95 + Interview Questions in Moles in Basic Chemical Engineering Page 1 InterviewSolution

1.	What is the molecular weight of a mixture that contains 25% CO2, 40% O2 and 35% N2?(a) 11.2 g(b) 22.4 g(c) 33.6 g(d) 44.8 gThe question was posed to me in unit test.The question is from Analyses of Multicomponent Solutions and Mixtures topic in section Moles, Density & Concentration of Basic Chemical Engineering
Answer» Correct CHOICE is (c) 33.6 g Easy explanation: Molecular weight = (2544 + 4032 + 35*28)/100 = 33.6 g.

Discussion

2.	1 mole of Carbon dioxide enters in a reactor at a rate of 0.25 kg/s and leaves it at the rate of 1 kg/s, what are the number of moles of carbon dioxide leaves the reactor?(a) 0.25(b) 0.5(c) 0.75(d) 1This question was addressed to me in an international level competition.Asked question is from Flow Rate topic in section Moles, Density & Concentration of Basic Chemical Engineering
Answer» The correct CHOICE is (a) 0.25 For explanation: APPLYING reaction equilibrium EQUATION, 10.25 = N1, => n = 0.25.

Discussion

3.	What is the molar concentration of a solution with 49 grams of H2SO4 in 0.5 liter solution?(a) 1 mole/liter(b) 2 mole/liter(c) 3 mole/liter(d) 4 mole/literThe question was asked during an interview.The above asked question is from Concentration topic in section Moles, Density & Concentration of Basic Chemical Engineering
Answer» The CORRECT option is (a) 1 mole/liter The BEST explanation: MOLAR concentration = (49/98)/0.5 = 1 mole/liter.

Discussion

4.	What is the molar concentration of a solution with 32 grams of SO2 in 0.5 liter solution?(a) 1 mole/liter(b) 2 mole/liter(c) 3 mole/liter(d) 4 mole/literI had been asked this question in an internship interview.Enquiry is from Concentration in portion Moles, Density & Concentration of Basic Chemical Engineering
Answer» Correct OPTION is (a) 1 mole/liter The BEST I can EXPLAIN: MOLAR concentration = (32/64)/0.5 = 1 mole/liter.

Discussion

5.	What is the molar concentration of a solution with 44 grams of CO2 in 0.5 liter solution?(a) 1 mole/liter(b) 2 mole/liter(c) 3 mole/liter(d) 4 mole/literI had been asked this question in an interview for internship.The origin of the question is Concentration topic in section Moles, Density & Concentration of Basic Chemical Engineering
Answer» The correct CHOICE is (b) 2 mole/liter To explain: MOLAR CONCENTRATION = (44/44)/0.5 = 2 mole/liter.

Discussion

6.	What is the molar concentration of a solution with 32 grams of CH4 in 1 liter solution?(a) 1 mole/liter(b) 2 mole/liter(c) 3 mole/liter(d) 4 mole/literThis question was addressed to me in my homework.Question is taken from Concentration topic in chapter Moles, Density & Concentration of Basic Chemical Engineering
Answer» The CORRECT answer is (b) 2 mole/liter Easiest EXPLANATION: Molar concentration = (32/16)/1 = 2 mole/liter.

Discussion

7.	What is the molar concentration of a solution with 40 gram of NaOH in 1 liter solution?(a) 1 mole/liter(b) 2 mole/liter(c) 3 mole/liter(d) 4 mole/literI have been asked this question by my college director while I was bunking the class.I'd like to ask this question from Concentration in chapter Moles, Density & Concentration of Basic Chemical Engineering
Answer» Right CHOICE is (a) 1 mole/liter To EXPLAIN: MOLAR concentration = (40/40)/1 = 1 mole/liter.

