1、精品文檔在25Mpa壓力下，液體中的溶解氧是多少?就是水，里面加了 些殺菌劑和防腐劑，不過(guò)時(shí)間長(zhǎng)了，可能已經(jīng)被氧化掉了你可以按照水的溶解度計(jì)算氧在水中的溶解度和溶解氧值是兩個(gè)既相區(qū)別而又相聯(lián)系的概念。氧在水中的溶解度指的是水體和大氣處于平衡時(shí)氧的最大溶解濃度，它的數(shù)值與溫度、壓力、水中溶質(zhì) 量等因素有關(guān)。水中溶解氧值則股是指非平衡狀態(tài)下的水中溶解氧的濃度。它的數(shù)值與水 體曝氣作用、光合作用、呼吸作用及水中有機(jī)污染物的氧化作用等因素有關(guān)。這兩個(gè)概念之 間的差異是由于大氣和水體界面間氧氣傳質(zhì)動(dòng)力過(guò)程較慢而引起的。氧在水中的溶解度若已知當(dāng)25c下水蒸氣在空氣中含量為0.0313摩爾分?jǐn)?shù)以及干空氣中含

2、20.95%。2時(shí)，則可應(yīng) 用道爾頓分壓定律和亨利定律算出標(biāo)準(zhǔn)條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 (相當(dāng)于8.4mg/L)由(4-2)式可導(dǎo)出在定壓條件下溫度對(duì)氧氣在水中溶解度影響的關(guān)系式： 5 AH 11 "匕 5 2.303R Tl T2 .式中C1和C2分別為絕對(duì)溫度T1和T2下氣體在水中溶解度(mg/L)： H溶解熱(J/mol)：R氣體常數(shù)(8.314J/Kmol)0壓力對(duì)氧氣在水中溶解度的影響可用下列公式表述：C 1,01

3、3X05-p式中C1和C2分別為標(biāo)準(zhǔn)氣壓和P2氣壓下氧氣在水中的溶解度(mg/L)：P確定溫度下飽和水蒸氣的壓力(P和P2的單位為帕)。P:25水飽和蒸汽壓為3.169xlO3PaCl： =2.63x10-4mol/L (相當(dāng)于8.4mg/L) N2 : 8.93xia4mol/LC2：現(xiàn)在增壓罐壓力0.8MPa,即S.OxlCPa,計(jì)算得：C2=2L356x104moL/L=0.l367g/L=0.0478L/L,約 100L 水溶解 4.78L 氧氣計(jì)算得:C272.5M Q 4moUL0.203f:/L=0.1624UL,約 100L 水溶解 1624L 氮?dú)怙柡驼魵鈮猴柡驼艉蛪?sat

4、urated vapor pressure) 在密閉條件中，在定溫度下,與液體 或固位處于相坨的蒸氣所具有的壓2l稱為飽和蒸氣壓。同物畫(huà)在不同溫度下有不同的蒸 氣壓，并隨著溫度的升高而增大。不同液體飽和蒸汽壓不同，溶質(zhì)的飽和蒸汽壓大于溶液的 飽和蒸汽壓；對(duì)于同物質(zhì)，固態(tài)的飽和蒸汽壓大于液態(tài)的飽和蒸汽壓。例如，在30C時(shí)， 水的飽和蒸氣壓為4132.982Pa,4醛為10532.438Pa。而在100C時(shí)，水的飽和蒸氣壓增大到 101324.72Pa,乙醇為222647.74Pa0飽和蒸氣壓是液體的項(xiàng)重要物理性質(zhì),如液體的沸點(diǎn)、 液體混僉物的相對(duì)揮發(fā)度等都與之有關(guān)。飽和蒸氣壓面級(jí)水在不同溫度下的

5、飽和蒸氣壓 Saturated Water Vapor Pressures at Different Temperatures飽和蒸氣壓飽和蒸氣壓飽和蒸氣壓溫度溫度溫度(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