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101.

What is the average molecular weight of a gas containing 20% N2 (molecular wt. = 28) and 80% SO2 (molecular wt. = 64)?(a) 28.4(b) 56.8(c) 24.4(d) 48.8I have been asked this question in an interview for job.The above asked question is from Mole and Molecular Weight-III in division Introductory Concepts of Chemical Process Calculation

Answer»

The correct choice is (B) 56.8

To EXPLAIN: Take 1 gm mole of the Gas and then average MOLECULAR weight = 0.20×28+0.80×64.

102.

What is the concentration of 36 grams of water occupying 1 m3 volume?(a) 1 mole / m3(b) 2 mole / m3(c) 11 mole / m3(d) 22 mole / m3The question was posed to me by my school principal while I was bunking the class.My question is based upon Concentration-I in section Introductory Concepts of Chemical Process Calculation

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The correct OPTION is (b) 2 mole / m3

The best I can explain: MOLES of water= 36/18 = 2, Concentration = 2/1= 1 mole / m3.

103.

A student has two solution of a substance. Solution-1: 25M, 400mL and Solution-2: 30M, 300M. What is the molarity of the final solutions if these two solutions are mixed?(a) 27.14(b) 22.14(c) 14.22(d) 14.27This question was addressed to me at a job interview.This intriguing question comes from Concentration-I in chapter Introductory Concepts of Chemical Process Calculation

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The CORRECT answer is (a) 27.14

Best EXPLANATION: M = (M1V1 + M2V2 )/(V1 + V2).

104.

Flow rate of the material in kg/min.(a) 0.262(b) 0.252(c) 0.242(d) 0.232I had been asked this question in an internship interview.Enquiry is from Density and specific gravity-II topic in chapter Introductory Concepts of Chemical Process Calculation

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The correct choice is (a) 0.262

The BEST explanation: Take 1 min. basis and then using molecular WEIGHT of material, flow rate and percentage of material, CALCULATE flow rate.

105.

The specific weight is also known as ________(a) Specific density(b) Specific volume(c) Weight density(d) None of the mentionedThe question was posed to me in class test.My question comes from Density and specific gravity-II topic in division Introductory Concepts of Chemical Process Calculation

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The CORRECT answer is (C) Weight density

For EXPLANATION: The specific weight is also KNOWN as weight density.

106.

What is the mass fraction of O in the sample?(a) 0.2(b) 0.4(c) 0.6(d) 0.8I have been asked this question in my homework.I would like to ask this question from Choosing a Basis topic in section Introductory Concepts of Chemical Process Calculation

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The correct answer is (b) 0.4

The best I can EXPLAIN: TAKE basis as 1 Kg MOLE of NA, MASS fraction = 16/40.

107.

What is the composition of the O2 gas on an SO2-free basis?(a) 0.78 and 0.22(b) 0.22 and 0.78(c) 0.70 and 0.25(d) 0.25 and 0.78This question was addressed to me in homework.My question comes from Choosing a Basis topic in chapter Introductory Concepts of Chemical Process Calculation

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The CORRECT option is (a) 0.78 and 0.22

To elaborate: First take a basis of 100 mole and then we GET the moles of each GAS. NEXT step is to eliminate 5 moles of SO2 and then CALCULATE the composition of the gas.

108.

25 psia is equal to(a) 25.88 in Hg(b) 50.88 in Hg(c) 75.88 in Hg(d) 100.88 in HgI got this question in an interview for internship.This intriguing question originated from Pressure and Hydrostatic Head-III in portion Introductory Concepts of Chemical Process Calculation

Answer» CORRECT CHOICE is (B) 50.88 in Hg

Easy explanation: 25 psia = (25*29.92)/14.7 = 50.88 Hg.
109.

The smallest temperature is(a) 25 degree Celsius(b) 250 degree Fahrenheit(c) 560 degree Rankine(d) 400 KelvinI had been asked this question during a job interview.This intriguing question comes from Temperature in division Introductory Concepts of Chemical Process Calculation

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The CORRECT ANSWER is (d) 400 Kelvin

Easiest EXPLANATION: ∆˚C = 1.8 ∆˚F and ∆˚K = 1.8∆˚F.

110.