Discussion

8.	What is the molarity of the mixture of two solution, first solution 4 M and 10 liter and second solution 2 M and 40 liter?(a) 1.2 M(b) 2.4 M(c) 4.8 M(d) 9.2 MThis question was addressed to me in an interview for job.Question is from Concentration in section Moles, Density & Concentration of Basic Chemical Engineering
Answer» Correct choice is (B) 2.4 M For explanation I would SAY: Molarity of MIXTURE = (M1V1 + M2V2)/(V1 + V2) = (410 + 240)/ (10 + 40) = 2.4 M.

Discussion

9.	A solution with density 2 g/cm^3, concentration 1 molar and weight 500 grams, then what is the mass of HNO3 in the solution?(a) 63 grams(b) 126 grams(c) 189 grams(d) 252 gramsThe question was posed to me in an online quiz.This question is from Concentration in portion Moles, Density & Concentration of Basic Chemical Engineering
Answer» The correct CHOICE is (d) 252 GRAMS The EXPLANATION: Moles of HNO3 = 1/(500/2000) = 4, = > mass of HNO3 = 4*63 = 252 grams.

Discussion

10.	A solution with density 1 g/cm^3 has 98 grams of H2SO4 in 402 grams of water, what is the concentration of solution?(a) 1 molar(b) 2 molar(c) 3 molar(d) 4 molarThis question was posed to me during an internship interview.My question is taken from Concentration in section Moles, Density & Concentration of Basic Chemical Engineering
Answer» The correct choice is (b) 2 MOLAR The best I can EXPLAIN: Moles of H2SO4 = 98/98 = 1, => concentration of SOLUTION = 1/(500/1) = 2*10^-6 mole/cm^3 = 2 molar.

Discussion

11.	How much Sodium is there in a solution with 10 Kg of solvent (Density = 5 Kg/m^3) and concentration 4 molar?(a) 23 grams(b) 92 grams(c) 184 grams(d) 276 gramsThe question was asked in an interview.I'd like to ask this question from Concentration topic in division Moles, Density & Concentration of Basic Chemical Engineering
Answer» Right answer is (c) 184 grams The EXPLANATION is: Volume of SOLVENT = 10/5 = 2 m^3, => moles of sodium = 42 = 8 moles, => MASS of sodium = 823 = 184 grams.

Discussion

12.	A 5 molar solution is 27.75% CaCl2 by mass, what is the density of the solution?(a) 1 g/cm^3(b) 2 g/cm^3(c) 3 g/cm^3(d) 4 g/cm^3I have been asked this question in an international level competition.I'd like to ask this question from Concentration topic in chapter Moles, Density & Concentration of Basic Chemical Engineering
Answer» Correct option is (B) 2 g/cm^3 The EXPLANATION is: LET the mass of Solution be 100 grams, => moles of CaCl2 = 27.75/111 = 0.25, Density of solution = 5*(100/0.25) = 2000 kg/m^3 = 2 g/cm^3.

Discussion

13.	What is the concentration of a solution with 10 grams of calcium in 1000 m^3 of water?(a) 150 ppm(b) 250 ppm(c) 800 ppm(d) 1000 ppmThe question was posed to me in an online quiz.My query is from Concentration topic in division Moles, Density & Concentration of Basic Chemical Engineering
Answer» CORRECT answer is (b) 250 ppm The EXPLANATION is: MOLES of calcium = 10/40 =0.25, => concentration in ppm = (0.25/1000)*10^6 = 250 ppm.

Discussion

14.	What is the molarity of a solution with a mass of solute 10 kg mass and 100 liter volume?(a) 0.1 molar(b) 1 molar(c) 10 molar(d) 100 molarI got this question in exam.This interesting question is from Concentration topic in section Moles, Density & Concentration of Basic Chemical Engineering
Answer» CORRECT CHOICE is (a) 0.1 MOLAR For EXPLANATION: MOLARITY = 10/100 = 0.1 molar.

