Help! Table of physical properties of oxygen and nitrogen
Thread Content
That classmate has tables of the physical properties of oxygen and nitrogen, or the equations used in pipeline design; please upload them, thank you! ! !
Gas-Liquid Property Estimation Handbook (5th Edition) - B.E. Pauling.pdf Handbook of Physical Properties for Chemistry and Chemical Engineering, Inorganic Volume.pdf I think these books are available on the website; they should contain the data you need.
Physical properties of oxygen: ① Color, taste, state: colorless and odorless gas (under standard conditions). ② Melting point: -218.4°C; Boiling point: -182.9°C. ③ Density: 1.429 grams per liter (gas), 1.419 grams per cubic centimeter (liquid), 1.426 grams per cubic centimeter (solid). ④ Water solubility: poorly soluble in water. ⑤ Storage: stored in sky-blue cylinders. Nitrogen: Elemental nitrogen is a colorless and odorless gas under normal conditions; its density as a gas at standard conditions is 1.25 g·dm-3. At standard atmospheric pressure, nitrogen turns into a colorless liquid when cooled to -195.8°C, and it becomes a snow-like solid when cooled to -209.86°C. Nitrogen has very low solubility in water; at normal temperature and pressure, about 0.02 volumes of nitrogen dissolve in 1 volume of water. It is a gas that is difficult to liquefy. Its solubility in water is very low; at 283 K, one volume of water can dissolve approximately 0.02 volumes of N2. At extremely low temperatures, nitrogen liquefies into a white liquid; further reduction in temperature results in the formation of a white crystalline solid.
There are relatively detailed explanations in this oxygen production worker Q&A. Page 104 has a chart showing the gas phase concentration and liquid phase concentration at gas-liquid equilibrium in the oxygen-nitrogen system.
http://baike.baidu.com/view/4885.html?wtp=tt http://baike.baidu.com/view/48978.htm
This post was last edited by yongjunzou on 2010-1-1 16:34. 1. Physical properties of oxygen: Oxygen is a colorless and odorless gas under normal conditions, accounting for about 20.9% of the total volume of air. Under standard conditions ①, the density of oxygen is 1.429 g/L, which is slightly higher than that of air (the density of air is 1.293 g/L). At a pressure of 1.01×105 Pa, oxygen turns into a pale blue liquid at around -183°C; the density of liquid oxygen is 1.143 kg/L. It becomes a pale blue crystalline solid in the form of snowflakes at around -218°C. Oxygen is slightly soluble in water; under normal conditions, only about 30 mL of oxygen can dissolve in 1 L of water. Fish rely on the oxygen dissolved in water to breathe and sustain life. Physical Properties of Oxygen
1. Name: Oxygen
2. Chemical formula: O2
3. CAS registry number: 7784-44-7
4. Relative molecular mass: 31.999
5. Melting point: 54.36 K, -218.79°C, -361.82°F
6. Boiling point at 101.325 kPa (1 atm): 90.17 K, -182.98°C, -297.36°F
7. Critical temperature: 154.58 K, -118.57°C, -181.43°F
8. Critical pressure: 5.04 mPa, 50.43 bar, 49.77 atm, 731.43 psia
9. Critical volume: 73.4 cm3/mol
10. Critical density: 0.436 g/cm3
11. Critical compressibility factor: 0.288
12. Eccentricity factor: 0.022
13. Liquid density at -140°C: 0.876/cm3
14. Liquid thermal expansion coefficient at -140°C: 0.00954 1/°C
15. Surface tension at -218°C: 22.5×10-3 N/m, 22.5 dyn/cm
16. Gas density at 101.325 kPa (atm) and 70°F (21.1°C): 1.325 kg/m3, 0.0827 lb/ft3
17. Gas relative density at 101.325 kPa (1 atm) and 70°F (air = 1): 1.105
18. Heat of vaporization at the boiling point: 210.63 kJ/kg, 90.57 BTU/lb
19. Heat of fusion at the melting point: 23.88 kJ/kg, 5.97 BTU/lb
20. Gas specific heat at constant pressure, cp at 25°C: 0.921 kJ/(kg•K), 0.22 BTU/(lb•R)