What is the density of the liquid in kg/m3?(a) 2.39×10^3(b) 2.39(c) 2.39×10^2(d) None of the mentionedThis question was addressed to me during an interview.Question is taken from Density and specific gravity-I topic in section Introductory Concepts of Chemical Process Calculation

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Correct option is (a) 2.39×10^3

To EXPLAIN: Specific gravity is the RATIO of the DENSITY of a substance to the density of a reference MATERIAL.

111.

What is the mole fraction of Ar?(a) 0.2(b) 0.4(c) 0.6(d) 0.8I had been asked this question during a job interview.I'm obligated to ask this question of Mole and Molecular Weight topic in section Introductory Concepts of Chemical Process Calculation

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Correct CHOICE is (a) 0.2

Easiest explanation: MOLE fraction = Moles of the COMPONENT / Total moles.

112.

What is the weight percentage of C2H4?(a) 41.17(b) 51.17(c) 61.17(d) 71.17I had been asked this question in class test.This intriguing question comes from Mole and Molecular Weight in section Introductory Concepts of Chemical Process Calculation

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The CORRECT CHOICE is (a) 41.17

Easy EXPLANATION: Weight PERCENTAGE = Weight of the component / Total weight.

113.

What is mole percentage of C3H8?(a) 0.2(b) 0.4(c) 0.6(d) 0.8This question was posed to me during an interview for a job.My question is taken from Mole and Molecular Weight topic in portion Introductory Concepts of Chemical Process Calculation

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The CORRECT CHOICE is (a) 0.2

Easy EXPLANATION: Mole percentage = MOLES of the component / Total moles.

114.

What is the mole fraction of N2?(a) 0.2(b) 0.4(c) 0.6(d) 0.8This question was addressed to me during an internship interview.This question is from Mole and Molecular Weight topic in chapter Introductory Concepts of Chemical Process Calculation

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The CORRECT option is (b) 0.4

To explain I would SAY: MOLE fraction = Moles of the component / TOTAL moles.

115.

How many moles of O2 are there in the cylinder?(a) 1(b) 2(c) 4(d) 6I had been asked this question during an interview.My doubt is from Mole and Molecular Weight topic in chapter Introductory Concepts of Chemical Process Calculation

Answer» CORRECT choice is (B) 2

Easy explanation: Number of MOLES = mass / MOLECULAR WEIGHT.
116.

What is mole percentage of H2SO4?(a) 10.4(b) 20.4(c) 30.4(d) 40.4I had been asked this question by my school teacher while I was bunking the class.I'd like to ask this question from Mole and Molecular Weight-IV in chapter Introductory Concepts of Chemical Process Calculation

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Right option is (c) 30.4

Explanation: MOLE PERCENTAGE = MOLES of the component / Total moles.

117.

Flow rate can be expressed as?(a) Kg/s(b) Litres/s(c) Moles/s(d) All of the mentionedI had been asked this question during an internship interview.My question comes from Flow Rate in section Introductory Concepts of Chemical Process Calculation

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The correct CHOICE is (d) All of the mentioned

To ELABORATE: All a, b, C are the units of FLOW rate.

118.

The velocity of water in a pipe of area 10 m2 is 5 m/s, what will be the flow rate of water?(a) 25 m3 / s(b) 50 m3 / s(c) 75 m3 / s(d) 100 m3 / sI had been asked this question during an online interview.The above asked question is from Flow Rate topic in division Introductory Concepts of Chemical Process Calculation

Answer» RIGHT choice is (b) 50 m3 / s

To explain I WOULD say: FLOW rate = Area*Velocity = 5*10 = 50 m3/s.
119.

Pressure at a point in the liquid is(a) Same in all directions(b) Greater in the upward direction(c) Grater in the downward direction(d) None of the mentionedI had been asked this question during a job interview.This intriguing question comes from Pressure and Hydrostatic Head-II in chapter Introductory Concepts of Chemical Process Calculation

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Right answer is (c) Grater in the DOWNWARD direction

Explanation: PRESSURE IDS proportional to the depth.

120.

A force opposite to the force required to support a mass in gravitational field is(a) Pressure(b) Weight(c) Gravitational acceleration(d) None of the mentionedI had been asked this question during an online exam.My question is based upon Pressure and Hydrostatic Head-II in chapter Introductory Concepts of Chemical Process Calculation

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Correct answer is (b) Weight

Easy EXPLANATION: A force opposite to the force REQUIRED to support a MASS in GRAVITATIONAL field is weight.