Discussion

15.	What is the concentration of a 22 grams of carbon dioxide occupying 0.5 m^3 volume?(a) 1 mole/m^3(b) 2 mole/m^3(c) 11 mole/m^3(d) 22 mole/m^3This question was addressed to me in final exam.I need to ask this question from Concentration topic in portion Moles, Density & Concentration of Basic Chemical Engineering
Answer» The CORRECT ANSWER is (a) 1 mole/m^3 To explain I would say: Moles of carbon DIOXIDE = 22/44 = 0.5, => concentration = 0.5/0.5 = 1 mole/m^3.

Discussion

16.	What is the concentration of 100 lbs. of solution occupying 25 m^3 of volume?(a) 1.8 Kg/m^3(b) 2.7 Kg/m^3(c) 4 Kg/m^3(d) 8 Kg/m^3This question was addressed to me in quiz.My question is taken from Concentration topic in portion Moles, Density & Concentration of Basic Chemical Engineering
Answer» The CORRECT ANSWER is (a) 1.8 Kg/m^3 For explanation I would SAY: MASS of SOLUTION = 100*0.453 = 45.3 kg, => Concentration of solution = 45.3/25 = 1.8 kg/m^3.

Discussion

17.	Which of the following is not the unit of concentration?(a) Mole/m^3(b) Molar(c) N/m^3(d) ppmThis question was posed to me in my homework.This interesting question is from Concentration topic in portion Moles, Density & Concentration of Basic Chemical Engineering
Answer» CORRECT ANSWER is (C) N/m^3 Best explanation: CONCENTRATION is MOLES per unit volume or mass per unit volume, so N/m^3 cannot be a unit of concentration.

Discussion

18.	A mixture contains 10% CO, 40% CO2 and 50% H2O, what is the mass percent of CO2?(a) 9.5(b) 15.4(c) 39.5(d) 74.1I have been asked this question in an international level competition.My question is based upon Analyses of Multicomponent Solutions and Mixtures topic in chapter Moles, Density & Concentration of Basic Chemical Engineering
Answer» CORRECT ANSWER is (a) 9.5 Best explanation: Mass PERCENT of CO2 = 1028/[1028 + 4044 + 5018] = 9.5%.

Discussion

19.	A mixture contains 20% NaCl, 30% CH4 and 50% H2O, what is the mass percent of NaCl?(a) 21(b) 34(c) 45(d) 68The question was posed to me by my college director while I was bunking the class.My doubt is from Analyses of Multicomponent Solutions and Mixtures in chapter Moles, Density & Concentration of Basic Chemical Engineering
Answer» Right answer is (B) 34 Best explanation: Mass percent of NaCl = 2035.5/[2035.5 + 3016 + 5018] = 34%.

Discussion

20.	A mixture contains 20% CO2, 30% SO2 and 50% H2O, what is the mass percent of CO2?(a) 23(b) 45(c) 66(d) 87I got this question during an interview.This interesting question is from Analyses of Multicomponent Solutions and Mixtures topic in chapter Moles, Density & Concentration of Basic Chemical Engineering
Answer» Correct answer is (a) 23 The BEST EXPLANATION: Let the moles be 20, 30 and 50, => MASS percent of CO2 = (2044)/[2044 + 3064 + 5018] = 23%.

Discussion

21.	The mole percent of CO2 and H2O in a mixture is 40% and 60% respectively, what is the mass percent of CO2?(a) 24.1(b) 47.2(c) 61.9(d) 78.5This question was posed to me in an online interview.My question is from Analyses of Multicomponent Solutions and Mixtures topic in section Moles, Density & Concentration of Basic Chemical Engineering
Answer» Correct ANSWER is (c) 61.9 The explanation: Let the moles be 40 and 60, => mass of CO2 = 40*44 = 1760, mass of H2O = 1080, => mass percent of CO2 = 61.9%.

Discussion

22.	The mole percent of H2 and N2 in a mixture is 50% each, what is the mass percentage of H2?(a) 12.5(b) 25(c) 50(d) 87.5I had been asked this question at a job interview.The above asked question is from Analyses of Multicomponent Solutions and Mixtures in division Moles, Density & Concentration of Basic Chemical Engineering
Answer» The correct choice is (a) 12.5 To explain I would say: Let the MOLES be 50 each, => Mass of H2 = 100, Mass of N2 = 700, => Mass PERCENTAGE of H2 = 100/(100 + 700)*100 = 12.5%.