21. Gas specific heat at constant volume, cv at 25°C: 0.661 kJ/(kg•K), 0.158 BTU/(lb•R)
22. Ratio of specific heats of gas, cp/cv: 1.393
23. Liquid specific heat at -173°C: 1.729 kJ/(kg•K), 0.413 BTU/(lb•R)
24. Solid specific heat at -243°C: 0.894 kJ/(kg•K), 0.214 BTU/(lb•R)
25. Molar entropy of gas at 25°C: 205.04 J/(mol•K)
26. Molar entropy of formation of gas at 25°C: 0 J/(mol•K)
27. Molar enthalpy of formation of gas at 25°C: 0 kJ/mol
28. Molar Gibbs free energy of formation of gas at 25°C: 0 kJ/mol
29. Solubility parameter: 8.182 (J/cm3)0.5
30. Molar volume of liquid: 28.052 cm3/mol
31. Solubility in water at 25°C: 39.45×10-6 (ω)
32. Octanol-water partition coefficient, lgKow: ---
33. Henry’s law constant in water at 25°C: 4420.8 MPa/x, 43630.1 atm/(x)
34. Gas viscosity at 25°C: 201.74×10-7 Pa•s, 201.74 μP
35. Liquid viscosity at -130°C: 0.071 mPa•s, 0.071 cp
36. Gas thermal conductivity at 25°C: 0.02571 W/(m•K)
37. Liquid thermal conductivity at -150°C: 0.1206 W/(m•K)
38. Lower explosive limit in air: ---
39. Upper explosive limit in air: ---
40. Flash point: ---
41. Autoignition point: ---
42. Heat of combustion at 25°C (77°F) in gaseous state: ---
43. Threshold concentration according to the American Conference of Governmental Industrial Hygienists (ACGIH): ---
44. Permissible concentration value according to the U.S. Occupational Safety and Health Administration (OSHA): ---
45. Recommended concentration value according to the National Institute for Occupational Safety and Health (NIOSH): ---
2. Physical Properties of Nitrogen
Elemental nitrogen is a colorless and odorless gas under normal conditions, accounting for about 78% of the total volume of air. Its gas density under standard conditions is 1.25 g•dm-3. At standard atmospheric pressure, when cooled to -195.8°C, nitrogen turns into a colorless liquid with a density of 0.81 g/cm3 at -196°C. When cooled further to -209.86°C, liquid nitrogen becomes a snow-like solid. Nitrogen has very low solubility in water; at normal temperature and pressure, about 0.02 volumes of nitrogen dissolve in 1 volume of water. It is a gas that is difficult to liquefy. Its solubility in water is very low; at 283 K, one volume of water can dissolve approximately 0.02 volumes of N2. At extremely low temperatures, nitrogen liquefies into a white liquid; further reduction in temperature results in the formation of a white crystalline solid. Chemical formula: N2; Molecular weight: 28.01; Gas density: 1.251 kg/m3 (0°C, 1 atm); Liquid density: 0.809 kg/L (at boiling point); Specific gravity: 0.97 (air = 1); Boiling point: 77.4 K (1 atm); Melting point: 63.3 K (1 atm); Critical temperature: 126 K; Critical pressure: 33.5 atm, 3.399 MPa; Heat of vaporization: 47.7 cal/g, 199 kJ/kg (at boiling point). This substance is non-flammable but has asphyxiating properties. No special protection is generally required. However, when the oxygen concentration in the workplace air is below 18%, an air respirator, oxygen respirator, or long-tube mask must be worn. If nitrogen is inhaled, one should quickly leave the area and go to a place with fresh air. Keep the airway clear. If there is difficulty breathing, administer oxygen. If breathing stops, perform artificial respiration immediately. Seek medical attention. Emergency measures: Quickly evacuate people from the area contaminated by the leak to an upwind location, isolate the area, and strictly restrict access. It is recommended that emergency responders wear self-contained positive-pressure breathing apparatus and insulated clothing. Do not come into direct contact with the spill. Seal the source of leakage as much as possible. Use an