Εικόνες σελίδας
PDF
Ηλεκτρ. έκδοση

CHAPTER XXXI.

IRON. Fe 56.

1. FIND the mass of a cylindrical cast-iron (A 7.25) cannon-bolt, 10 c.m. in diameter and 15 c.m. long.

2. Find the mass of a cast-iron (A 7·25) hexagonal cannon-bolt, each side of the hexagon being 2 c.m. and its length 20 c.m. (The area of a hexagon is 2.598 times the

square of a side.)

3. An empty spherical Mallet shell (A 7·25) is a yard in diameter and two inches thick. Find its mass in kilograms.

4. A wrought-iron (▲ 7·8) cube weighs 1 kilogram, find the length of its edge in centimetres.

5. Find the mass of a cast-iron (▲ 7·25) grape-shot 2 c.m. in diameter.

6. How many grams does a cubic foot of pure iron (A 7.88) weigh more than a cubic foot of steel (▲ 7·75) ?

7. Find the mass in tons of a forged steel cylinder (A 7·8) 13 metres long and a metre in diameter.

8. The best Low Moor iron will bear a pull of 64 200 lbs. per square inch, how many kilos. will a wire 2 m.m. in diameter carry?

L. C. A.

14

9. On January 18th 1881 the barometer in London stood at 30.961 inches. How many m.m. high was it?

10. An iron (▲ 7·8) armour plate is 12 feet long, 4 feet wide and 6 inches thick, find its mass in tons.

11. What volume of hydrogen at 15° C. and 730 m.m. is required to reduce 273 grams of ferric oxide?

[blocks in formation]

12. How much ferrous oxide can be made by heating 147 grams of ferrous oxalate in hydrogen?

13.

FeC20,2H,O=2H ̧O + CO2 + CO + FeO,

2

What volume of hydrogen is evolved during the formation of 463 grams of crystallized ferrous chloride?

Fe + 2HCl + 4H2O = FeCl ̧ . 4H2O+H ̧.

2

14. What volume of hydrogen at 13° C. is required to reduce 894 grams of ferric oxide ?

[blocks in formation]

15. Find the percentage composition of potassium ferrate (K,FeO).

16. How many tons of coke containing 97 per cent. of carbon are required to reduce 388 tons of hematite?

Fe2O2+3C = 3CO + 2Fe.

17. Find the percentage composition of ferrous oxalate (FeC ̧ ̧.2H2O).

4

18. Find the percentage composition of hydrated ferrous carbonate (FeCO ̧ . H2O).

19. How many cubic metres of carbon monoxide at 1200° C. are evolved in making a ton of iron from ferrous carbonate?

FeCO2+2C = 3CO + Fe.

20. How much colcothar and Nordhausen sulphuric acid can be made from 348 tons of green vitriol ?

6FeSO. 7H2O + 30 = 39H ̧0+ Fe ̧O2+ 2Fe ̧3SO. 3H ̧0.

2

2

2 3

[ocr errors][subsumed][subsumed][subsumed][subsumed][subsumed]

21. What volume of oxygen is required to burn 10 grams of iron?

3Fe +40 FeO.

22. Find the formula of a salt containing iron 28 per cent., sulphur 24 per cent. and oxygen 48 per cent.

23. Crystallized ferric and ammonium sulphate contains of its mass of iron, find its formula.

24. How many grams does a cubic foot of iron (▲ 7·7) weigh?

25.

What is the percentage of iron and of sulphur in iron pyrites (FeS2)?

26. What volume of oxygen is required to convert 100 grams of ferrous into ferric oxide ?

2FeO + 0 = Fe ̧ ̧.

27. Calculate the percentage composition of the carbides of iron (a) Fe C, (ß) Fe¿C.

28. Calculate the percentage composition of crystallized ferrous sulphate (FeSO. 7H,O).

29. How many grams of ferrous sulphide are required to give 750 c.c. of hydrogen sulphide ?

FeS + 2HCl = FeCl ̧ + H ̧S.

30. How much crystallized ferrous sulphate can be made from 10 grams of iron?

Fe + H2SO + 7H ̧0 = H ̧+ FeSO ̧ . 7H2O.

4

31. An iron (▲ 7·7)

wire 1 m.m. in diameter is burnt in a cylinder of oxygen. After the combustion the water rises in the cylinder through a height equal to the length of wire burnt. Find the radius of the cylinder.

3Fe + 40 = Fe ̧ ̧

32. The mass of a litre of the vapour of ferric chloride reduced by calculation to 0o C. and 760 m.m. is 14.56 grams. Find its molecular weight.

33. An iron ore contains 59.89 per cent. of iron as ferric oxide, and 14.44 per cent. of water, find its formula.

34. Find the percentage composition of magnetic pyrites (Fe,S,).

35. How many tons of hydrogen sulphate can be made from 10 tons of pyrites?

2FeS,+ 150+ 4H2O = Fe ̧ ̧ + 4H,SO,

2 3

36. Find the percentage composition of pyrrhotin if its formula be (a) Fe,S, (B) Fe,S,.

37. Iron nitride obtained by heating ferrous chloride in ammonia contains 9.3 per cent. of nitrogen. Find its formula.

38. What volume of sulphur dioxide at 39o C. can be obtained by passing air over 100 grams of ferrous disulphide heated to redness?

[blocks in formation]

39. 14 grams of iron are dissolved in hydrogen chloride, what volume of hydrogen at 13° C. is given off?

40.

[blocks in formation]

Two litres of gaseous hydrogen chloride are passed over heated iron, how much ferrous chloride is formed?

Fe + 2HCl = FeCl ̧ + H ̧.

41. 347 grams of ferrous sulphide are dissolved in hydrogen chloride, what volume of hydrogen sulphide at 11o C. is given off?

FeS + 2HCl = FeCl ̧ + H ̧S.

42. What volume of hydrogen sulphide at 17° C. is evolved on dissolving 489 grams of ferrous sulphide in acid? FeS + H2SO1 = FeSO4 + H2S.

43. What volume of hydrogen at 13° C. is evolved during the solution in dilute hydrogen sulphate of sufficient iron to form 1463 grams of crystallized ferrous sulphate?

Fe + H2SO, +7H,O= FeSO ̧ . 7H2O+ H ̧.

2

44. How much ferric oxide is obtained on drying the precipitate produced by ammonia in a solution of 187 grams of crystallized ferric nitrate ?

Fe,6NO. 18H,0 + 6NH ̧= 15H ̧0 + 6NHÂNО ̧ + Fé ̧¤ ̧

3

2

45. How much sulphur precipitates on passing 1.7 litres of hydrogen sulphide at 17° C. through an excess of solution of ferric chloride?

Fe,Cl + H,S= 2FeCl ̧ + 2HCl + S.

46. A salt contains iron 14 per cent., iodine 63.5 per cent., and water 22.5 per cent., find its formula.

47. During the solution of a gram of iron in dilute hydrogen chloride, 389-74 c.c. of hydrogen at 14° C. and 820 m.m. were evolved. Find the equivalent of iron.

fe+h cl=fe cl+h.

48. How much iron will one gram of potassium permanganate convert from ferrous into ferric salt?

10FeSO4 + KMn ̧ ̧ + 8H2SO ̧

2

2 8

= 5Fe ̧3SO ̧ + K2SO + 2MnSO ̧ + 8H ̧0.

4

« ΠροηγούμενηΣυνέχεια »