燈火實(shí)驗(yàn)是真的嗎

1、“燈火實(shí)驗(yàn)”是真的嗎？利用數(shù)字化手持技術(shù)探究“燈火實(shí)驗(yàn)”的科學(xué)性安徽蚌埠九中毛思哲蒲麗麗摘要：本文運(yùn)用數(shù)字化傳感器，用蠟燭在密閉空間里燃燒來模擬地窖中場景的方式，對(duì)空氣成分進(jìn)行了探究， 通過實(shí)驗(yàn)和數(shù)據(jù)說明了影響蠟燭熄滅的本質(zhì)原因，科學(xué)地分析了這一傳統(tǒng)做法的依據(jù)， 同時(shí)也體現(xiàn)了數(shù)字化傳感器在傳統(tǒng)實(shí)驗(yàn)中的優(yōu)勢！關(guān)鍵詞：燈火實(shí)驗(yàn)地窖 數(shù)字化傳感器蠟燭熄滅空氣成分長期以來，人們?cè)谶M(jìn)入久未開啟的地窖之前，必須做燈火實(shí)驗(yàn)，如果燈火熄滅或燈火忽明忽暗，則二氧化碳濃度高，人員不能進(jìn)入地窖，如果火焰正常，就可以進(jìn)入。人教版九年級(jí)化學(xué)關(guān)于二氧化碳對(duì)人體健康是這樣表述的： 二氧化碳對(duì)人體健康危害較大， 微量二氧化碳

2、能促使人的呼吸加快， 呼吸量增加。 當(dāng)空氣中二氧化碳濃度達(dá)到 1時(shí)，人的呼吸變得急促；二氧化碳濃度達(dá)到 5時(shí)，人的呼吸感到困難，伴有耳鳴和血液流動(dòng)加快的感覺；二氧化碳濃度達(dá)到10 20時(shí)，人的呼吸將處于停頓狀態(tài)并失去知覺， 時(shí)間稍長就會(huì)有生命危險(xiǎn)； 二氧化碳濃度達(dá)到 20 25時(shí)，人將窒息死亡?？諝庵醒鯕鉂舛葴p少，人的呼吸就會(huì)感到困難， 嚴(yán)重時(shí)會(huì)因缺氧而死亡。 當(dāng)空氣中氧氣濃度下降到 17%時(shí)，人在靜止?fàn)顟B(tài)下尚無影響， 如果從事強(qiáng)度較大的活動(dòng)或勞動(dòng)時(shí)就會(huì)呼吸困難和心跳加速，引起喘息；當(dāng)氧氣濃度下降到 15%時(shí)，人就會(huì)呼吸急促，感到遲鈍，以致不能從事勞動(dòng)或活動(dòng)；當(dāng)氧氣濃度下降到 10%-12%時(shí)

3、，人就會(huì)失去理智，如果時(shí)間稍長就會(huì)對(duì)生命構(gòu)成威脅；當(dāng)氧氣濃度下降到 6%-9%時(shí)，人則會(huì)失去知覺，如果不及時(shí)進(jìn)行搶救就會(huì)造成死亡。 煤礦安全規(guī)程規(guī)定，采掘工作面空氣中氧氣濃度不得低于 20% 。燈火實(shí)驗(yàn)結(jié)果真的能確保人們不會(huì)受到傷害嗎？我們對(duì)此展開探究。我們采用在密閉容器中燃燒蠟燭的方式來模擬探究地窖中空氣的成分。一、 提出假設(shè) :二氧化碳能使蠟燭熄滅，蠟燭在密閉空間里燃燒一段時(shí)間也會(huì)熄滅，那么在密閉空間里蠟燭自然熄滅時(shí)到底是由二氧化碳濃度增大引起的，還是由氧氣濃度降低引起的， 又或者是二者共同作用引起的， 氧氣和二氧化碳引起蠟燭熄滅的極限濃度大約是多少？由于這是一組由定性到定量的實(shí)驗(yàn)， 來探

4、究進(jìn)入久未開啟的地窖中二氧化碳與氧氣的濃度， 看看對(duì)人是否是安全的， 我們使用數(shù)字化傳感器來完成實(shí)驗(yàn)（本實(shí)驗(yàn)采用威尼爾氧氣與二氧化碳傳感器） 。二、設(shè)計(jì)思路： 為了能使實(shí)驗(yàn)結(jié)果更科學(xué)，我們需要做三組對(duì)比實(shí)驗(yàn)。第一組，將二氧化碳傳感器和氧氣傳感器放在火焰附近上部空間， 測量火焰燃燒直至熄滅時(shí)二氧化碳和氧氣的濃度。 第二組，將第一組實(shí)驗(yàn)作為空白實(shí)驗(yàn)， 向其中補(bǔ)充二氧化碳，增大二氧化碳的濃度直至蠟燭熄滅， 而氧氣的濃度變化與第一組大約相近。第三組，將第一組實(shí)驗(yàn)作為空白實(shí)驗(yàn)，向其中補(bǔ)充氧氣直至蠟燭熄滅。每個(gè)實(shí)驗(yàn)做 3 次取平均值。三、實(shí)驗(yàn)過程：1、實(shí)驗(yàn)原理：同時(shí)利用氧氣傳感器和二氧化碳傳感器測定蠟燭在

