Pulp and Paper Multiple Choice Questions on “Sulphite Liquor Calculation”.
1. The concentration of chemicals in sulfite pulping are noted on an SO2 basis.
a) True
b) False
Answer: a
Clarification: Sulfite pulping’s carried out b/w pH 1.5 and 5, depending on the counterion to sulfite (bisulfite) and the ratio of base to H2SO3. The pulp’s in contact with the pulping chemicals for 4 – 14 hours and at temperature ranging from 130 to 160 °Celcius.
2. All chemical sulfite methods use nearly 80% chemical (SO2 basis) on a dry wood basis.
a) True
b) False
Answer: b
Clarification: All chemical sulfite methods use nearly 20% chemical (SO2 basis) on a dry wood basis.
3. The various salts of _________ acid are of central importance to the various sulfite-based processes. The chemistry of _________ acid as a function of pH is very important.
a) Hydrochloric
b) Hydrogen fluoride
c) Hydrogen bromide
d) Sulphurous
Answer: d
Clarification: The chemistry of sulfurous acid as a function of pH is very imp. The titration curve of H2CO3, the first proton’s a moderately strong acid and titrates along with any strong acids present.
4. The _________ equation could not be utilized for this part of the titration curve since the H2CO3 ionizes appreciably, thereby reducing the conc. of H2CO3 and changing the ratio of acid to conjugate base significantly.
a) Kennedy
b) Henderson-Hasselbalch
c) Jhonty-Miller
d) Kraft-Hammer
Answer: b
Clarification: The Henderson-Hasselbalch eq. could not be utilized for this part of the titration curve since the H2CO3ionizes appreciably, there by reducing the conc. of H2CO3 and changing the ratio of acid to conjugate base significantly.
5. _________ is a moderately strong acid. It’ll react completely with any of the 5 common hydroxides utilized in sulfite cooking.
a) Sulphurous acid
b) Hydrochloric acid
c) Sulphuric acid
d) Nitric acid
Answer: a
Clarification: Sulfurous acid is a moderately strong acid. It will react completely with any of the 5 common hydroxides used in sulfite cooking. The form of the react. is independent of the base and occurs in 2 steps if enough base is present.
6. Derive the gravimetric factor for converting Ca(HSO3)2 to SO2.
a) 0.634g SO2
b) 1.254g SO2
c) 9.325g SO2
d) 40.456g SO2
Answer: a
Clarification: 1 mole of Ca(HSO3)2 gives two moles of SO2: Ca(HSO3)2 andrarr; 2SO2 + Ca(OH)2
Therefore
1g Ca(HSO3)2 x (2 mol SO2) / (1 mol Ca(HSO3)2) x (1 mol Ca(HSO3)2) / (202.21g Ca(HSO3)2) x (64.06 SO2) / (1 mol SO2) = 0.634g SO2
7. The various salts of _________are of central importance to the various sulfite-based processes. The chemistry of sulfurous acid as a function of pH is very imp.
a) Chlorine
b) Sulphur
c) Sulfurous acid
d) Calcium
Answer: c
Clarification:The various salts of H2SO3are of central importance to the various sulfite-based processes. The chemistry of sulfurous acid as a function of pH is very imp.
8. Fill in the blank.
MOH + H2SO3andrarr; __________+H2O
a) M2SO3
b) MHSO3
c) No react
d) SO4
Answer: b
Clarification: Sulfurous acid’s a moderately strong acid. It’ll react completely with any of the 5 common hydroxides used for sulfite cooking. The form of the reaction is independent of the base and occurs in 2 steps if enough base is there.
9. What is the name of the
MOH + MHO3andrarr; ______+H2O
a) M2SO3
b) MHSO3
c) No react
d) SO4
Answer: b
Clarification: Sulfurous acid’s a moderately strong acid. It’ll react completely with any of the 5 common hydroxides utilized in sulfite cooking. The form of the reaction is independent of the base and occurs in 2 steps if enough base is there.
10. The higher this ratio, the less _________ decrement is predicted when cooking to a specified kappa number
a) lignin content
b) pulpwood
c) groundwood
d) cellulose viscosity
Answer: d
Clarification: Ratio of H-factor to G-factor rates at various temperatures. The higher this ratio, the less cellulose viscosity decrement is predicted when cooking to a specified kappa number
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