高压下氧气在水中溶解度计算、饱和蒸汽压

1、精品文档在25Mpa压力下，液体中的溶解氧是多少?就是水，里面加了 些杀菌剂和防腐剂，不过时间长了，可能已经被氧化掉了你可以按照水的溶解度计算氧在水中的溶解度和溶解氧值是两个既相区别而又相联系的概念。氧在水中的溶解度指的是水体和大气处于平衡时氧的最大溶解浓度，它的数值与温度、压力、水中溶质 量等因素有关。水中溶解氧值则股是指非平衡状态下的水中溶解氧的浓度。它的数值与水 体曝气作用、光合作用、呼吸作用及水中有机污染物的氧化作用等因素有关。这两个概念之 间的差异是由于大气和水体界面间氧气传质动力过程较慢而引起的。氧在水中的溶解度若已知当25c下水蒸气在空气中含量为0.0313摩尔分数以及干空气中含

2、20.95%。2时，则可应 用道尔顿分压定律和亨利定律算出标准条件下氧在水中溶解度O2(aq)：O2(aq) =Ko2 po2=1.28x10-8x (1.0000-0.0313) 0x1.013x105x0.2095=2.63x10-4mol/L (相当于8.4mg/L)由(4-2)式可导出在定压条件下温度对氧气在水中溶解度影响的关系式： 5 AH 11 "匕 5 2.303R Tl T2 .式中C1和C2分别为绝对温度T1和T2下气体在水中溶解度(mg/L)： H溶解热(J/mol)：R气体常数(8.314J/Kmol)0压力对氧气在水中溶解度的影响可用下列公式表述：C 1,01

3、3X05-p式中C1和C2分别为标准气压和P2气压下氧气在水中的溶解度(mg/L)：P确定温度下饱和水蒸气的压力(P和P2的单位为帕)。P:25水饱和蒸汽压为3.169xlO3PaCl： =2.63x10-4mol/L (相当于8.4mg/L) N2 : 8.93xia4mol/LC2：现在增压罐压力0.8MPa,即S.OxlCPa,计算得：C2=2L356x104moL/L=0.l367g/L=0.0478L/L,约 100L 水溶解 4.78L 氧气计算得:C272.5M Q 4moUL0.203f:/L=0.1624UL,约 100L 水溶解 1624L 氮气饱和蒸气压饱和蒸和压(sat

4、urated vapor pressure) 在密闭条件中，在定温度下,与液体 或固位处于相坨的蒸气所具有的压2l称为饱和蒸气压。同物画在不同温度下有不同的蒸 气压，并随着温度的升高而增大。不同液体饱和蒸汽压不同，溶质的饱和蒸汽压大于溶液的 饱和蒸汽压；对于同物质，固态的饱和蒸汽压大于液态的饱和蒸汽压。例如，在30C时， 水的饱和蒸气压为4132.982Pa,4醛为10532.438Pa。而在100C时，水的饱和蒸气压增大到 101324.72Pa,乙醇为222647.74Pa0饱和蒸气压是液体的项重要物理性质,如液体的沸点、 液体混佥物的相对挥发度等都与之有关。饱和蒸气压面级水在不同温度下的

5、饱和蒸气压 Saturated Water Vapor Pressures at Different Temperatures饱和蒸气压饱和蒸气压饱和蒸气压温度温度温度(Saturated(Saturated(Saturated(Temperature(Temperature(Temperaturewater vaporwater vaporwater vapor)pressure)pressure)pressure)t/vtrctiv/(x10A3Pa)/(x10A3Pa)/(x10A3Pa)00.61129125232.012503973.610.65716126239.242514041

6、.220.70605127246.662524109.630.75813128254.252534178.940.81359129262.042544249.150.87260130270.022554320.260.93537131278.202564392.271.0021132286.572574465.181.0730133295.152584539.091.1482134303.932594613.7101.2281135312.932604689.4111.3129136322.142614766.1121.4027137331.572624843.7131.4979138341.

7、222634922.3141.5988139351.092645001.8151.7056140361.192655082.3161.8185141371.532665163.8171.9380142382.112675246.3182.0644143392.922685329.8192.1978144403.982695414.3202.3388145415.292705499.9212.4877146426.852715586.4222.6447147438.672725674.0232.8104148450.752735762.7242.9850149463.102745852.4253

8、.1690150475.722755943.1263.3629151488.612766035.0273.5670152501.782776127.9283.7818153515.232786221.9294.0078154528.962796317.2304.2455155542.992806413.2314.4953156557.322816510.5324.7578157571.942826608.9335.0335158586.872836708.5345.3229159602.112846809.2355.6267160617.662856911.1365.9453161633.53

9、2867014.1376.2795162649.732877118.3386.6298163666.252887223.7396.9969164683.102897330.2407.3814165700.292907438.0417.7840166717.832917547.0428.2054167735.702927657.2438.6463168753.942937768.6449.1075169772.522947881.3459.5898170791.472957995.24610.094171810.782968110.34710.620172830.472978226.84811.

10、171173850.532988344.54911.745174870.982998463.55012.344175891.803008583.85112.970176913.033018705.45213.623177934.643028828.35314.303178956.663038952.65415.012179979.093049078.25515.7521801001.93059205.15616.5221811025.23069333.45717.3241821048.93079463.15818.1591831073.03089594.25919.0281841097.530

11、99726.76019.9321851122.53109860.56120.8731861147.93119995.86221.8511871173.8312101336322.8681881200.1313102716423.9251891226.1314104106525.0221901254.2315105516626.1631911281.9316106946727.3471921310.1317108386828.5761931338.8318109846929.8521941368.0319111317031.1761951397.6320112797132.5491961427.

12、8321114297233.9721971458.5322115817335.4481981489.7323117347436.9781991521.4324118897538.5632001553.6325120467640.2052011568.4326122047741.9052021619.7327123647843.6652031653.6328125257945.4872041688.0329126888047.3732051722.9330128528149.3242061758.4331130198251.3422071794.5332131878353.4282081831.

13、1333133578455.5852091868.4334135288557.8152101906.2335137018660.1192111944.6336138768762.4992121983.6337140538864.9582132023.2338142328967.4962142063.4339144129070.1172152104.2340145949172.8232162145.7341147789275.6142172187.8342149649378.4942182230.5343151529481.4652192273.8344153429584.5292202317.

14、8345155339687.6882212362.5346157279790.9452222407.8347159229894.3012232453.8348161209997.7592242500.534916320100101.322252547.935016521101104.992262595.935116825102108.772272644.635216932103112.662282694.135317138104116.672292744.235417348105120.792302795.135517561106125.032312846.735617775107129.392322899.035717992108133.882332952.135818211109138.502343005.935918432110143.242353060.436018655111148.122363115.736118881112153.132373171.836219110113158.292383288.636319340114163.582393286.336419574115169.022403344.7365