1. Hardwood fibers are longer than that of softwood fibers.
a) True
b) False
Discussion
Explanation: The given statement is false. Softwood Hardwood fibers are longer than that of hardwood fibers. Compared to hardwoods, softwoods have fibers that are generally up to 2.5 times longer. As a result, hardwoods produce a finer, smoother but less strong sheet.
2. Hardwood has more amount of cellulose and hemicellulose present in it.
a) True
b) False
Discussion
Explanation: The given statement is true. Hardwood has more amount of cellulose and hemicellulose present in it. Hardwood has about 45% cellulose and 30% hemicellulose, whereas, softwood has about 42% cellulose and 27% hemicellulose.
3.________ expresses the lignin content of pulp.
a) Beta number
b) Gamma number
c) Kappa number
d) Alpha number
Discussion
Explanation: Kappa number expresses the lignin content of pulp. A high kappa number indicates a high lignin content. The kappa number of bleachable softwood and hardwood pulps is 30–40 and 18–20 respectively.
4. When was the first authentic paper made?
a) 250 AD
b) 100 AD
c) 105 AD
d) 500 AD
Discussion
Explanation: The first authentic papermaking, which is the formation of a cohesive sheet from the rebonding of separated fibers, has been attributed to Ts’ai-Lun of China in 105 AD, who used bamboo, mulberry bark and rags.
5. The principal hemicelluloses is glucomannon in hardwoods.
a) True
b) False
Discussion
Explanation: The given statement is false. The principal hemicelluloses are xylan in hardwoods and glucomannon in softwoods.
6. ________ has no fiber forming properties.
a) Lignin
b) Cellulose
c) Hemicellulose
d) Glucose
Discussion
Explanation: Lignin has no fiber-forming properties. This is the natural binding constituent of the cells of wood and plant stalks. It is a highly branched, three-dimensional (3D), alkylaromatic, thermoplastic polymer of uncertain size, built up largely from substituted phenylpropane or propylbenzene units.
7. _____ is lower MW mixed-sugar polysaccharides.
a) Lignin
b) Cellulose
c) Hemicellulose
d) Glucose
Discussion
Explanation: Hemicellulose is lower MW mixed-sugar polysaccharides, consisting of one or more of the following molecules: xylose, mannose, arabinose, galactose and uronic acids, with the composition differing from species to species.
8. ________ mainly determines the paper properties.
a) Lignin
b) Cellulose
c) Hemicellulose
d) Glucose
Discussion
Explanation: Hemicellulose mainly determines the paper properties. Hemicelluloses are largely responsible for hydration and development of bonding during beating of chemical pulps.
9. ______ is the natural binding constituent of the cells of wood and plant stalks.
a) Lignin
b) Cellulose
c) Hemicellulose
d) Glucose
Discussion
Explanation: Lignin is the natural binding constituent of the cells of wood and plant stalks. It is a highly branched, three-dimensional (3D), alkylaromatic, thermoplastic polymer of uncertain size, built up largely from substituted phenylpropane or propylbenzene units. Hydroxyl or methoxyl groups are attached to the benzene carbon atoms.
10. _______ softens at 160°C.
a) Pectin
b) Hemicellulose
c) Cellulose
d) Lignin
Discussion
Explanation: Lignin softens at 160°C. It is because of its densely branched structure. Also, it doesn’t have fiber forming properties adhering to the same reason.