12th class (Fsc) Chemistry unit 6 MCQs
26. Cast iron contains:
a. 0.25-2.5% C
b. 2.5-4.5%C
c. 0.12-0.25% C
d. None of these
27. wrought iron contains:
a. 0.25-2.5% C
b. 0.12-0.25% C
c. 2.5-4.5% C
d. None of these
28. Steel contains:
a. 0.25-2.5% C
b. 2.5-4.5% C
c. 0.12-0.25% C
d. None of these
29. As percentage of C increase in the iron, hardness:
a. Increases
b. Decreases
c. Can not be predicted
d. Remains the same
30. Satinless steel contains Fe and:
a. AI
b. Cu
c. Ag
d. Cr
31. How much molten pig or cast iron from the blast furnace is def into Bessemer’s converter?
a. 25 to 30 tons
b. 10 to 15 tons
c. 30 to 35 tons
d. 20 to 25 tons
32. Which one of the slag is used as fertilizer?
a. CaSO3
b. CaSiO3
c. FeSiO3
d. Ca3 (PO4)2
33. The percentage of carbon in mild steel is:
a. 0.3 to 0.4 %
b. 0.05 to 0.1%
c. 0.2 to 0.3 %
d. 0.1 to 0.2 %
34. In Bessemer’s process, steel can ba prepared by using:
a. Steel scrap
b. Cast iron
c. Any one of the given
d. Wrought iron
35. Which type of lining is used in open-hearth furance when impurities like Mn, Si ec are present in iron used?
a. Amphoteric
b. Acidic
c. Neutral
d. Basic
36. What type of lining is used in open-hearth when impurities like P and s are present in iron used?
a. Acidic
b. Amphoteric
c. Neutral
d. Basic
37. Bronze is an alloy of Cu and:
a. Sb
b. Zn
c. Sn
d. As
38. Bassemer converter us used for the manufacture of:
a. Cast iron
b. Steel
c. Pig iron
d. Pe2O3
39. Indicate the composition of rust;
a. Fe2 O3 +FeCOH3
b. Fe2 O3 +Fe(OH)3
c. None of these
d. Fe2 O3 +Fe(OH)2
40. Which of the following catalysis the rusting:
a. O2-
b. H+
c. OH–
d. None of these
41. Rusting of iron in molar air involves:
a. Gain of electron by iron
b. Loss of electrons by iron
c. Hydration of iron
d. None of these
42. A common example of corrosion is:
a. Digestion of food
b. Burning of paper
c. Melting of ice
d. Rusting of iron
43. A common example of an alloy of iron is:
a. Stainless steel
b. Brass
c. German silver
d. Bronze
44. The process of covering of iron sheets with a layer of Zn is called;
a. Galvanizing
b. Annealing
c. Zn plating
d. Tempering
45. The coordination number in monochloro, mononitro, tetra amine paltinum suplhate is:
a. 8
b. 2
c. 6
d. 4
46. Gr2O3+4KOH → 2K2CrO4+KCL+2H2O in this reaction;
a. Cr is oxidized and CI is reduced
b. Cr is reduced
c. CI is reduced and O is oxidized
d. CI is oxidized
47. The formula of chromic anhydride is:
a. Cr2O4
b. CrO2
c. Cr2O5
d. Cr2O3
48. The chemical formula of mineral pyrolusite is:
a. Mn2O5
b. MnO2
c. Mn2O7
d. Mn2O3
49. The color of almost all chromates are:
a. Blue
b. Green
c. White
d. Yellow
50. Which one of the following is used in the preparation of yellow crown?
a. PcCrO4
b. Pb3O4
c. K2Cr2O7
d. KMnO4