5、密閉空間里燃燒至熄滅時(shí)氧氣和二氧化碳的濃度，從定性和定量兩個(gè)方面探究蠟燭熄滅的原因。2、實(shí)驗(yàn)器材：計(jì)算機(jī)、數(shù)據(jù)采集器、 氧氣傳感器、二氧化碳傳感器、 五升油桶、橡皮泥、錐形瓶、分液漏斗、廣口瓶、大試管、單孔橡皮塞導(dǎo)氣管、酒精燈、鐵架臺(tái)、大理石、稀鹽酸、高錳酸鉀。3、實(shí)驗(yàn)步驟：1）將五升油桶去底于兩側(cè)中部對(duì)稱開兩個(gè)口，將氧氣傳感器和二氧化碳傳感器放入孔內(nèi)用橡皮泥固定好， 上端用橡皮泥封口， 在水槽中央固定一支長約六七厘米的蠟燭，然后向水槽里放入兩厘米厚的油層， 連接好傳感器， 數(shù)據(jù)采集器和計(jì)算機(jī)，點(diǎn)燃蠟燭，迅速罩上油桶，同時(shí)點(diǎn)擊數(shù)據(jù)采集器，直至蠟燭熄滅，點(diǎn)擊軟件保存圖像和數(shù)據(jù)。2）利用第一步裝置

6、，同時(shí)用大理石和稀鹽酸制取二氧化碳，一切準(zhǔn)備就緒后，點(diǎn)燃蠟燭，罩上油桶，向其中通入二氧化碳，點(diǎn)擊數(shù)據(jù)采集器，直至蠟燭熄滅，保存圖像和數(shù)據(jù)。3）利用第一步裝置， 同時(shí)用高錳酸鉀制取氧氣， 待氧氣大量產(chǎn)生時(shí)， 點(diǎn)燃蠟燭，罩上油桶，向其中通入氧氣， 點(diǎn)擊數(shù)據(jù)采集器， 直至蠟燭熄滅， 保存圖像和數(shù)據(jù)。4. 實(shí)驗(yàn)圖像（每組實(shí)驗(yàn)圖像和數(shù)據(jù)各展示三次實(shí)驗(yàn)結(jié)果）第一組實(shí)驗(yàn)：正常情況下蠟燭在密閉空間直至熄滅時(shí)氧氣和二氧化碳濃度變化曲線第一次第二次第三次第二組實(shí)驗(yàn)：通入二氧化碳， 蠟燭在密閉空間直至熄滅時(shí)氧氣和二氧化碳濃度變化曲線第一次第二次第三次第三組實(shí)驗(yàn)：通入氧氣，蠟燭在密閉空間直至熄滅時(shí)氧氣和二氧化碳濃度變

7、化曲線第一次第二次第三次數(shù)據(jù)記錄第一組實(shí)驗(yàn)數(shù)據(jù)第一次時(shí)間（ s）氧氣濃度（ %）二氧化碳（ ppm)0 20.0606700435 392.9138183594 19.9776738416 392.9138183598 19.8290160878 394.82116699212 19.7218564348 457.76367187516 19.4035292303 566.48254394520 18.8850656152 726.69982910224 18.3371856247 905.99060058628 17.8665236195 1180.6488037132 17.5681575

8、268 1529.6936035236 17.2503556148 1947.402954140 16.9141684682 2492.9046630944 16.4545376037 3120.4223632848 16.0542647823 3911.972045952 15.8052761768 4859.9243164156 15.5678440045 5849.8382568460 15.3445947275 6866.4550781364 15.1633688438 7951.736450268 14.9658588952 9080.8868408272 14.8555474877

9、 10147.094726676 14.7914618129 11209.48791580 14.6942827158 12264.251709第二次0 20.4619934497 394.8211669924 20.3474797029 394.8211669928 20.1788608372 398.63586425812 19.9781991341 423.43139648416 19.6861365504 488.2812520 19.329988292 608.44421386724 18.9969528999 755.31005859428 18.7085673632 928.87

