高压下氧气在水中溶解度计算、饱和蒸汽压

1、在25mpa压力下，液体中的溶解氧是多少？就是水，里面加了一些杀菌剂和防腐剂，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补充回答：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。水中溶解氧值则一般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25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

2、0.95o2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)=ko2po2=1.2810-8（1.0000-0.0313）01.013105o.2095=2.6310-4mol/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：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）。压力对氧气在水中溶解度的影响可用下列公式表述：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p

3、2的单位为帕）。p:25水饱和蒸汽压为3.169103pac1：=2.6310-4mol/l（相当于8.4mg/l）n2：8.9310-4mol/lc2：现在增压罐压力0.8mpa，即8.0105pa，计算得：c2=21.35610-4mol/l=0.1367g/l=0.0478l/l，约100l水溶解4.78l氧气计算得：c2=72.5110-4mol/l=0.203g/l=0.1624l/l，约100l水溶解16.24l氮气饱和蒸气压饱和蒸气压（saturated vapor pressure） 在密闭条件中，在一定温度下，与液体或固体处于相平衡的蒸气所具有的压力称为饱和蒸气压。同一物质在

4、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；对于同一物质，固态的饱和蒸汽压大于液态的饱和蒸汽压。例如，在30时，水的饱和蒸气压为4132.982pa,乙醇为10532.438pa。而在100时，水的饱和蒸气压增大到101324.72pa,乙醇为222647.74pa。饱和蒸气压是液体的一项重要物理性质，如液体的沸点、液体混合物的相对挥发度等都与之有关。 饱和蒸气压曲线 水在不同温度下的饱和蒸气压 saturated water vapor pressures at different temperatures 温度(tempe

5、rature)t/饱和蒸气压(saturated water vapor pressure)/(103pa)温度(temperature)t/饱和蒸气压(saturated water vapor pressure)/(103pa)温度(temperature)t/饱和蒸气压(saturated water vapor pressure)/(103pa)00.61129125232.012503973.610.65716126239.242514041.220.70605127246.662524109.630.75813128254.252534178.940.81359129262.042

6、544249.150.87260130270.022554320.260.93537131278.202564392.271.0021132286.572574465.181.0730133295.152584539.091.1482134303.932594613.7101.2281135312.932604689.4111.3129136322.142614766.1121.4027137331.572624843.7131.4979138341.222634922.3141.5988139351.092645001.8151.7056140361.192655082.3161.81851

7、41371.532665163.8171.9380142382.112675246.3182.0644143392.922685329.8192.1978144403.982695414.3202.3388145415.292705499.9212.4877146426.852715586.4222.6447147438.672725674.0232.8104148450.752735762.7242.9850149463.102745852.4253.1690150475.722755943.1263.3629151488.612766035.0273.5670152501.78277612

8、7.9283.7818153515.232786221.9294.0078154528.962796317.2304.2455155542.992806413.2314.4953156557.322816510.5324.7578157571.942826608.9335.0335158586.872836708.5345.3229159602.112846809.2355.6267160617.662856911.1365.9453161633.532867014.1376.2795162649.732877118.3386.6298163666.252887223.7396.9969164

9、683.102897330.2407.3814165700.292907438.0417.7840166717.832917547.0428.2054167735.702927657.2438.6463168753.942937768.6449.1075169772.522947881.3459.5898170791.472957995.24610.094171810.782968110.34710.620172830.472978226.84811.171173850.532988344.54911.745174870.982998463.55012.344175891.803008583.

10、85112.970176913.033018705.45213.623177934.643028828.35314.303178956.663038952.65415.012179979.093049078.25515.7521801001.93059205.15616.5221811025.23069333.45717.3241821048.93079463.15818.1591831073.03089594.25919.0281841097.53099726.76019.9321851122.53109860.56120.8731861147.93119995.86221.85118711

11、73.8312101336322.8681881200.1313102716423.9251891226.1314104106525.0221901254.2315105516626.1631911281.9316106946727.3471921310.1317108386828.5761931338.8318109846929.8521941368.0319111317031.1761951397.6320112797132.5491961427.8321114297233.9721971458.5322115817335.4481981489.7323117347436.97819915

12、21.4324118897538.5632001553.6325120467640.2052011568.4326122047741.9052021619.7327123647843.6652031653.6328125257945.4872041688.0329126888047.3732051722.9330128528149.3242061758.4331130198251.3422071794.5332131878353.4282081831.1333133578455.5852091868.4334135288557.8152101906.2335137018660.11921119

13、44.6336138768762.4992121983.6337140538864.9582132023.2338142328967.4962142063.4339144129070.1172152104.2340145949172.8232162145.7341147789275.6142172187.8342149649378.4942182230.5343151529481.4652192273.8344153429584.5292202317.8345155339687.6882212362.5346157279790.9452222407.8347159229894.30122324

14、53.8348161209997.7592242500.534916320100101.322252547.935016521101104.992262595.935116825102108.772272644.635216932103112.662282694.135317138104116.672292744.235417348105120.792302795.135517561106125.032312846.735617775107129.392322899.035717992108133.882332952.135818211109138.502343005.935918432110143.242353060.436018655111148.122363115.736118881112153.132373171.836219110113158.292383288.636319340114163.582393286.336419574115169.022403344.7365198