a) 10/18(b) 5/18(c) 1/18(d) 1/36This question was addressed to me in final exam.This intriguing question originated from Stoichiometry Applications Terminology in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct CHOICE is (b) 5/18 The EXPLANATION is: The balanced chemical reaction is 18KMnO4 + 10FeS + 32H2SO4 -> 18MnSO4 + 5Fe2(SO4)3 + 9K2SO4 + 32H2O, => KMNO4 is limiting reagent, => moles of Fe2(SO4)3 = (5/18)*1 = 5/18.

Discussion

75.	10 grams of NaCl and 1.8 grams of H2O are reacted, how much sodium hydroxide will produce?(a) 4 grams(b) 10 grams(c) 40 grams(d) 80 gramsI have been asked this question in a job interview.Origin of the question is Stoichiometry Applications Terminology topic in division The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The CORRECT answer is (a) 4 grams For explanation I would say: The balanced chemical reaction is NaCl + H2O -> NaOH + HCl, in this CASE H2O is a LIMITING REAGENT, => moles of NaOH = moles of H2O = 1.8/18 = 0.1, => weight of NaOH = 0.1*40 = 4 grams.

Discussion

76.	10 moles of C6H12 reacted with 18 moles of O2, how many moles of CO2 will produce?(a) 3(b) 6(c) 9(d) 12The question was asked at a job interview.Question is from Stoichiometry Applications Terminology in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Right choice is (d) 12 Easy explanation: The BALANCED chemical REACTION is C6H12 + 9O2 -> 6CO2 + 3H2O, => O2 is the LIMITING reagent, => MOLES of CO2 = (18/9)*6 = 12.

Discussion

77.	5 moles of Al2O3 are reacted with 10 moles H2SO4, how many moles of Al2(SO4)3 will produce?(a) 3.33(b) 10(c) 30(d) 33.3I got this question during a job interview.The query is from Stoichiometry Applications Terminology in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct option is (a) 3.33 Explanation: The balanced chemical reaction is AL2O3 + 3H2SO4 -> AL2(SO4)3 + 3H2O, =>moles of Al2(SO4)3 = 10/3 = 3.33.

Discussion

78.	If 28 grams of N2 and 10 grams of H2 are reacted, how much NH3 will produce?(a) 17 grams(b) 34 grams(c) 51 grams(d) 54 gramsThis question was posed to me during an online interview.The origin of the question is Stoichiometry Applications Terminology in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct choice is (b) 34 grams Explanation: MOLES of N2 = 28/28 = 1, moles of H2 = 10/2 = 5, Reaction is N2 + 3H2 -> 2NH3, => N2 is limiting REAGENT, => moles of NH3 = 21 = 2, => weight of NH3 = 217 = 34 grams.

Discussion

79.	4 moles of CO and 2 moles of O2 are reacted, then what type of reactant O2 is?(a) Limiting reagent(b) Excess reagent(c) Can’t say(d) None of the mentionedI had been asked this question in unit test.My doubt is from Stoichiometry Applications Terminology topic in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The correct choice is (d) None of the mentioned The explanation is: The BALANCED CHEMICAL reaction is 2CO + O2 -> 2CO2, => If 4 MOLES of CO are reacting, 2 moles of O2 will REACT, this means none of the two is limiting reagent or excess reagent.

Discussion

80.	2 moles of N2 and 8 moles of H2 are reacted, then what type of reactant N2 is?(a) Limiting reagent(b) Excess reagent(c) Can’t say(d) None of the mentionedThis question was addressed to me during an interview for a job.This key question is from Stoichiometry Applications Terminology in portion The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The correct CHOICE is (a) Limiting reagent Explanation: The balanced chemical reaction is N2 + 3H2 -> 2NH3, => If 2 MOLES of N2 are REACTING only 6 moles of H2 will react, this MEANS H2 is an excess reagent and N2 is a limiting reagent.

Discussion

81.	4 moles of CH4 and 4 moles of O2 are reacted, then what type of reactant CH4 is?(a) Limiting reagent(b) Excess reagent(c) Can’t say(d) None of the mentionedI had been asked this question in a job interview.This is a very interesting question from Stoichiometry Applications Terminology topic in division The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The correct choice is (b) EXCESS REAGENT Explanation: The BALANCED chemical REACTION is CH4 + 2O2 -> CO2 + 2H2O, => If 4 moles of O2 are reacting only 2 moles of CH4 will react, this means CH4 is an excess reagent.