10、87841832 18.4417188156 1159.6679687536 18.1864267011 1430.5114746140 17.9568739151 1754.7607421944 17.7514845802 2103.8055419948 17.6227879382 2513.8854980552 17.3963869066 2988.8153076256 17.1684099978 3547.6684570360 16.9950635004 4186.6302490264 16.8332734361 4901.8859863368 16.6341876102 5634.30

11、78613372 16.4550628961 6395.3399658276 16.2701599655 7221.2219238380 16.0983893453 8113.8610839884 15.9402763279 9002.6855468888 15.7921438664 9849.5483398492 15.6597701774 10704.040527396 15.5405287989 11573.7915039100 15.4465014563 12435.9130859第三次0 20.7640365892 408.1726074224 20.6558263514 404.3

12、579101568 20.5213514928 415.80200195312 20.1893666855 455.85632324216 19.8663118493 497.81799316420 19.582128652 595.09277343824 19.182381123 722.88513183628 18.8467192688 873.56567382832 18.5467772989 1092.910766636 18.2667964409 1344.6807861340 18.0193837127 1667.0227050844 17.7772239086 2042.7703

13、857448 17.5718345738 2479.5532226652 17.3412312029 2967.8344726656 17.0586238828 3561.0198974660 16.7665612992 4240.0360107464 16.5758801519 5027.7709960968 16.3689149398 5817.4133300872 16.1146734102 6669.9981689576 15.8940505952 7583.6181640680 15.6807818741 8586.8835449284 15.5027077449 9485.2447

14、509888 15.3640305469 10431.2896729第二組實(shí)驗(yàn)數(shù)據(jù)第一次時(shí)間（ s）氧氣濃度（ %）二氧化碳（ ppm)0 20.5870130449 461.578369141420.343802656537.8723144538 20.0738023539 658.0352783212 19.8279655029 814.43786621116 19.4991324501 1005.1727294920 19.1550659173 1258.8500976624 18.8682562578 1564.0258789128 18.6255711614 1932.1441650

15、432 18.3440144261 2412.7960205136 18.0734888316 3070.8312988340 17.8470878 3894.805908244 17.6128073822 4886.6271972748 17.3727487479 5872.7264404352 17.1258613121 6916.0461425856 16.9383319194 7995.6054687560 16.7434484328 9073.2574462964 16.5312302965 10084.152221768 16.3458020735 11093.139648472

16、16.1419886159 12012.481689576 15.9796732591 12916.56494148015.86726068213792.0379639第二次時(shí)間（ s）氧氣濃度（ %）二氧化碳（ ppm)0 20.6274605609 478.7445068364 20.5681025179 501.632690438 20.4378299986 509.26208496112 20.2902228295 545.50170898416 20.0895611264 608.44421386720 19.9130628744 713.34838867224 19.7260587

17、741 835.41870117228 19.5411558435 989.9139404332 19.3683346384 1209.259033236 19.21652513 1464.8437540 19.0836261486 1781.4636230544 18.9559800914 2147.6745605548 18.8388398825 2573.0133056652 18.7290537675 3059.3872070356 18.6155906055 3625.8697509860 18.4910963028 4278.182983464 18.3676525849 5008

18、.6975097768 18.2295006793 5729.6752929772 18.0918740662 6494.5220947376 17.97315798 7310.8673095780 17.840784291 8235.9313964884 17.7000059234 9092.3309326288 17.5765622055 9954.4525146592 17.4552196573 10862.350463996 17.3254724304 11735.9161377100 17.1878458172 12617.111206110417.06650326913481.14

19、0136710816.9446354284 14339.447021511216.83695048315115.73791511616.7444990177 15903.472900412016.6520475523 16933.441162112416.58481012318232.345581112816.5716778126 19376.754760713216.6221058846 20561.2182617第三次時(shí)間（ s）氧氣濃度（ %）二氧化碳（ ppm)0 20.6085500339 427.246093754 20.5759819041 429.1534423838 20.4

20、520128938 425.33874511712 20.2313900788 465.39306640616 19.9624403616 509.26208496120 19.6961171064 587.46337890624 19.4187627104 699.99694824228 19.166097058 841.1407470732 18.9502018748 1010.8947753936 18.7894623954 1245.4986572340 18.631349378 1512.5274658244 18.4595787578 1829.1473388748 18.2767

21、769968 2195.3582763752 18.1454538926 2601.6235351656 18.0020490629 3089.9047851660 17.850764847 3646.8505859464 17.7021070931 4268.6462402368 17.5376905667 4953.3843994172 17.359091145 5624.7711181676 17.1558029798 6311.4166259880 16.9745770961 7059.0972900484 16.8085846925 7827.7587890688 16.672533

22、9566 8712.7685546992 16.5060162605 9475.7080078196 16.3421250266 10290.145874100 16.1924166878 11106.4910889104 16.0742258941 11949.5391846108 16.0101402193 12817.3828125112 16.0012102482 13658.5235596116 16.0269495766 14490.1275635第三組實(shí)驗(yàn)數(shù)據(jù)第一次時(shí)間（ s）氧氣濃度（ %）二氧化碳（ ppm)0 20.3422267787 478.7445068364 20.

