chemistry 1

1.

1 point

galvanizing process the temperature of sulphuric acid bath used to remove impurities should be

d) 130 to 150c

c) 100 to 120c

b) 60 to 90c

a) 40 to 50c

2.

1 point

galvanization process to avoid oxidation of molten zinc the flux used is

a) Ammonium chloride

c) Barium sulphate

d) Calcium chloride

b) Ammonium hydroxide

3.

1 point

3) Which of following causes corrosion of iron

a) Oxygen

b) Hydrogen

a) Oxygend) Moisture & Oxygen.

c) Strong base

4.

1 point

29) In the wet theory of corrosion

a) Dry cell is formed

c) Galvanic cell is formed

b) Fuel cell is formed

d) None of these

5.

1 point

55) Tin coated utensil are used foodstuff because

c) Tin is not reactive

a) Tin is more reactive

b) Tin is less reactive

d) None of these

6.

1 point

54) In tinning process the flux used is

a) Zinc chloride

d) Ammonia

c) Calcium chloride

b) Ammonium chloride

7.

1 point

48) The temperature molten zinc in galvanizing process is

b) 440 to 500c

a) 300 to 350c

d) 600 to 700c.

c) 425 to 430c

8.

1 point

pitting corrosion, the part of metal underneath the impurity becomes

a) Catholic

d) None of these

b) Inert

c) Anodic

9.

1 point

53) In tinning process the less reactive metal used is

d) Tin

a) Zinc

b) Aluminum

c) Iron

10.

1 point

16) Electrochemical corrosion is also called as

a) Immersed corrosion

b) Wet corrosion

c) Atmospheric corrosion

d) Both A & B

11.

1 point

30) During oxygen concentration type corrosion, the corrosion

uniform throughout

d) Occur at cathodic part

a) Occurs at more oxygenated part

b) Occurs at led oxygenated part

12.

1 point

51) Galvanized ware cannot be used for storing foodstuff because

c) Zinc is not reactive

d) None of these

a) Zinc is more reactive

b) Zinc is less reactive

13.

1 point

8) Which metal forms stable porous oxide film

c) Active metal

b) Alkali & alkaline metal earth

a) Inert metal

d) None of these

14.

1 point

66) Anodic coating protect underlying metal

d) Due to low reduction potential

b) Due to noble character

a) Due to higher oxidation potential

c) Due to higher reduction potential

15.

1 point

6) Dry corrosion is also called as

c) Electrochemical corrosion

a) Chemical corrosion

d) Both A & B

b) Atmospheric corrosion

16.

1 point

12) Which oxide film is protective

b) Stable non porous oxide film

a) Stable porous oxide film

d) All the above.

c) Volatile oxide film

17.

1 point

56) Foodstuff container should not be

d) Galvanized

a) Electroplated

c) Tinned

b) Gladded

18.

1 point

5) Atmospheric corrosion is also called as.

b) Wet corrosion

a) Direct chemical corrosion

c) Immersed corrosion

d) Waterline corrosion.

19.

1 point

61) One of the common sacrificial anodic metal is

a) Iron

c) Copper

b) Magnesium

d) Titanium

20.

1 point

11) The metal Al,Sn,Cu & Pb forms which oxide film

c) Unstable oxide film

d) None of these

a) Volatile oxide film

b) Stable non porous oxide film

21.

1 point

31) In differential aeration corrosion, the more oxygenated part acr as

b) Cathode

c) Both a & b

d) None of these

a) Anode

22.

1 point

galvanizing process the iron sheet to galvanized is first cleaned by pickling with the dilute solution of

c) Hydrochloric acid

b) Sulphuric acid.

d) Potassium chloride

a) Nitric acid

23.

1 point

73) In phosphate coating the electrolyte used is

c) Both A & B

a) Phosphoric acid

b) Phosphate

d) None of these

24.

1 point

45) The method to prevent corrosion of iron by zinc coating is called is

a) Galvanization

b) Electrolysis

c) Cathodic protection

d) Anode protection

25.

1 point

Anodizing coating are generally produced on which metal and alloy

a) Inert

c) Ferrous

b) Non ferrous

26.

1 point

25) During wet corrosion

a) Anodic part undergoes oxidation

c) Anodic part undergoes reduction

b) Cathodic part undergoes oxidation

d) None of these

27.

1 point

21) In hydrogen evolution type of electrochemical corrosion mechanism hydrogen gas evolves at

a) Anode

c) Electrolyte

d) None of these

b) Cathode

28.

1 point

15) Molybdenum oxide forms which oxide film

c) Unstable oxide film

a) Non porous oxide film

b) Porous oxide film

d) Volatile oxide film

29.

1 point

7) Which of the following metal forms stable non porous oxide film

d) calcium.

a) Sodium

c) Potassium

b) Aluminum

30.

1 point

9) Which of the following metal forms unstable oxide film

b) Aluminum

c) Calcium

a) Gold

d) Sodium.

31.

1 point

37) Name the material which decreases waterline corrosion

a) Greases

c) Antifouling paints

d) Graphite

b) Waxes

32.

1 point

1) The corrosion of metal brought about by the direct chemical action of environment of atmospheric gasses is called………………..

a) Chemical corrosion

Pitting corrosion

Waterline corrosion

Electrochemical corrosion

33.

1 point

59) Sacrificial anodic protection method is also called as

a) Anodic protection

b) Galvanic protection

d) All the above

c) Metal coating

34.

1 point

69) Anodizing coating is carried by ……….process

c) Both A & B

a) Cathodic reduction

d) None of these

b) Anodic oxidation.

35.

1 point

27) The rate of corrosion of iron I atmosphere depend upon

a) The humidity of atmosphere

d) All the above factors

c) The frequency of rain fall

b) The degree of pollution of te atmospheric air

36.

1 point

52) The method to prevent corrosion of iron by tin coating is called

a) Galvanization

b) Cementation

d) Cladding

c) Tinning

37.

1 point

44) With decrease in ph value the rate of corrosion

(1) Decreasesa) Decrease

Remain constant

) None of these.

Increase

38.

1 point

17) Wet corrosion is also called as

d) Oxidation corrosion

c) Chemical corrosion

a) Electrochemical corrosion

b) Atmospheric corrosion

39.

1 point

galvanizing process the temperature of annealing chamber is

c) 650c

a) 100c

d) 950c

b) 250c

40.

1 point

1) Any process of destruction of solid metallic material through chemical or electrochemical attack by its environmental is called………………

a) Reduction

Corrosion

b) Protection

d) Erosion.