Discussion

82.	4FeS2 + 11O2 -> 2Fe2O3 + 8SO2, what is the extent of reaction if 512 grams of SO2 is produced?(a) 1(b) 2(c) 3(d) 4I got this question during an online exam.Origin of the question is Stoichiometry Applications Terminology topic in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The CORRECT option is (a) 1 The explanation: MOLES of SO2 = 512/64 = 8, => EXTENT of REACTION = (8 – 0)/8 = 1.

Discussion

83.	Which of the following is true about excess reagents?(a) Consumes completely(b) Consumes partially(c) Does not react(d) None of the mentionedI got this question in a national level competition.The above asked question is from Stoichiometry Applications Terminology topic in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The correct option is (b) Consumes partially The explanation: EXCESS reagents are REACTANTS which are excess in AMOUNT and REACTS partially in a reaction.

Discussion

84.	Which of the following is true about limiting reagents?(a) Consumes completely(b) Consumes partially(c) Does not react(d) None of the mentionedI got this question in examination.This interesting question is from Stoichiometry Applications Terminology topic in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The correct OPTION is (a) Consumes COMPLETELY The best EXPLANATION: Limiting reagent is the REACTANT which reacts completely in a reaction.

Discussion

85.	H2O2 + H2 -> 2H2O, if the extent of reaction is 10, how much water is produced?(a) 10 moles(b) 20 moles(c) 30 moles(d) 40 molesThe question was asked in final exam.Query is from Stoichiometry Applications Terminology topic in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Right option is (b) 20 MOLES To explain: 10 = (x – 0)/2, => x = 20 moles.

Discussion

86.	CH4 + 2O2 -> CO2 + 2H2O, what is the extent of reaction if only 50% of 96 grams of CH4 is consumed?(a) 1(b) 2(c) 3(d) 4I got this question in semester exam.Question is taken from Stoichiometry Applications Terminology in division The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Right choice is (C) 3 To EXPLAIN: MOLES of CH4 = 96/16 = 6, => Extent of reaction = (6*0.5 – 6)/(-1) = 3.

Discussion

87.	N2 + 2O2 -> 2NO2, what is the extent of reaction if 6 moles of NO2 is produced?(a) 3(b) 6(c) 12(d) 18The question was asked in an interview.Query is from Stoichiometry Applications Terminology topic in portion The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The correct answer is (a) 3 To explain I would say: EXTENT of REACTION = (6 – 0)/2 = 3.

Discussion

88.	What is extent of reaction of a in the reaction 2CO + O2 -> 2CO2, if 20 moles CO2 is produced?(a) 5(b) 10(c) 20(d) 40The question was posed to me in class test.My doubt is from Stoichiometry Applications Terminology in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The CORRECT answer is (B) 10 Easy explanation: EXTENT of reaction = (20 – 0)/2 = 10.

Discussion

89.	60 grams of FeS2, is burnt in air, how much sulfur dioxide will produce?(a) 16 grams(b) 32 grams(c) 64 grams(d) 128 gramsI got this question in class test.My doubt is from Stoichiometry in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The CORRECT ANSWER is (c) 64 grams To elaborate: The BALANCED chemical reaction is 4FeS2 + 11O2 -> 2FE2O3 + 8SO2, => amount of SO2 produced = (60/120)(8/4)64 = 64 grams.

Discussion

90.	xFeS2 + yO2 -> zFe2O3 + wSO2, what is the value of x + y + z + w?(a) 16(b) 21(c) 25(d) 32The question was asked in homework.The query is from Stoichiometry in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct option is (c) 25 The best EXPLANATION: The balanced chemical reaction is 4FeS2 + 11O2 -> 2Fe2O3 + 8SO2, => X + y + z + w = 25.

Discussion

91.	20 grams of NaOH is reacted with excess HCl, how much NaCl will it produce?(a) 29.25 grams(b) 58.5 grams(c) 117 grams(d) 234 gramsThe question was posed to me in homework.I would like to ask this question from Stoichiometry topic in division The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» CORRECT answer is (a) 29.25 grams For explanation I would say: The balanced chemical reaction is NAOH + HCL -> NaCl + H2O, => AMOUNT of NaCl = (20/40)*58.5 = 29.25 grams.

Discussion

92.	158 grams of potassium permanganate is reacted with ferrous sulfide in the presence of hydrochloric acid, approximately how much ferric sulfate will it produce?(a) 111 grams(b) 169 grams(c) 254 grams(d) 399 gramsI had been asked this question during an interview for a job.This is a very interesting question from Stoichiometry topic in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» RIGHT choice is (a) 111 GRAMS For explanation: The balanced chemical REACTION is 18KMnO4 + 10FeS + 32H2SO4 -> 18MnSO4 + 5Fe2(SO4)3 + 9K2SO4 + 32H2O, => WEIGHT of ferric sulfate = (158/158)(5/18)400 = 111.1 grams ≈ 111 grams.