exhaust fan to send the leaked air to an open area. Leaking containers must be properly handled, repaired, and inspected before being used again. Operational precautions: Perform in a sealed environment. Operate in a sealed environment with good natural ventilation. Operators must receive specialized training and strictly adhere to the operating procedures. It is recommended that operators wear cold-protective clothing and gloves. Prevent gas from leaking into the workplace air. Handle with care during transportation to prevent damage to the cylinders and accessories. Equipped with leak emergency response equipment. Physical Properties of Nitrogen
1. Name: Nitrogen
2. Chemical formula: N2
3. CAS registry number: 7727-37-9
4. Relative molecular mass: 28.013
5. Melting point: 63.15 K, -210°C, -346°F
6. Boiling point at 101.325 kPa (1 atm): 77.35 K, -195.8°C, -320.44°F
7. Critical temperature: 126.1 K, -147.05°C, -232.69°F
8. Critical pressure: 3.4 MPa, 33.94 bar, 33.5 atm, 492.26 psia
9. Critical volume: 90.1 cm3/mol
10. Critical density: 0.3109 g/cm3
11. Critical compressibility factor: 0.292
12. Eccentricity factor: 0.040
13. Density of liquid at -180°C: 0.729 g/cm3
14. Coefficient of thermal expansion of liquid at -180°C: 0.00753 per °C
15. Surface tension at -210°C: 12.2×10-3 N/m, 12.2 dyn/cm
16. Gas density at 101.325 kPa (atm) and 70°F (21.1°C): 1.160 kg/m3, 0.0724 lb/ft3
17. Relative gas density at 101.325 kPa (1 atm) and 70°F (air = 1): 0.967
18. Heat of vaporization at the boiling point: 202.76 kJ/kg, 87.19 BTU/lb
19. Heat of fusion at the melting point: 25.7 kJ/kg, 11.05 BTU/lb
20. Specific heat at constant pressure of gas at 25°C: 1.038 kJ/(kg•K), 0.248 BTU/(lb•R)
21. Specific heat at constant volume of gas at 25°C: 0.741 kJ/(kg•K), 0.177 BTU/(lb•R)
22. Ratio of specific heats of gas, cp/cv: 1.401
23. Specific heat of liquid at -183°C: 2.13 kJ/(kg•K), 0.509 BTU/(lb•R)
24. Specific heat of solid at -223°C: 1.489 kJ/(kg•K), 0.356 BTU/(lb•R)
25. Molar entropy of gas at 25°C: 191.5 J/(mol•K)
26. Molar entropy of formation of gas at 25°C: 0 J/(mol•K)
27. Molar enthalpy of formation of gas at 25°C: 0 kJ/mol
28. Molar Gibbs free energy of formation of gas at 25°C: 0 kJ/mol
29. Solubility parameter: 9.082 (J/cm3)0.5
30. Molar volume of liquid: 34.677 cm3/mol
31. Solubility in water at 25°C: 17.28×10-6 (w)
32. Octanol-water partition coefficient, lgKow: ---
33. Henry’s law constant in water at 25°C: 8829 Mpa/x, 87143.1 atm/(x)
34. Viscosity of gas at 25°C: 175.44×10-7 Pa•s, 175.44 μP
35. Viscosity of liquid at -150°C: 0.038 mPa•s, 0.038 cp
36. Thermal conductivity of gas at 25°C: 0.02475 W/(m•K)
37. Thermal conductivity of liquid at -150°C: 0.0646 W/(m•K)
38. Lower explosive limit in air: ---
39. Upper explosive limit in air: ---
40. Flash point: ---
41. Autoignition point: ---
42. Heat of combustion at 25°C (77°F) in gaseous state: ---
43. Threshold concentration according to the American Conference of Governmental Industrial Hygienists (ACGIH): ---
44. Permissible concentration value according to the Occupational Safety and Health Administration (OSHA): ---
45. Recommended concentration value according to the National Institute for Occupational Safety and Health (NIOSH): ---
Uses of Nitrogen
Nitrogen can be utilized in various commercial applications, including:
