CHAPTER X. CARBON. C = 12, 1. A diamond (43.5) weighs 7 grams, what is its volume ? 2. The density of coal is 1.257. (a) How many cubic feet are occupied by a ton of coal? (B) What does a cubic yard of coal weigh? 3. How many pencil-leads 2 m.m. square and a decimetre long can be cut from a kilogram of graphite (A2-25)? 4. The specific heat of graphite is 198, what is its probable atomic weight? 5. Find the mass of 100 litres of carbon monoxide (CO) measured at 68° F. 6. 38 litres of carbon monoxide at 18° C. and 672 m.m. are required, how much dry hydrogen oxalate must be used? 7. 10 litres of carbon monoxide at 14° C. and 760 m.m. are required, what volume of normal carbon dioxide must be passed over red-hot carbon, and what mass of carbon is absorbed? 2 CO, + C = 2CO. L. A. C. 9 8. What volume is occupied by 100 grams of (a) carbon monoxide CO? (B) carbon dioxide CO,? 9. 30 c.c. of carbon monoxide are exploded with excess of oxygen, 35 c.c. of gas remain, what volume of oxygen was added? CO + 0 = CO2. 10. 50 c.c. of a mixture of carbon monoxide and hydrogen are exploded with excess of oxygen. 30 c.c. of gas remain, of which 20 c.c. are absorbed by potassium hydrate. What was the volume of the carbon monoxide and of the added oxygen? CO+O = CO2. 11. Find the mass of 10 litres of carbon monoxide (CO) measured at 39° C. and 800 m.m. 12. A substance contains carbon 20 26-6 per cent. and sulphur 53.3 per cent. per cent., oxygen Find its formula. 13. A diamond weighing 7 grams is burnt in oxygen, what volume of carbon dioxide is formed? 14. 10 grams of turpentine are burnt, what volume of carbon dioxide is formed? 15. 10 grams of common alcohol are burnt, what volume of carbon dioxide is formed? CH ̧0 + 60 = 3H ̧0 + 2CO,. 16. 10 lbs. of paraffin candles are burnt, what mass of carbon dioxide and of water is formed? C2H12+610=20CO, +21H ̧O. 42 17. 8.96 litres of carbon dioxide at 31° C. and 912 m.m. are required, how much marble must be used? CaCO2+ 2HCl = CaCl, + H2O + CO2. 2 18. 200 grams of platinum (sp. ht. 032) are cooled in solid carbon dioxide and then dropped into 100 grams of water at 16°C. If the temperature of the water fall to 10o C., what is the temperature of the carbon dioxide? 19. How much marble must be dissolved in acid to give 20 litres of carbon dioxide at 18° C. and 740 m.m.? CaCO2+ 2HCl = CaCl ̧ + H2O + CO,. 2 20. How much potassium and hydrogen carbonate is required to give a litre of carbon dioxide? KHCO3 + HCl = KCl + H2O + CO,. 21. At Paris in 1840 the daily production of carbon dioxide (CO) was 3 000 000 cubic metres. Find the mass of the gas. 22. 4 kilograms of carbon are burnt in an engine, which can apply 12 per cent. of the theoretical energy to external work. Through how many metres would the force suffice to lift 1000 kilograms? 23. 1000 volumes of water form 1092 volumes of ice. To what temperature Centigrade must 1000 volumes of mercury at 0° C. be heated to expand half as much? How much carbon must be burnt to heat the mercury, if volumes be reckoned in cubic inches? And also how much to melt the ice? (Latent heat of water 80. Sp. ht. of mercury 033. Coeff. of expansion of mercury for 1° C. 5550). 24. How many ounces avoirdupois of sodium and hydrogen carbonate and of hydrogen tartrate must be used to charge a gasogen holding 4 litres with gas under a pressure of 4 atmospheres? (1 volume of water at 10° C. absorbs 1.1847 volumes of carbon dioxide under 1 atmosphere). HNaCO,+CHO = C,H,NaO + H_O+CO. 6 6 25. Calcium hydrate is soluble in 730 times its mass of water, what volume of carbon dioxide at 13° C. is required to precipitate all the calcium from 3000 grams of lime-water? CaH,O, + CO, =H,O+CaCO.. 2 2 2 26. How many grams do 10 litres of marsh-gas (CH) weigh? 27. 10 grams of hexane are burnt, what volume of carbon dioxide is formed? 28. What is the percentage composition of (a) marshgas CH (B) ethene C,H,? (7) ethine C,H,? 2 29. 15.2 litres of methane at 17° C. and 870 m.m. are required, how much sodium acetate must be used? 2NaC ̧H2O2+ BаH ̧0,= BaCO ̧ + Na2CO2 + 2CH ̧.· 3 2 2 30. 374-166 c.c. of hydrogen diffuse through a certain apparatus in 10 seconds, what volume of ethene (CH) will diffuse under the same circumstances? 31. 25 c.c. of ethene are exploded with 100 c.c. of oxygen, what volume of carbon dioxide is formed, and what volume of oxygen is left? 32. Find the mass of a litre of (a) ethine CH,, (B) ethene C,H. 33. What is the percentage composition of potassium cyanide KCN? 34. Find the mass of 20 litres of cyanogen (C,N ̧). 35. 145 grams of potassium ferrocyanide were dissolved in 400 c.c. of water, and the density of the solution was found to be 1.16. By how much did the solution of the ferrocyanide increase the volume of the liquid? 36. Find the mass of 76 litres of marsh-gas (CH) measured at 31° C. 37. Find the mass of 1.51 litres of benzene (C.H.) vapour measured at 180° C. 38. What is the mass of 3.73 litres of ethene (C,H1) measured at 100° C ? 39. What volume of ethene at 16° C. and 750 m.m. is required to saturate 100 c.c. of bromine (A 3)? 40. Find the percentage of water in crystallized hydrogen oxalate (CH2O. 2H,O). 41. 100 grams of crystallized hydrogen oxalate are heated with hydrogen sulphate, what volume of carbon monoxide at 30° C. and 747 m.m. is evolved? C2H ̧ ̧.2H2O = 3H2O + CO2+ CO. 2 2 42. 100 litres of carbon monoxide at 14° C. and 1000 m.m. are required, how much sodium formate must be heated with hydrogen sulphate? NACHO+H2SO, NaHSO, + H2O + CO. = 4 43. The vapour-density of phenyl-naphthalene (C1 was determined by Meyer's third method. 0.1105 gram gave 13.2 c.c. of nitrogen at 17.5° C. The barometer stood at 7541 m.m., and the tension of the aqueous vapour was 14.9 m.m. Find the density of the vapour. 44. A substance contains carbon 53.16 percent., hydrogen Find its formula. 6.3 per cent., and oxygen 40.54 per cent. |