Discussion

93.	xKMnO4 + yFeS + zH2SO4 -> xMnSO4 + wFe2(SO4)3 + uK2SO4 + zH2O, what is the value of x + y + z + w + u?(a) 60(b) 74(c) 85(d) 98The question was posed to me in examination.Question is from Stoichiometry topic in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Correct answer is (B) 74 To ELABORATE: The balanced CHEMICAL reaction is 18KMnO4 + 10FeS + 32H2SO4 -> 18MnSO4 + 5Fe2(SO4)3 + 9K2SO4 + 32H2O, => x + y + z + w + U = 74.

Discussion

94.	1 mole of glucose is burnt, how much carbon dioxide will it produce?(a) 44 grams(b) 176 grams(c) 264 grams(d) 352 gramsI got this question during an interview for a job.The question is from Stoichiometry in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» CORRECT answer is (b) 176 grams The explanation: The balanced chemical reaction is C6H12O6 + 6O2 -> 6CO2 + 6H2O, => moles of CO2 produced = 6, => AMOUNT of CO2 produced = 6*44 = 264 grams.

Discussion

95.	Pentane is burnt to produce carbon dioxide 40% of which can be converted into carbon monoxide, how much Butane must be burnt to produce 176 grams of carbon monoxide?(a) 18 grams(b) 36 grams(c) 72 grams(d) 96 gramsI have been asked this question in exam.I'm obligated to ask this question of Stoichiometry in division The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The correct choice is (b) 36 GRAMS Best explanation: The BALANCED chemical reaction is C5H12 + 8O2 -> 5CO2 + 6H2O, Let the mass of PENTANE be x, => (x/72)544*(40/100) = 176, => x = 36 grams.

Discussion

96.	78 grams of benzene is burnt in air, how much water will it produce?(a) 18 grams(b) 36 grams(c) 54 grams(d) 72 gramsThe question was posed to me during an online interview.I would like to ask this question from Stoichiometry in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» Right choice is (c) 54 grams To explain I WOULD say: The BALANCED CHEMICAL reaction is C6H6 + 7.5O2 -> 6CO2 + 3H2O, => MOLES of water = 378/78 = 3, => weight of water produced = 318 = 54 grams.

Discussion

97.	56 grams of carbon monoxide is oxidized with excess oxygen, how much carbon dioxide will it produce?(a) 22 grams(b) 44 grams(c) 66 grams(d) 88 gramsThe question was asked in examination.My question is taken from Stoichiometry topic in division The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» RIGHT choice is (d) 88 grams The explanation: The BALANCED chemical reaction is 2CO + O2 -> 2CO2, => moles of CO2 = moles of CO = 56/28 = 2, => amount of CO2 = 2*44 = 88 grams.

Discussion

98.	C5H12 + xO2 -> yCO2 + zH2O, what is the value of x + y*z?(a) 24(b) 38(c) 46(d) 54The question was posed to me in quiz.This intriguing question comes from Stoichiometry topic in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The correct answer is (b) 38 For EXPLANATION I would say: The balanced chemical reaction is: C5H12 + 8O2 -> 5CO2 + 6H2O, => X + yz = 8 + 56 = 38.

Discussion

99.	20 grams of CaCO3 is heated, how much calcium oxide will produce?(a) 5.6 grams(b) 11.2 grams(c) 22.4 grams(d) 44.8 gramsI had been asked this question during an online interview.Enquiry is from Stoichiometry topic in section The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» RIGHT choice is (b) 11.2 grams Explanation: The balance CHEMICAL reaction is CACO3 -> CaO + CO2, MOLES of CaO = moles of CaCO3 = 20/100 = 0.2, => amount of CaO = 0.2*56 = 11.6 grams.

Discussion

100.	wC3H6O3 + xO2 –> yCO2 + zH2O, what is the value of w + x + y + z?(a) 3(b) 6(c) 10(d) 14I had been asked this question in an internship interview.This intriguing question originated from Stoichiometry topic in chapter The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering
Answer» The CORRECT OPTION is (d) 14 To elaborate: The balanced chemical reaction is: C3H6O3 + 3O2 –> 3CO2 + 3H2O, => w + X + y + z = 14.

Discussion

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