Discussion

23.	A gaseous mixture composed of 20% CH4, 30% C2H4, 35% C2H2, and 15% C2H2O. What is the average molecular weight of the mixture?(a) 20(b) 25(c) 6.75(d) 9.25This question was addressed to me in class test.The doubt is from Analyses of Multicomponent Solutions and Mixtures topic in chapter Moles, Density & Concentration of Basic Chemical Engineering
Answer» RIGHT option is (c) 6.75 To elaborate: Since it is a GASEOUS mixture so the PERCENTAGES are by mole, => average molecular weight of mixture = {(20/100)16 + (30/100)28 + (35/100)26 + (15/100)42}/4 = 6.75.

Discussion

24.	A liquid mixture composed of 20% CH4, 30% C2H4, 35% C2H2, and 15% C2H2O. What is the average molecular weight of the mixture?(a) 20(b) 25(c) 6.75(d) 9.25This question was posed to me during an internship interview.This is a very interesting question from Analyses of Multicomponent Solutions and Mixtures in portion Moles, Density & Concentration of Basic Chemical Engineering
Answer» The CORRECT ANSWER is (b) 25 For explanation: Since it is a liquid mixture so the percentages are by WEIGHT, => average molecular weight of mixture = (20 + 30 + 35 + 15)/4 =25.

Discussion

25.	A gaseous mixture is composed of 20% CO2, 40% O2 and 40% N2. What is the mass fraction of N2?(a) 0.307(b) 0.416(c) 0.529(d) 0.784I got this question during an interview for a job.I would like to ask this question from Analyses of Multicomponent Solutions and Mixtures topic in chapter Moles, Density & Concentration of Basic Chemical Engineering
Answer» The correct OPTION is (a) 0.307 Best explanation: LET the total moles of the mixture be 100, => mass of CO2 = 2044 = 880 g, mass of ¬O2 = 4016 = 640 g, mass of N2 = 40*14 = 560 g, => mass fraction of N2 = 560/(880 + 640 + 560) = 0.307.

Discussion

26.	If hydrogen is 14% by weight in CH3(OH)x(NH3)y, then what is the possible value of x*y?(a) 6(b) 12(c) 18(d) 24This question was addressed to me by my college professor while I was bunking the class.This interesting question is from Analyses of Multicomponent Solutions and Mixtures topic in division Moles, Density & Concentration of Basic Chemical Engineering
Answer» The correct choice is (a) 6 To explain I would say: Let the weight of compound be 100 g, => weight of hydrogen = 14 g, => 3y + X + 3 = 14 => 3y + x = 11, => and 12 + 14 + 16x + 14y = 100, => 8X + 7y = 37, solving both equations we GET x = 2 and y = 3, => x*y = 6.

Discussion

27.	A liquid mixture of O2, CH4 and CO has the composition 32% O2, 16% CH4 and 52% CO, then what is the mole fraction of CH4?(a) 0.1(b) 0.2(c) 0.25(d) 0.5This question was posed to me in an online interview.My question comes from Analyses of Multicomponent Solutions and Mixtures in section Moles, Density & Concentration of Basic Chemical Engineering
Answer» Right answer is (b) 0.2 Explanation: LET the TOTAL weight of the mixture be 100 g, => weight of each component are 32 g, 16 g and 52 g respectively, => MOLES of O2 = 32/16 = 2, moles of CH4 = 16/16 = 1, moles of CO = 52/26 = 2 g, => mole fraction of CH4 = 1/5 = 0.2.