Chemical processes – used for inerting containers and protecting chemicals sensitive to oxygen, thereby reducing safety hazards by creating an oxygen-free environment ； Driving liquid through a pipe ； And the production of ammonia. Food---Nitrogen prevents oxidation, mold growth, moisture absorption, and pest infestation in packaged food, thereby extending its shelf life ； Can be quickly frozen ； And keeping perishable foods refrigerated during transportation. Oil recovery and refining---improving recovery efficiency and maintaining pressure in oil tanks and gas storage tanks ； Blanket inert protection storage tanks and product loading/unloading ； Purge pipeline ； As well as stripping volatile organic compounds (VOC) from wastewater streams or cooling the effluent streams. Metal production and processing – enables the protection of metals such as steel, copper, and aluminum during annealing, carburizing, and sintering operations in high-temperature furnaces ； Cooled extruded film ； Cold shrinkage fit of metal components ； Used for purging stainless steel pipe welding. It is also used for plasma cutting. Electrons – used to prevent oxidation in the manufacturing of semiconductors and printed circuits ； The recovery of solvents has been improved by avoiding the use of chlorofluorocarbon cleaners. Glass manufacturing — used to cool furnaces and prevent oxidation during production ； It is also used to lower the air temperature for optimal cooling efficiency. Research and health services---freezing and preservation of blood, physiological tissues, semen, and other biological specimens ； Freezing and destroying diseased tissue in cryosurgery and dermatological treatments ； It is also used for pre-cooling or isolating nuclear magnetic resonance imaging, thereby saving the more expensive helium. Construction—used to suppress the cooling temperature of concrete and prevent cracks from forming ； As well as for strengthening foundations. Chemical properties of nitrogen: Nitrogen is a fairly strong non-metal, ranking fourth after fluorine, oxygen, and chlorine. The N≡N bond in N2 molecules has a very high bond energy of 949 kJ/mol, making it difficult for them to dissociate into atoms; as a result, they exhibit stability and chemical inertness. Under high-temperature or discharge conditions, the chemical bonds in the molecule are broken, allowing it to react with various elements. To form NH3 from H2 ； Forms nitrides such as Mg3N2 and Ca3N2 with Mg, Ca, Sr, Ba ； It reacts slightly with O2 at high arc temperatures to produce NO; this endothermic reaction is rare when O2 combines with other substances. Alkali metals can only be used to synthesize lithium nitride, Li3N, through lithiation; they do not react directly with other alkali metals.
1. Name: Oxygen
2. Chemical formula: O2
3. CAS registry number: 7784-44-7
4. Relative molecular mass: 31.999
5. Melting point: 54.36 K, -218.79°C, -361.82°F
6. Boiling point at 101.325 kPa (1 atm): 90.17 K, -182.98°C, -297.36°F
7. Critical temperature: 154.58 K, -118.57°C, -181.43°F
8. Critical pressure: 5.04 mPa, 50.43 bar, 49.77 atm, 731.43 psia
9. Critical volume: 73.4 cm3/mol
10. Critical density: 0.436 g/cm3
11. Critical compressibility factor: 0.288
12. Eccentricity factor: 0.022
13. Liquid density at -140°C: 0.876/cm3
14. Liquid thermal expansion coefficient at -140°C: 0.00954 1/°C
15. Surface tension at -218°C: 22.5×10-3 N/m, 22.5 dyn/cm
16. Gas density at 101.325 kPa (atm) and 70°F (21.1°C): 1.325 kg/m3, 0.0827 lb/ft3
17. Gas relative density at 101.325 kPa (1 atm) and 70°F (air = 1): 1.105
18. Heat of vaporization at the boiling point: 210.63 kJ/kg, 90.57 BTU/lb
19. Heat of fusion at the melting point: 23.88 kJ/kg, 5.97 BTU/lb
20. Gas specific heat at constant pressure, cp at 25°C: 0.921 kJ/(kg•K), 0.22 BTU/(lb•R)
21. Gas specific heat at constant volume, cv at 25°C: 0.661 kJ/(kg•K), 0.158 BTU/(lb•R)
22. Ratio of specific heats of gas, cp/cv: 1.393
23. Liquid specific heat at -173°C: 1.729 kJ/(kg•K), 0.413 BTU/(lb•R)
24. Solid specific heat at -243°C: 0.894 kJ/(kg•K), 0.214 BTU/(lb•R)
