Pulp & Paper Questions and Answers – Wet End Chemistry

«
»

This set of Pulp and Paper Multiple Choice Questions and Answers (MCQs) focuses on “Wet End Chemistry”.

1. Formation is clearly dependent on fiber _________ which makes it very crucial. They used a pilot plant machine to evaluate numerous factors on fiber _________
a) Biocides
b) Flocculation
c) Alum chemistry
d) Zeta potential
View Answer

Answer: b
Explanation: There’s relatively little information on fiber flocculation in the literature. Formation’s clearly dependent on fiber flocculation, which makes it very important. Single fundamental study with a good evaluation of the literature is the work of Jokinen and Ebeling. They utilized a pilot plant machine to evaluate numerous factors on fiber flocculation.
advertisement

2. Mechanical properties of fibers were much more crucial than chemical aspects of the slurry.
a) True
b) False
View Answer

Answer: a
Explanation: Mechanical properties of fibers were much more crucial than chemical aspects of the slurry. An example, temp. from 18- 35°C had no effect, nor did pH from 3.9 to 10.7.

3. _________ had an important effect although the value depends on the pulp consistency; under one set of typical commercial conditions, flocculation would change by 1.2 times.
a) Fillers
b) Zeta potential
c) Fiber length
d) Flocculation
View Answer

Answer: c
Explanation:Fiber length had an imp. effect although the magnitude depends on the pulp consistency; under one set of typical commercial conditions, flocculation would change by 1.2 times the relative change in fiber length.

4. A variety of _________ aids were tested, and anionic polyacrylamides (P.A.M.) of high molecular weight had the most pronounced effect, with 0.5 percent causing up to 65 percent decrement in flocculation.
a) Deflocculation
b) Flocculation
c) Zeta potential
d) Fillers
View Answer

Answer: a
Explanation: A variety of deflocculation aids were tested, and anionic polyacrylamides (P.A.M.) of high molecular weight had the most pronounced effect, with 0.5 percent value causing up to 65 percent value decrement in flocculation. Chemicals could not be utilized alone to increment flocculation above 5 percent.
advertisement

5. Alum’s not used in rosin and A.S.A. sizing, as a retention aid, and as a drainage aid.
a) True
b) False
View Answer

Answer: b
Explanation: The behaviour of alum in aqueous sol. is crucial to various aspects of wet end chemistry. Alum is utilized in rosin and A.S.A. sizing, as a retention aid, and as a drainage aid.

6. _________ is the central chemical in wet end chemistry and has gained much attention. There are various papers describing the behaviour of alum during papermaking process that generally contradict with each other.
a) Filler
b) Alum
c) Zeta potential
d) Flocculation
View Answer

Answer: b
Explanation: Alum’s the central chemical in wet end chemistry and has gained much attention. There are various papers describing the behaviour of alum during papermaking that generally contradict with each other.

7. This role of _________ in coordination chemistry in retention has been very clear for decades to textile chemists that describe the caustic action of alum in textile dyeing-the same thing that occurs with rosin sizing.
a) Alum
b) Filler
c) Zeta potential
d) Deflocculation
View Answer

Answer: a
Explanation: This role of alum coordination chemistry in retention has been very clear for decades to textile chemists that describe the caustic action of alum in textile dyeing. The same thing that occurs with rosin sizing. In the textile field mordan is a substance that fixes a dye to a material.
advertisement

8. Al ions in solution form polymers by sharing _________ groups.
a) Phenyl
b) Hydroxide
c) Halogen
d) Metallic
View Answer

Answer: b
Explanation: Al ions in sol. form polymers by sharing hydroxide groups. Two adjacent aluminum ions share 2 -OH groups to form the chain; these linkages are termed hydroxo linkages and are relatively non-polar linkages, unlike the polar linkages often shown that would be destroyed by H2O.

9. The _________ is a colloidal effect having to do with charge distributions upon the surface of the visible suspended particles.
a) Fillers
b) Alum
c) Zeta potential
d) Deflocculation
View Answer

Answer: c
Explanation: The zeta potential is a colloidal effect having to do with charge distributions on the surface of the visible suspended particles. The zeta potential’s the charge density on the surface of colloids and of suspended particles.

10. It varies from about -50 mV to + 50 mV. Retention’s often at a max. when the charge density is near 0. This is probably where the solubility is the least. What property’s mentioned here?
a) Deflocculation
b) Flocculation
c) Zeta potential
d) Alum
View Answer

Answer: c
Explanation: The zeta potential’s a colloidal effect in which charge distributions on the surface of the visible suspended particles. The zeta potential’s the charge density on the surface of colloids and of suspended particles.
advertisement

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

advertisement
advertisement
advertisement
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