12th class (Fsc) Chemistry unit 15 MCQs
26. Which fertilizer has maximum percentage of nitrogen:
a. Ammonium nitrate
b. Ammonia
c. Urea
d. Potassium nitrate
27. Phosphatic fertilizers increase the capacity of plants:
a. To accelerate fruit formation
b. Stimulate early growth
c. To resist diseases
d. All of these
28. Potassium fertilizers increase the capacity of plants:
a. To resist disease
b. To undergo photosynthesis
c. To produce protein
d. None of these
29. The potassium present in plant, helps the plant to:
a. Ripen the seeds and fruits
b. Increase the resistant against diseases
c. From starch,sugar and fibrous materials
d. All of these
30. The ration of lime stone and clay it.wet process for the manyfacture of cement is:
a. 2:1
b. 1:1
c. 3:1
d. 1:2
31. In the cooling zone for the manufacturing of cement. the temperature is:
a. 200-250oC
b. 50-100oC
c. 250-130oC
d. 150-200oC
32. Which one of the following raw materials is not present in the cement:
a. Blast furnace slag
b. Limestone
c. Redhead
d. Gypsum
33. Which is not a calcareous material?
a. Zymase
b. Lime
c. Lipase
d. Clay
34. Which substance is added to the air cooled cement clinker?
a. Alumina
b. Clay
c. Lipase
d. Gypsum
35. In wet process grinding is done in presence of:
a. NaOH
b. Steam
c. Water
d. All
36. Hydrate tricalcium aluminate react with gypsum to form:
a. Calcium hydroide
b. Tricalcium silicate
c. Calcium sulphoaluminate
d. Aluminium hydroxide
37. During setting of cement which compound form needle shaped cnstals:
a. Calcium hydroxide
b. Aluminum hydroxide
c. Tricalcium silicate
d. Tricalcium aluminate
38. Which combination was first used as cement by Joseph aspding
a. Limestone and sand
b. Clay and sand
c. Soap stone and clay
d. Lime stone and caly
39. The number of zones through which the charge passe’s in a-rotary kiln during manufacture of cement:
a. 4
b. 2
c. 5
d. 3
40. What is the main function of rotary kiln>
a. Drying of slurry
b. Heating lime stone
c. Preparation of clinker
d. Heating of clinker
41. Which is not a cataroius material?
a. Marble
b. Lime stone
c. Marine shll
d. Clay
42. Which squence of steps is correct for the manufacture of cement:
a. Crushing, mixing, heating, grinding
b. Mixing, heating, grinding, crushing
c. Crushing, grinding, mixin
d. crushing, heating, mixing, grinding
43. In NSSC which compound is used as cooking liqour:
a. Sodium hypochlorite
b. Sodium sulphite
c. Hydrogen peroxide
d. Potassium sulphite
44. pH in digester is maintaibned at:
a. 7-8
b. 4-5
c. 7-9
d. 6-7
45. Which of the following process is alkaline:
a. Craft process
b. Neutral sulphite semi chemical process
c. Sulphite process
d. None of these
46. Which of the following makes paper brittle:
a. Dust particles
b. Lignin
c. Lump of clay
d. Sand particles
47. Which of the following paper bleaching agents is largely used in Pakistan:
a. O3
b. CI2
c. CIO2
d. O2
48. Which one of the following is not common domesticv materials which are recycle it:
a. Iron
b. Paper
c. Glass
d. Plastics
49. The first paper was prepared by using Bark of them tree:
a. Bamboo
b. Mulberry tree
c. Raspberrt tree
d. Pineapple
50. Which substance is used as a filler or additive in paper making:
a. Lime
b. Cellulose
c. Gypsum salt
d. Starch