121.

What is mass of the solute that is present in 50 mL of a 0.15 mol/L solution of NaCl?(a) 0.22(b) 0.44(c) 0.66(d) 0.88This question was addressed to me in an internship interview.Origin of the question is Concentration-II topic in division Introductory Concepts of Chemical Process Calculation

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Correct CHOICE is (b) 0.44

Best explanation: CONCENTRATION = MOLES / VOLUME.

122.

A 1000 ml solution has 0.25 gms of solute. What is the concentration(gm/L)?(a) 0.25(b) 2.5(c) 25(d) 250This question was addressed to me in a job interview.My enquiry is from Concentration-II topic in division Introductory Concepts of Chemical Process Calculation

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The CORRECT CHOICE is (a) 0.25

To elaborate: CONCENTRATION = Mass / VOLUME.

123.

How many moles of Ne are there in the cylinder?(a) 1(b) 2(c) 4(d) 6The question was posed to me at a job interview.The doubt is from Mole and Molecular Weight topic in chapter Introductory Concepts of Chemical Process Calculation

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Correct option is (B) 2

Explanation: NUMBER of MOLES = mass / molecular WEIGHT.

124.

Relative molecular mass of CO2 is _________(a) 22(b) 44(c) 66(d) 88This question was addressed to me in final exam.Query is from Mole and Molecular Weight-V in section Introductory Concepts of Chemical Process Calculation

Answer» RIGHT ANSWER is (B) 44

The BEST explanation: Relative molecular mass = Molecular mass of C + 2(Molecular mass of Oxygen).
125.

What are the number moles of Oxygen present there in the bucket?(a) 14.82(b) 13.82(c) 12.82(d) 11.82The question was posed to me in quiz.My question is based upon Mole and Molecular Weight-IV in chapter Introductory Concepts of Chemical Process Calculation

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Correct OPTION is (d) 11.82

The BEST explanation: MOLES of OXYGEN = Moles of NaOH + Moles of H2O + 4(Moles of H2SO4).

126.

How many gm moles oxygen are there in 88 gms carbon di oxide?(a) 1(b) 2(c) 3(d) 4This question was posed to me in an online quiz.Question is from Mole and Molecular Weight-III in division Introductory Concepts of Chemical Process Calculation

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The CORRECT option is (d) 4

Easiest explanation: 88gms of CO2 = 2 MOLES of CO2 = 4 moles of oxygen.

127.

How many molecules are there in 4*10^-3 lb moles of carbon?(a) 12.044 *10^23(b) 12.044 *10^26(c) 12.044 *10^29(d) 12.044 *10^22This question was posed to me during an interview.My question is from Mole and Molecular Weight-II in division Introductory Concepts of Chemical Process Calculation

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The correct CHOICE is (a) 12.044 *10^23

For explanation: 4*10^-3 LB MOLES of C = 2 gm moles of C.

128.

A pseudo molecular weight computed by dividing the mass in a mixture or solution by the number of moles in the mixture or solution is called(a) Molecular weight(b) Average molecular weight(c) Atomic weight(d) None of the mentionedI have been asked this question during an online interview.My doubt is from Mole and Molecular Weight-II in section Introductory Concepts of Chemical Process Calculation

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Right answer is (b) Average molecular WEIGHT

For explanation: A pseudo molecular weight computed by dividing the MASS in a mixture or solution by the NUMBER of moles in the mixture or solution is CALLED average molecular weight.

129.

The __________ of an element is the mass of an atom based on the scale that assigns a mass of exactly 12 to the carbon isotope 12C .(a) Molecular weight(b) Average molecular weight(c) Atomic weight(d) None of the mentionedI have been asked this question in quiz.My question is from Mole and Molecular Weight-II topic in portion Introductory Concepts of Chemical Process Calculation

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The CORRECT option is (c) Atomic weight

The EXPLANATION: The atomic weight of an element is the MASS of an atom based on the scale that assigns a mass of EXACTLY 12 to the carbon isotope 12C.

130.

Mass of a compound per mole is _________(a) Mole(b) Molecular weight(c) Mole fraction(d) None of the mentionedI got this question in an interview for job.This intriguing question originated from Mole and Molecular Weight-II in chapter Introductory Concepts of Chemical Process Calculation

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Right option is (b) Molecular weight

To EXPLAIN I WOULD say: Mass of a compound per MOLE is CALLED Molecular weight.