25. Molar entropy of gas at 25°C: 205.04 J/(mol•K)
26. Molar entropy of formation of gas at 25°C: 0 J/(mol•K)
27. Molar enthalpy of formation of gas at 25°C: 0 kJ/mol
28. Molar Gibbs free energy of formation of gas at 25°C: 0 kJ/mol
29. Solubility parameter: 8.182 (J/cm3)0.5
30. Molar volume of liquid: 28.052 cm3/mol
31. Solubility in water at 25°C: 39.45×10-6 (ω)
32. Octanol-water partition coefficient, lgKow: ---
33. Henry’s law constant in water at 25°C: 4420.8 MPa/x, 43630.1 atm/(x)
34. Gas viscosity at 25°C: 201.74×10-7 Pa•s, 201.74 μP
35. Liquid viscosity at -130°C: 0.071 mPa•s, 0.071 cp
36. Gas thermal conductivity at 25°C: 0.02571 W/(m•K)
37. Liquid thermal conductivity at -150°C: 0.1206 W/(m•K)
38. Lower explosive limit in air: ---
39. Upper explosive limit in air: ---
40. Flash point: ---
41. Autoignition point: ---
42. Heat of combustion at 25°C (77°F) in gaseous state: ---
43. Threshold concentration according to the American Conference of Governmental Industrial Hygienists (ACGIH): ---
44. Permissible concentration value according to the U.S. Occupational Safety and Health Administration (OSHA): ---
45. Recommended concentration value according to the National Institute for Occupational Safety and Health (NIOSH): ---
2. Physical Properties of Nitrogen
Elemental nitrogen is a colorless and odorless gas under normal conditions, accounting for about 78% of the total volume of air. Its gas density under standard conditions is 1.25 g•dm-3. At standard atmospheric pressure, when cooled to -195.8°C, nitrogen turns into a colorless liquid with a density of 0.81 g/cm3 at -196°C. When cooled further to -209.86°C, liquid nitrogen becomes a snow-like solid. Nitrogen has very low solubility in water; at normal temperature and pressure, about 0.02 volumes of nitrogen dissolve in 1 volume of water. It is a gas that is difficult to liquefy. Its solubility in water is very low; at 283 K, one volume of water can dissolve approximately 0.02 volumes of N2. At extremely low temperatures, nitrogen liquefies into a white liquid; further reduction in temperature results in the formation of a white crystalline solid. Chemical formula: N2; Molecular weight: 28.01; Gas density: 1.251 kg/m3 (0°C, 1 atm); Liquid density: 0.809 kg/L (at boiling point); Specific gravity: 0.97 (air = 1); Boiling point: 77.4 K (1 atm); Melting point: 63.3 K (1 atm); Critical temperature: 126 K; Critical pressure: 33.5 atm, 3.399 MPa; Heat of vaporization: 47.7 cal/g, 199 kJ/kg (at boiling point). This substance is non-flammable but has asphyxiating properties. No special protection is generally required. However, when the oxygen concentration in the workplace air is below 18%, an air respirator, oxygen respirator, or long-tube mask must be worn. If nitrogen is inhaled, one should quickly leave the area and go to a place with fresh air. Keep the airway clear. If there is difficulty breathing, administer oxygen. If breathing stops, perform artificial respiration immediately. Seek medical attention. Emergency measures: Quickly evacuate people from the area contaminated by the leak to an upwind location, isolate the area, and strictly restrict access. It is recommended that emergency responders wear self-contained positive-pressure breathing apparatus and insulated clothing. Do not come into direct contact with the spill. Seal the source of leakage as much as possible. Use an exhaust fan to send the leaked air to an open area. Leaking containers must be properly handled, repaired, and inspected before being used again. Operational precautions: Perform in a sealed environment. Operate in a sealed environment with good natural ventilation. Operators must receive specialized training and strictly adhere to the operating procedures. It is recommended that operators wear cold-protective clothing and gloves. Prevent gas from leaking into the workplace air. Handle with care during transportation to prevent damage to the cylinders and accessories. Equipped with leak emergency response equipment. Physical Properties of Nitrogen