Discussion

28.	What is the value of x in C2H8(OH)x if the percentage by weight of hydrogen is 12%?(a) 1(b) 2(c) 3(d) 4The question was asked at a job interview.The query is from Analyses of Multicomponent Solutions and Mixtures topic in portion Moles, Density & Concentration of Basic Chemical Engineering
Answer» Correct CHOICE is (d) 4 For explanation I would say: Let the total weight of the compound be 100 g, => weight of hydrogen in the compound is 12 g, => X = 12 – 8 = 4.

Discussion

29.	A compound contain 12% of carbon, 16% of oxygen, 28% of nitrogen, 4% of hydrogen and 40% calcium by weight, then what can be the possible formula of the compound?(a) C2H3N2Ca(OH)(b) CH4N4Ca2(OH)(c) CH3N2Ca2(OH)(d) None of the mentionedI got this question in quiz.My query is from Analyses of Multicomponent Solutions and Mixtures in portion Moles, Density & Concentration of Basic Chemical Engineering
Answer» The CORRECT OPTION is (c) CH3N2Ca2(OH) Easy explanation: Ration of number of ATOMS, carbon: HYDROGEN: oxygen: nitrogen: calcium = 12/12: 4/1: 16/16: 28/14: 40/20 = 1:4:1:2:2.

Discussion

30.	If a compound contains 48% of Carbon, 48% of oxygen and 8% of hydrogen by weight, then what is the possible molecular formula of the compound?(a) C2H4O(b) CH4O3(c) C4H4O3(d) C4H8O3This question was posed to me in an interview for internship.Question is taken from Analyses of Multicomponent Solutions and Mixtures topic in division Moles, Density & Concentration of Basic Chemical Engineering
Answer» The correct CHOICE is (d) C4H8O3 The explanation: RATIO of number of atoms, CARBON: HYDROGEN: OXYGEN = 48/12: 8/1: 48/16 = 4:8:3.

Discussion

31.	What is the weight of 10 moles of a mixture with composition 15% O2, 25% SO2, 30% COCl2, 25% SO3 and 5% N2?(a) 124(b) 345(c) 507(d) 719I had been asked this question in my homework.Enquiry is from Analyses of Multicomponent Solutions and Mixtures in chapter Moles, Density & Concentration of Basic Chemical Engineering
Answer» Correct option is (d) 719 To explain I would say: Molecular weight of mixture = (1532 + 2564 + 3099 + 2580 + 528)/100 = 71.9, => Weight of mixture = 71.910 = 719.

Discussion

32.	A compound contains 40% of Sulphur and 60% of Oxygen, what is the empirical formula of the compound?(a) SO2(b) SO3(c) SO4(d) None of the mentionedI got this question in an interview.Enquiry is from Mole Fraction and Mass(Weight) Fraction topic in division Moles, Density & Concentration of Basic Chemical Engineering
Answer» The correct OPTION is (b) SO3 The best I can explain: Mole FRACTION of Sulphur = (40/32)[(40/32) + (60/16)] = 0.25, => Mole fraction of oxygen = 0.75, => Empirical formula of compound is SO3.

Discussion

33.	A mixture contains 80% of NaOH and 20% H2O by weight, what is the mole fraction of NaOH?(a) 0.24(b) 0.42(c) 0.64(d) 0.78This question was posed to me in exam.I want to ask this question from Mole Fraction and Mass(Weight) Fraction in portion Moles, Density & Concentration of Basic Chemical Engineering
Answer» RIGHT option is (C) 0.64 Best EXPLANATION: MOLE fraction of HCL = (80/40)[(80/40) + (20/18)] = 0.64.

Discussion

34.	A mixture contains 10 grams each of CH4, H2O, and SO2, what is the mole fraction of CH4?(a) 0.14(b) 0.31(c) 0.46(d) 0.67The question was asked by my school principal while I was bunking the class.Question is from Mole Fraction and Mass(Weight) Fraction topic in portion Moles, Density & Concentration of Basic Chemical Engineering
Answer» The correct choice is (c) 0.46 To ELABORATE: Mole FRACTION of CH4 = (10/16)/[(10/16) + (10/18) + (10/64)] = 0.46.