131.

How many pounds of NaOH are in 15 g mole of NaOH?(a) 1.32(b) 2.64(c) 3.96(d) 5.28The question was posed to me in a job interview.Enquiry is from Mole and Molecular Weight-II topic in division Introductory Concepts of Chemical Process Calculation

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The CORRECT choice is (a) 1.32

To ELABORATE: FIRST convert 15 g mole of NaOH to grams of NaOH, and then USE the conversion of 1 lb = 454g.

132.

How much gram mole of H2SO4 is there in the vessel?(a) 18.53(b) 0.0408(c) 18.53(d) None of the mentionedThis question was addressed to me during an interview.This intriguing question comes from Mole and Molecular Weight-II in chapter Introductory Concepts of Chemical Process Calculation

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Correct OPTION is (a) 18.53

Easy explanation: LB mole = MASS in lb/molecular weight.

133.

58.5 gms of NaCl contains(a) 1 gm mole of NaCl(b) 1 lb mole of NaCl(c) Both a and b(d) Neither a nor bThis question was posed to me in class test.My doubt stems from Mole and Molecular Weight-I topic in portion Introductory Concepts of Chemical Process Calculation

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Correct CHOICE is (a) 1 GM mole of NaCl

For explanation: gm moles = mass in gm/molecular WEIGHT.

134.

How many gram moles of N2 does it contain?(a) 8107(b) 6789(c) 7583(d) 7357This question was posed to me in final exam.This intriguing question comes from Mole and Molecular Weight-I topic in division Introductory Concepts of Chemical Process Calculation

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Right ANSWER is (a) 8107

The explanation is: gm MOLES = mass in gm/molecular WEIGHT.

135.

How many lb moles of O are there in 22 g of H2SO4?(a) 1.978*10^-4(b) 1.978*10^-3(c) 1.978*10^-2(d) 1.978*10^-1I have been asked this question in an interview.My query is from Mole and Molecular Weight-I in portion Introductory Concepts of Chemical Process Calculation

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Right CHOICE is (b) 1.978*10^-3

The BEST I can explain: lb mole = 454*gm mole, lb moles of O = 4(lb moles of H2SO4).

136.

How many g moles of S are there in 22 g of H2SO4?(a) 0.4489(b) 0.2245(c) 0.1256(d) 0.3256I got this question in homework.This intriguing question originated from Mole and Molecular Weight-I topic in portion Introductory Concepts of Chemical Process Calculation

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The CORRECT option is (b) 0.2245

To explain: g MOLES of S = gm moles of H2SO4.

137.

Two statements are given as below  I: lb mole is composed of 453.6*6.022*1023 moleculesII: gm mole is composed of 6.022*1023 moleculesNumber of correct statements is/are(a) 0(b) 1(c) 2(d) None of the mentionedI have been asked this question by my school teacher while I was bunking the class.This question is from Mole and Molecular Weight-I in section Introductory Concepts of Chemical Process Calculation

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The CORRECT ANSWER is (c) 2

The explanation is: A gm mole is COMPOSED of 6.022*10^23 molecules and 1 LB mole is 453.6 times a gm mole.

138.

How many g moles of H are there in 22 g of H2SO4?(a) 0.4489(b) 0.2245(c) 0.1256(d) 0.3256This question was posed to me in an interview.My doubt is from Mole and Molecular Weight-I topic in division Introductory Concepts of Chemical Process Calculation

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The CORRECT OPTION is (a) 0.4489

For explanation: g MOLES of H= 2(gm moles of H2SO4).

139.

Molecular weight is the ratio of _______ and ________(a) Mass, Mole(b) Mole, Mass(c) Mole, Mole(d) Mass, MassI had been asked this question in an international level competition.This key question is from Mole and Molecular Weight-I topic in division Introductory Concepts of Chemical Process Calculation

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Correct CHOICE is (a) MASS, Mole

Easiest EXPLANATION: MOLECULAR WEIGHT is the ratio of Mass and Mole.

140.

Amount of substance containing 6.022*10^23 entities is called(a) Mole(b) Molecular weight(c) Molar mass(d) None of the mentionedThe question was asked in unit test.This interesting question is from Mole and Molecular Weight-I in section Introductory Concepts of Chemical Process Calculation

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The correct CHOICE is (a) MOLE

The EXPLANATION: Amount of substance containing 6.022*10^23 entities is CALLED mole.