1. Name: Nitrogen
2. Chemical formula: N2
3. CAS registry number: 7727-37-9
4. Relative molecular mass: 28.013
5. Melting point: 63.15 K, -210°C, -346°F
6. Boiling point at 101.325 kPa (1 atm): 77.35 K, -195.8°C, -320.44°F
7. Critical temperature: 126.1 K, -147.05°C, -232.69°F
8. Critical pressure: 3.4 MPa, 33.94 bar, 33.5 atm, 492.26 psia
9. Critical volume: 90.1 cm3/mol
10. Critical density: 0.3109 g/cm3
11. Critical compressibility factor: 0.292
12. Eccentricity factor: 0.040
13. Density of liquid at -180°C: 0.729 g/cm3
14. Coefficient of thermal expansion of liquid at -180°C: 0.00753 per °C
15. Surface tension at -210°C: 12.2×10-3 N/m, 12.2 dyn/cm
16. Gas density at 101.325 kPa (atm) and 70°F (21.1°C): 1.160 kg/m3, 0.0724 lb/ft3
17. Relative gas density at 101.325 kPa (1 atm) and 70°F (air = 1): 0.967
18. Heat of vaporization at the boiling point: 202.76 kJ/kg, 87.19 BTU/lb
19. Heat of fusion at the melting point: 25.7 kJ/kg, 11.05 BTU/lb
20. Specific heat at constant pressure of gas at 25°C: 1.038 kJ/(kg•K), 0.248 BTU/(lb•R)
21. Specific heat at constant volume of gas at 25°C: 0.741 kJ/(kg•K), 0.177 BTU/(lb•R)
22. Ratio of specific heats of gas, cp/cv: 1.401
23. Specific heat of liquid at -183°C: 2.13 kJ/(kg•K), 0.509 BTU/(lb•R)
24. Specific heat of solid at -223°C: 1.489 kJ/(kg•K), 0.356 BTU/(lb•R)
25. Molar entropy of gas at 25°C: 191.5 J/(mol•K)
26. Molar entropy of formation of gas at 25°C: 0 J/(mol•K)
27. Molar enthalpy of formation of gas at 25°C: 0 kJ/mol
28. Molar Gibbs free energy of formation of gas at 25°C: 0 kJ/mol
29. Solubility parameter: 9.082 (J/cm3)0.5
30. Molar volume of liquid: 34.677 cm3/mol
31. Solubility in water at 25°C: 17.28×10-6 (w)
32. Octanol-water partition coefficient, lgKow: ---
33. Henry’s law constant in water at 25°C: 8829 Mpa/x, 87143.1 atm/(x)
34. Viscosity of gas at 25°C: 175.44×10-7 Pa•s, 175.44 μP
35. Viscosity of liquid at -150°C: 0.038 mPa•s, 0.038 cp
36. Thermal conductivity of gas at 25°C: 0.02475 W/(m•K)
37. Thermal conductivity of liquid at -150°C: 0.0646 W/(m•K)
38. Lower explosive limit in air: ---
39. Upper explosive limit in air: ---
40. Flash point: ---
41. Autoignition point: ---
42. Heat of combustion at 25°C (77°F) in gaseous state: ---
43. Threshold concentration according to the American Conference of Governmental Industrial Hygienists (ACGIH): ---
44. Permissible concentration value according to the Occupational Safety and Health Administration (OSHA): ---
45. Recommended concentration value according to the National Institute for Occupational Safety and Health (NIOSH): ---
Uses of Nitrogen
Nitrogen can be utilized in various commercial applications, including:
Chemical processes – used for inerting containers and protecting chemicals sensitive to oxygen, thereby reducing safety hazards by creating an oxygen-free environment ； Driving liquid through a pipe ； And the production of ammonia. Food---Nitrogen prevents oxidation, mold growth, moisture absorption, and pest infestation in packaged food, thereby extending its shelf life ； Can be quickly frozen ； And keeping perishable foods refrigerated during transportation. Oil recovery and refining---improving recovery efficiency and maintaining pressure in oil tanks and gas storage tanks ； Blanket inert protection storage tanks and product loading/unloading ； Purge pipeline ； As well as stripping volatile organic compounds (VOC) from wastewater streams or cooling the effluent streams. Metal production and processing – enables the protection of metals such as steel, copper, and aluminum during annealing, carburizing, and sintering operations in high-temperature furnaces ； Cooled extruded film ； Cold shrinkage fit of metal components ； Used for purging stainless steel pipe welding. It is also used for plasma cutting. Electrons – used to prevent oxidation in the manufacturing of semiconductors and printed circuits ； The recovery of solvents has been improved by avoiding the use of chlorofluorocarbon cleaners. Glass manufacturing — used to cool furnaces and prevent oxidation during production ； It is also used to lower the air temperature for optimal cooling efficiency. Research and health services---freezing and preservation of blood, physiological tissues, semen, and other biological specimens ； Freezing and destroying diseased tissue in cryosurgery and dermatological treatments ； It is also used for pre-cooling or isolating nuclear magnetic resonance imaging, thereby saving the more expensive helium. Construction—used to suppress the cooling temperature of concrete and prevent cracks from forming ； As well as for strengthening foundations. Chemical properties of nitrogen: Nitrogen is a fairly strong non-metal, ranking fourth after fluorine, oxygen, and chlorine. The N≡N bond in N2 molecules has a very high bond energy of 949 kJ/mol, making it difficult for them to dissociate into atoms; as a result, they exhibit stability and chemical inertness. Under high-temperature or discharge conditions, the chemical bonds in the molecule are broken, allowing it to react with various elements. To form NH3 from H2 ； Forms nitrides such as Mg3N2 and Ca3N2 with Mg, Ca, Sr, Ba ； It reacts slightly with O2 at high arc temperatures to produce NO; this endothermic reaction is rare when O2 combines with other substances. Alkali metals can only be used to synthesize lithium nitride, Li3N, through lithiation; they do not react directly with other alkali metals.
The 7th floor is written very well; learned a lot
The 7th floor is written very well; learned a lot
Great stuff! Learn it!* . Saved!
The unit is atmospheres. 1. Nitrogen: Pressure, Boiling point (atmospheres), (°C): 0.2 –207.25; 0.3 –204.73; 0.4 –202.81; 0.5 –201.23; 0.6 –199.88; 0.7 –198.70; 0.8 –197.64; 0.9 –196.68; 1.0 –195.80; 1.1 –194.98; 1.2 –194.21; 1.3 –193.50; 1.4 –192.82; 1.5 –192.18; 1.6 –191.57; 1.7 –190.99; 1.8 –190.44; 1.9 –189.90; 2.0 –189.39; 2.1 –188.90; 2.2 –188.42; 2.3 –187.96; 2.4 –187.52; 2.5 –187.08; 2.6 –186.66; 2.7 –186.26; 2.8 –185.86; 2.9 –185.47; 3.0 –185.10; 4 –181.76; 5 –178.99; 6 –176.59; 7 –174.47; 8 –172.56; 9 –170.81; 10 –169.20; 11 –167.70; 12 –166.29; 13 –164.97; 14 –163.71; 15 –162.52; 16 –161.39; 17 –160.30; 18 –159.26; 19 –158.26; 20 –157.30; 21 –156.38; 22 –155.48; 23 –154.62; 24 –153.78; 25 –152.97; 26 –152.19; 27 –151.42; 28 –150.68; 29 –149.96; 30 –149.26. 2. Oxygen: Pressure, Boiling point (atmospheres), (°C): 0.2 –195.96; 0.3 –193.08; 0.4 –190.89; 0.5 –189.10; 0.6 –187.58; 0.7 –186.24; 0.8 –185.04; 0.9 –183.96; 1.0 –182.96; 1.1 –182.04; 1.2 –181.18; 1.3 –180.38; 1.4 –179.62; 1.5 –178.90; 1.6 –178.21; 1.7 –177.56; 1.8 –176.94; 1.9 –176.34; 2.0 –175.77; 2.1 –175.21; 2.2 –174.68; 2.3 –174.16; 2.4 –173.67; 2.5 –173.18; 2.6 –172.71; 2.7 –172.26; 2.8 –171.81; 2.9 –171.38; 3.0 –170.96; 4 –167.24; 5 –164.16; 6 –161.50; 7 –159.14; 8 –157.02; 9 –155.09; 10 –153.30; 11 –151.64; 12 –150.08; 13 –148.62; 14 –147.23; 15 –145.91; 16 –144.66; 17 –143.46; 18 –142.30; 19 –141.20; 20 –140.13; 21 –139.10; 22 –138.11; 23 –137.15; 24 –136.22; 25 –135.31; 26 –134.43; 27 –133.58; 28 –132.75; 29 –131.94; 30 –131.15