Discussion

35.	A mixture contains 80% of HCl and 20% H2O by weight, what is the mole fraction of HCl?(a) 0.15(b) 0.29(c) 0.45(d) 0.66The question was posed to me during an internship interview.Origin of the question is Mole Fraction and Mass(Weight) Fraction in division Moles, Density & Concentration of Basic Chemical Engineering
Answer» The CORRECT choice is (d) 0.66 The best I can EXPLAIN: MOLE fraction of HCL = (80/36.5)/[(80/36.5) + (20/18)] = 0.66.

Discussion

36.	A mixture contains 23 g of ethanol and 36 g of water, some acetic acid is added to the mixture and its mole fraction becomes 0.5, how much acetic acid was added?(a) 25 g(b) 75 g(c) 100 g(d) 150 gThe question was asked during an online exam.This intriguing question originated from Mole Fraction and Mass(Weight) Fraction topic in division Moles, Density & Concentration of Basic Chemical Engineering
Answer» RIGHT answer is (d) 150 g To explain I WOULD say: Let m grams of acetic ACID was added, => 0.5 = (m/60)/{(23/46) + (36/18) + (m/60)}, => m = 150 g.

Discussion

37.	A mixture contains 9 gram each of H2O and NaCl, what is the mole fraction of NaCl?(a) 0.15(b) 0.23(c) 0.45(d) 0.64This question was posed to me in semester exam.My question is from Mole Fraction and Mass(Weight) Fraction in chapter Moles, Density & Concentration of Basic Chemical Engineering
Answer» Correct ANSWER is (b) 0.23 The EXPLANATION: MOLE fraction of NaCl = (9/58.5)/[9/58.5 + 9/18] = 0.23.

Discussion

38.	A neutral gas that is made of nitrogen and hydrogen only contains 7 g of nitrogen is in a mixture of with total mass 17 g, what is the mass fraction of the gas?(a) 0.5(b) 0.25(c) 0.45(d) 0.8This question was addressed to me in examination.The above asked question is from Mole Fraction and Mass(Weight) Fraction topic in division Moles, Density & Concentration of Basic Chemical Engineering
Answer» Correct answer is (a) 0.5 The best explanation: The neutral gas that is made of nitrogen and HYDROGEN is NH3, => moles of nitrogen = moles of NH3 = 7/14 = 0.5, => mass of hydrogen = 1.5*1 = 1.5 G => TOTAL mass of NH3 = 7 + 1.5 = 8.5 g, => mass fraction = 8.5/17 = 0.5.

Discussion

39.	A mixture of gases SO2, O2 and 4 g of N2 and total mass of mixture is 10 g, what is the sum of mole fraction of SO2 and O2?(a) 0.25(b) 0.5(c) 0.75(d) 1I got this question during an interview.The query is from Mole Fraction and Mass(Weight) Fraction in division Moles, Density & Concentration of Basic Chemical Engineering
Answer» The correct CHOICE is (c) 0.75 For explanation I would say: Sum of the mole FRACTION of all GASES = 1, => sum of mole fraction of SO2 and O2 = 1 – 4/10 = 0.75.

Discussion

40.	If the mole fraction of SO2 in H2SO4 is 0.2, what is the ratio of mass of sulfur and oxygen in the solution?(a) 0.166(b) 6(c) 1.8(d) 0.555This question was addressed to me in class test.Question is from Mole Fraction and Mass(Weight) Fraction topic in portion Moles, Density & Concentration of Basic Chemical Engineering
Answer» The correct option is (d) 0.555 The best I can EXPLAIN: Let moles of SO2 and H2SO4 be x and y RESPECTIVELY, => x/(x + y) = 0.2, => y/x = 4, => ratio of MASS of sulfur and oxygen in SOLUTION = (x32 + y32)/ (x2(16) + y4(16)) = 0.555.