141.

Using the proper number of significant figures 6 X 6 equals to(a) 3(b) 4(c) 36(d) 40I had been asked this question in homework.My doubt stems from Signifiant Figures in division Introductory Concepts of Chemical Process Calculation

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Correct choice is (d) 40

Explanation: Significant FIGURE in 40 is only ONE that is same as 6.

142.

How many significant numbers are there in 420?(a) 1(b) 2(c) 3(d) 0This question was posed to me in exam.My question comes from Signifiant Figures topic in section Introductory Concepts of Chemical Process Calculation

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The CORRECT option is (b) 2

To EXPLAIN I would SAY: ZERO does not count in significant number here.

143.

0.009046879855, round off the number to three significant figures(a) 0.0905(b) 0.0904(c) 0.09046(d) 0.09035This question was posed to me by my college director while I was bunking the class.Enquiry is from Signifiant Figures in chapter Introductory Concepts of Chemical Process Calculation

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The CORRECT answer is (a) 0.0905

To elaborate: In such SITUATION we ROUND up the last digit from 4 up to 5.

144.

Correctly rounded, the product 3.000 cm × 30.0 cm is(a) 9.0 x 10^1 cm^2(b) 9.000 x 10^1 cm^2(c) 9 x 10^1 cm^2(d) 9.00 x 10^1 cm^2I have been asked this question in class test.Question is taken from Signifiant Figures topic in chapter Introductory Concepts of Chemical Process Calculation

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Correct choice is (d) 9.00 x 10^1 cm^2

For explanation: The measurement with the LEAST NUMBER of significant DIGITS DETERMINES the number of significant digits in the quotient.

145.

Correctly rounded, the quotient 5.000 g / 50.0 mL is(a) 0.10 g/mL(b) 0.1 g/mL(c) 0.100 g/mL(d) 0.1000 g/mLThis question was posed to me during an interview for a job.My doubt stems from Signifiant Figures in division Introductory Concepts of Chemical Process Calculation

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Correct OPTION is (C) 0.100 g/mL

Explanation: The measurement with the LEAST NUMBER of significant DIGITS determines the number of significant digits in the quotient.

146.

The theoretical production rate of a chemical is 1µg/(mL)(min.). What is the actual production rate of the chemical in lb mol/ (day)(ft3) with an efficiency of 98%?(a) 0.0880(b) 0.0800(c) 0.0449(d) 0.529I had been asked this question during a job interview.This interesting question is from Signifiant Figures topic in section Introductory Concepts of Chemical Process Calculation

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The CORRECT option is (a) 0.0880

Easy EXPLANATION: 1 LB mole = 454 g mole and 1 L = 3.531×10-2 FT3.

147.

The given numbers are shown with their significant figures respectively. Find out the wrong one option?(a) 26.24 and 4(b) 24000. and 5(c) 0.000460 and 3(d) 28000.0 and 5I got this question in a job interview.My query is from Signifiant Figures in portion Introductory Concepts of Chemical Process Calculation

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Correct ANSWER is (d) 28000.0 and 5

Best EXPLANATION: ZERO after a decimal point counts in SIGNIFICANT figure.

148.

Standard form of 2145.67 is(a) 2.14*10^3(b) 2.14567*10^3(c) 0.214*10^4(d) None of the mentionedI got this question during an interview for a job.I'd like to ask this question from Signifiant Figures in chapter Introductory Concepts of Chemical Process Calculation

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The CORRECT CHOICE is (B) 2.14567*10^3

To ELABORATE: 21456.7 = 2.14567*10^3.

149.

What is the unit of A?(a) atm(b) K(c) 1/atm(d) 1/KThe question was asked in class test.My doubt stems from Dimensional Consistency topic in section Introductory Concepts of Chemical Process Calculation

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The CORRECT ANSWER is (a) atm

The EXPLANATION: The UNIT of A is same as the unit of PRESSURE.

150.

Find out the dimensionless quantity(a) Pressure(b) Reynolds number(c) Viscosity(d) DensityThis question was posed to me in class test.The doubt is from Dimensional Consistency in chapter Introductory Concepts of Chemical Process Calculation

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Right answer is (b) REYNOLDS number

The best I can EXPLAIN: Reynolds number has no dimension or UNITS.