Pulp & Paper Questions and Answers – Measurement of Lignin Content

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This set of Pulp and Paper Interview Questions and Answers for freshers focuses on “Measurement of Lignin Content”.

1. The measurement of lignin in chemical pulps is a vital tool to monitor the degree of cook (extent of delignification during pulping).
a) True
b) False
View Answer

Answer: a
Explanation: The measurement of lignin in chemical pulps is a vital tool to monitor the degree of cook (extent of delignification during pulping) to measure residual lignin before bleaching and the between various stages of bleaching to monitor the process.
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2. To measure residual lignin prior to bleaching pulp brightness between bleaching stages are often used to control the bleaching operation.
a) True
b) False
View Answer

Answer: a
Explanation: To calculate residual lignin prior to bleaching pulp brightness between bleaching stages are often used to control the bleaching operation.

3. Lignin is easily measured indirectly by measuring the amount of __________ consumed by lignin in a sample of pulp of known mass.
a) Anti oxidant
b) Oxidant
c) Pulp
d) Poison
View Answer

Answer: b
Explanation: Lignin is easily measured indirectly by measuring the amount of oxidant (such as Cl ) consumed by lignin in a sample of pulp of known mass.

4. The __________ test is an indirect method for determining amount of lignin consumption of permanganate ion.
a) Alfa
b) Beta
c) Gama
d) Kappa
View Answer

Answer: d
Explanation: The Kappa test is an indirect method used for determination. The kappa number is the number of milliliters of 0.1 KMn04 consumed by one gram of pulp in 0.5N sulftiric acid after a ten minute reaction time at 25°C under conditions such that one-half remains unreacted.
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5. __________ lignin is considered to be the same as the actual lignin content. __________ % = 0.15 x kappa number.
a) Alander
b) Palenius
c) Kyrklund
d) Klason
View Answer

Answer: d
Explanation: Klason lignin is considered to be the same as the actual lignin content. Alander, Palenius, and Kyrklund give the following relationship for sulfite and kraft chemical hardwood pulps: Klason lignin, % = 0.15 x kappa number.

6. A 40 ml K no. of 10 corresponds to a kappa no. of 14.5, 20 corresponds to 30.4 kappa number, and 30 corresponds to __________ kappa number.
a) 64.1
b) 32.1
c) 85.1
d) 95.1
View Answer

Answer: a
Explanation: log (kappa no.) = 0.837+ 0.0323 (40 ml K no.)

7. The __________ is a measurement of lignin content by the number of grams of gaseous Cl2 consumed by 100 grams dry pulp at 25 °C in 15 minutes.
a) Row number
b) Roe number
c) Chloe number
d) Christ number
View Answer

Answer: b
Explanation: The Roe number’s a measurement of lignin content by the number of grams of gaseous Cl2 consumed by 100 grams dry pulp at 25 °C (77 °F) in 15 minutes.
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8. The __________ is a test method just like that of Roe, except the CIO2 is generated in sit by acidification of sodium hypochlorite.
a) Klason lignin
b) Kappa number
c) Chlorine number
d) Roe number
View Answer

Answer: c
Explanation: The chlorine number is a test method just like that of Roe, except the CIO2 is generated in sit by acidification of sodium hypochlorite.

9. Chlorine number = __________ x Roe number.
a) 0.10
b) 0.20
c) 0.80
d) 0.90
View Answer

Answer: d
Explanation: The chlorine number is a test method, the CIO2 is generated in sit by acidification of sodium hypochlorite. Chlorine number = 0.90 x Roe number.

10. __________ lignin is the residue extracted after the total acid hydrolysis of carbohydrate portion of wood. It’s a gravimetric method for determining lignin directly in woody materials.
a) Klason
b) Karlson
c) Klux
d) Kurl
View Answer

Answer: a
Explanation: Klason lignin is the residue extracted after the total acid hydrolysis of carbohydrate portion of wood. It is a gravimetric method for determining lignin directly in woody materials.

Sanfoundry Global Education & Learning Series – Pulp and Paper.
To practice all areas of Pulp and Paper for Interviews, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer & SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage, Advanced C Programming, SAN Storage Technologies, SCSI Internals & Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him @ LinkedIn