Discussion

41.	If the mole fraction of sodium is 0.25 in 9 moles of liquid carbon dioxide, what is the mass fraction of sodium?(a) 0.10(b) 0.15(c) 0.20(d) 0.25This question was addressed to me in an interview.My query is from Mole Fraction and Mass(Weight) Fraction in chapter Moles, Density & Concentration of Basic Chemical Engineering
Answer» Correct OPTION is (b) 0.15 The explanation: 0.25 = N/(n + 9), => n = 3, => MASS of sodium = 323/(323 + 9*44) = 0.15.

Discussion

42.	A solution has 25% w/w solution of Sodium Chloride in 10 grams of water what is the mole fraction of Sodium Chloride?(a) 0.05(b) 0.06(c) 0.07(d) 0.08I had been asked this question in an international level competition.The above asked question is from Mole Fraction and Mass(Weight) Fraction topic in division Moles, Density & Concentration of Basic Chemical Engineering
Answer» RIGHT answer is (C) 0.07 For explanation: Mass of sodium CHLORIDE = 10*25/100 = 2.5 GRAMS, => moles of sodium chloride = 2.5/58.5 = 0.0427, moles of water = 10/18 = 0.555, => mole fraction = 0.0427/(0.0427 + 0.555) = 0.07.

Discussion

43.	What is the mass fraction of 4 moles of Sodium in 8 moles of Hydrogen chloride?(a) 0.24(b) 0.48(c) 0.56(d) 0.72The question was posed to me during an online exam.I'm obligated to ask this question of Mole Fraction and Mass(Weight) Fraction topic in chapter Moles, Density & Concentration of Basic Chemical Engineering
Answer» CORRECT answer is (a) 0.24 For explanation I would SAY: Mass of sodium = 423 = 92 g, mass of hydrogen chloride = 836.5 = 292 g, => mass fraction of sodium = 92/(92 + 292) = 0.24.

Discussion

44.	If the mole fraction of 4.5 moles of solute is 0.5, what is the number of moles of solvent?(a) 9(b) 4.5(c) 1.5(d) 3This question was addressed to me during an interview.Question is taken from Mole Fraction and Mass(Weight) Fraction in chapter Moles, Density & Concentration of Basic Chemical Engineering
Answer» CORRECT ANSWER is (B) 4.5 The BEST explanation: 0.5 = 4.5/(4.5 + N), => n = 4.5.

Discussion

45.	What is the mole fraction of sodium with moles n in a solution with moles of solvent N?(a) N/n(b) n/N(c) n/(n + N)(d) N/(n + N)This question was addressed to me in homework.I need to ask this question from Mole Fraction and Mass(Weight) Fraction in portion Moles, Density & Concentration of Basic Chemical Engineering
Answer» Correct option is (C) N/(n + N) Best explanation: Mole fraction is the ratio of moles of solvent and the total number of moles of solution, => mole fraction = n/(n + N).

Discussion

46.	What is the unit of mole fraction?(a) Kg/m^3(b) N/m^3(c) m^-2(d) None of the mentionedI have been asked this question in an internship interview.The doubt is from Mole Fraction and Mass(Weight) Fraction in division Moles, Density & Concentration of Basic Chemical Engineering
Answer» RIGHT choice is (d) None of the mentioned The explanation is: Since the mole FRACTION is ratio of the moles of solute and the moles of SOLUTION, it has no UNIT.

Discussion

47.	24 grams of CH4 is passed in the process in 3 minutes, what is the molar flow rate?(a) 0.1 mole/min(b) 0.3 mole/min(c) 0.5 mole/min(d) 0.7 mole/minI have been asked this question in class test.My question comes from Flow Rate topic in chapter Moles, Density & Concentration of Basic Chemical Engineering
Answer» The correct option is (C) 0.5 mole/min The explanation is: FLOW rate of FLUID = (24/16)/3 = 0.5 mole/min.

