MCQOPTIONS
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MCQOPTIONS
This section includes 15 Mcqs, each offering curated multiple-choice questions to sharpen your Pulp Paper knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Pine and fir are difficult to brighten. Colour reduction occurs by altering __________ groups, the pulp is sometimes subsequently treated with SO2 to neutralize OH– and reduce any residual peroxide. |
| A. | Chromosome |
| B. | Chromophoric |
| C. | Dithionite |
| D. | Peroxide |
| Answer» C. Dithionite | |
| 2. |
__________ with sodium hydroxide and/or sodium peroxide is utilized to produce the high pH that is crucial to produce the active perhydroxyl ion, HOO–. |
| A. | Hydrogen dioxide |
| B. | Hydrogen peroxide |
| C. | Hydrogen silicate |
| D. | Hydrogen fluoride |
| Answer» D. Hydrogen fluoride | |
| 3. |
__________ (5% on wood) is used usually after the addition of magnesium ion. The mechanism for inactivating the ions by __________ precipitating the ions, but, strictly speaking, it is not a chelating agent. |
| A. | Sodium disulfate |
| B. | Sodium peroxide |
| C. | Sodium silicate |
| D. | is used usually after the addition of magnesium ion. The mechanism for inactivating the ions by __________ precipitating the ions, but, strictly speaking, it is not a chelating agent.a) Sodium disulfateb) Sodium peroxidec) Sodium silicated) Sodium hydroxide |
| Answer» D. is used usually after the addition of magnesium ion. The mechanism for inactivating the ions by __________ precipitating the ions, but, strictly speaking, it is not a chelating agent.a) Sodium disulfateb) Sodium peroxidec) Sodium silicated) Sodium hydroxide | |
| 4. |
Chelating agents, such as __________ have the added gain of preventing pulp dis-coloration by binding together with ferric ion that could otherwise form a colored complex with the phenolic lignin structure. |
| A. | Pulp |
| B. | Lignin |
| C. | Oxygen |
| D. | EDTA |
| Answer» E. | |
| 5. |
In hydrosufite bleching Zn+2SO2andrarr; __________ |
| A. | ZnSO |
| B. | Zn S2O4 |
| C. | Zn2SO4 |
| D. | ZnS2O4 |
| Answer» C. Zn2SO4 | |
| 6. |
___________WITH_SODIUM_HYDROXIDE_AND/OR_SODIUM_PEROXIDE_IS_UTILIZED_TO_PRODUCE_THE_HIGH_PH_THAT_IS_CRUCIAL_TO_PRODUCE_THE_ACTIVE_PERHYDROXYL_ION,_HOO‚ÄÖ√Ñ√∂‚ÀÖ√Ë‚ÀÖ¬®.?$# |
| A. | Hydrogen dioxide |
| B. | Hydrogen peroxide |
| C. | Hydrogen silicate |
| D. | Hydrogen fluoride |
| Answer» D. Hydrogen fluoride | |
| 7. |
Pine_and_fir_are_difficult_to_brighten._Colour_reduction_occurs_by_altering____________groups,_the_pulp_is_sometimes_subsequently_treated_with_SO2_to_neutralize_OH–_and_reduce_any_residual_peroxide.$# |
| A. | Chromosome |
| B. | Chromophoric |
| C. | Dithionite |
| D. | Peroxide |
| Answer» C. Dithionite | |
| 8. |
__________ (5% on wood) is used usually after the addition of magnesium ion. The mechanism for inactivating the ions by __________ precipitating the ions, but, strictly speaking, it is not a chelating agent? |
| A. | Sodium disulfate |
| B. | Sodium peroxide |
| C. | Sodium silicate |
| D. | Sodium hydroxide |
| Answer» D. Sodium hydroxide | |
| 9. |
Chelating agents, such as __________ have the added gain of preventing pulp dis-coloration by binding together with ferric ion that could otherwise form a colored complex with the phenolic lignin structure. |
| A. | Pulp |
| B. | Lignin |
| C. | Oxygen |
| D. | EDTA |
| Answer» E. | |
| 10. |
In hydrosufite bleching Zn+2SO2andrarr; __________ |
| A. | ZnSO<sub></sub> |
| B. | Zn S<sub>2</sub>O<sub>4</sub> |
| C. | Zn<sub>2</sub>SO<sub>4</sub> |
| D. | ZnS<sub>2</sub>O<sub>4</sub> |
| Answer» C. Zn<sub>2</sub>SO<sub>4</sub> | |
| 11. |
__________ (a common name in the industry, but dithionite is the preferred name) bleaching process is carried out with 0.5-1.0% dithionite on the wood. |
| A. | Hydroslufite |
| B. | Groundwood |
| C. | Kraft |
| D. | Sulphite |
| Answer» B. Groundwood | |
| 12. |
Brightened mechanical pulps are the ones subjected to colour reversion. Since the lignin is largely decoloured, but not removed, there is only a small loss of yield. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 13. |
Brightening of mechanical pulps is done by reducing agents like __________ |
| A. | Groundwood |
| B. | Sulphite |
| C. | Dithionite |
| D. | Dissolving pulp |
| Answer» D. Dissolving pulp | |
| 14. |
Mechanical pulps are bleached with chemicals just to alter many of the chromophores. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 15. |
__________ are most, sometimes conjugated double bond systems arising in the lignin of pulps. |
| A. | Chromosomes |
| B. | Chromophores |
| C. | Chloroplasts |
| D. | Chrome |
| Answer» C. Chloroplasts | |