Discussion

48.	16 grams of oxygen is passed in the process in 5 minutes, what is the molar flow rate?(a) 0.1 mole/min(b) 1 mole/min(c) 10 mole/min(d) 16 mole/minI got this question in quiz.Question is taken from Flow Rate in section Moles, Density & Concentration of Basic Chemical Engineering
Answer» Correct CHOICE is (a) 0.1 mole/min To EXPLAIN: Flow rate of FLUID = (16/32)/5 = 0.1 mole/min.

Discussion

49.	20 Kg/s of a fluid with density 5 Kg/m^3 is passed into a tank of capacity 60 m^3, how much time will it take to fill the tank?(a) 5 Second(b) 10 Second(c) 15 Second(d) 20 SecondThe question was posed to me in unit test.I want to ask this question from Flow Rate topic in section Moles, Density & Concentration of Basic Chemical Engineering
Answer» Correct OPTION is (c) 15 SECOND The explanation: FLOW rate of fluid = 20/5 = 4 m^3/s, => TIME = 60/4 = 15 second.

Discussion

50.	15 Kg/s of a fluid with density 5 Kg/m^3 is passed into a tank of capacity 30 m^3, how much time will it take to fill the tank?(a) 3 Second(b) 10 Second(c) 30 Second(d) 100 SecondI had been asked this question in an internship interview.This is a very interesting question from Flow Rate topic in division Moles, Density & Concentration of Basic Chemical Engineering
Answer» Right choice is (B) 10 Second To explain I WOULD say: Flow rate of fluid = 15/5 = 3 m^3/s, => Time = 30/3 = 10 second.

Discussion

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What is the concentration of a solution with 10 grams of calcium in 1000 m^3 of water?(a) 150 ppm(b) 250 ppm(c) 800 ppm(d) 1000 ppmThe question was posed to me in an online quiz.My query is from Concentration topic in division Moles, Density & Concentration of Basic Chemical Engineering

What is the molarity of a solution with a mass of solute 10 kg mass and 100 liter volume?(a) 0.1 molar(b) 1 molar(c) 10 molar(d) 100 molarI got this question in exam.This interesting question is from Concentration topic in section Moles, Density & Concentration of Basic Chemical Engineering

What is the concentration of 100 lbs. of solution occupying 25 m^3 of volume?(a) 1.8 Kg/m^3(b) 2.7 Kg/m^3(c) 4 Kg/m^3(d) 8 Kg/m^3This question was addressed to me in quiz.My question is taken from Concentration topic in portion Moles, Density & Concentration of Basic Chemical Engineering

Which of the following is not the unit of concentration?(a) Mole/m^3(b) Molar(c) N/m^3(d) ppmThis question was posed to me in my homework.This interesting question is from Concentration topic in portion Moles, Density & Concentration of Basic Chemical Engineering

What is the value of x in C2H8(OH)x if the percentage by weight of hydrogen is 12%?(a) 1(b) 2(c) 3(d) 4The question was asked at a job interview.The query is from Analyses of Multicomponent Solutions and Mixtures topic in portion Moles, Density & Concentration of Basic Chemical Engineering

A mixture contains 9 gram each of H2O and NaCl, what is the mole fraction of NaCl?(a) 0.15(b) 0.23(c) 0.45(d) 0.64This question was posed to me in semester exam.My question is from Mole Fraction and Mass(Weight) Fraction in chapter Moles, Density & Concentration of Basic Chemical Engineering

What is the unit of mole fraction?(a) Kg/m^3(b) N/m^3(c) m^-2(d) None of the mentionedI have been asked this question in an internship interview.The doubt is from Mole Fraction and Mass(Weight) Fraction in division Moles, Density & Concentration of Basic Chemical Engineering

16 grams of oxygen is passed in the process in 5 minutes, what is the molar flow rate?(a) 0.1 mole/min(b) 1 mole/min(c) 10 mole/min(d) 16 mole/minI got this question in quiz.Question is taken from Flow Rate in section Moles, Density & Concentration of Basic Chemical Engineering