23、1457674149 545.5017089848 19.9204169682 658.0352783212 19.6892883049 810.62316894516 19.4487043782 1010.8947753920 19.191311094 1256.9427490224 18.8887426621 1579.2846679728 18.6586645836 1945.4956054732 18.4790145772 2376.5563964836 18.2767769968 2870.5596923840 18.2095395675 3419.8760986344 18.815

24、2017238 4098.8922119148 19.7481210556 4844.6655273452 19.6546190055 5588.5314941456 19.4870507246 6362.9150390660 19.2590738158 7162.0941162164 18.9670112322 7995.6054687568 18.7821083015 8853.9123535272 18.7826335939 9603.5003662176 18.8861162 10389.328002980 18.8524974853 11154.174804784 18.815727

25、0162 11884.689331188 18.7721277456 12622.83325292 18.6828280348 13315.200805796 18.6056100496 14032.3638916100 18.5567578548 14705.657959104 18.5068550752 15296.9360352108 18.4243841658 15895.8435059112 18.2552400077 16805.6488037116 18.2646952712 17934.7991943120 18.3392867944 18924.7131348124 18.3

26、046174949 19964.2181396128 18.2499870835 20898.8189697132 18.2337030186 21596.9085693136 18.1533332789 22184.3719482140 18.1039557917 22939.6820068144 18.0593059363 23649.2156982148 17.9889167525 24541.8548584152 17.9106481824 25247.5738525156 17.8113679157 26174.5452881160 17.6921265371 27126.31225

27、59164 17.54189290628182.9833984168 17.3722234555 29197.6928711172 17.1957252035 30120.8496094176 17.0391880634 31105.0415039180 16.9010361578 32011.0321045184 16.7817947792 32878.8757324188 16.6961721153 33880.2337646192 16.7444990177 34738.5406494196 16.9194213924 35701.751709第二次時(shí)間（ s）氧氣濃度（ %）二氧化碳（

28、 ppm)020.5885889221 488.28125120.5864877524 488.28125220.5812348283 488.281253 20.5738807344 488.281254 20.5612737164 486.3739013675 20.5407873122 486.373901367620.510320352486.373901367720.4625187421486.373901367820.4210206412488.28125920.3774213706507.3547363281020.3343473925507.35473632811 20.287

29、5963674 507.3547363281220.2418959272 507.35473632813 20.1972460718 511.1694335941420.1499697543 537.87231445315 20.1011175595 541.68701171916 20.0517400724 566.48254394517 19.9981602459 570.29724121118 19.9409033725 59319.8825959142 595.09277343820 19.824288456 616.07360839821 19.771233

30、9219 637.05444335922 19.7218564348 659.94262695323 19.6740548249 661.84997558624 19.6236267529 692.36755371125 19.5731986809 722.88513183626 19.5227706089 766.75415039127 19.4728678293 793.4570312528 19.4224397573 823.97460937529 19.3720116853 865.93627929730 19.3310388768 892.63916015631 19.2911166

31、532 947.95227050832 19.2532955992 993.72863769533 19.2149492528 1050.9490966834 19.1792293685 1102.4475097735 19.144560069 1146.3165283236 19.1093654771 1199.7222900437 19.0757467624 1249.3133544938 19.0400268781 1327.5146484439 19.0064081634 1373.2910156340 18.9691124018 1455.3070068441 18.92866488

32、58 1529.6936035242 18.8850656152 1581.192016643 18.8430422219 1682.2814941444 18.8025947058 1752.8533935545 18.7631977745 1832.9620361346 18.7253767205 1897.8118896547 18.6859797893 1995.0866699248 18.6465828581 2092.361450249 18.6077112192 2166.7480468850 18.5677889956 2262.1154785251 18.5283920643

33、 2355.5755615252 18.4879445483 2470.0164794953 18.4495982018 2573.0133056654 18.4096759782 2695.0836181655 18.3692284621 2788.5437011756 18.3119715887 2908.7066650457 18.2746758271 3030.7769775458 18.2415824049 3147.1252441459 18.218994831 3273.0102539160 18.2069131054 3414.1540527361 18.2037613509

34、3541.9464111362 18.2174189537 3694.5343017663 18.2515629608 3845.2148437564 18.3130221735 3999.7100830165 18.3923413284 4131.3171386766 18.4569522957 4344.9401855567 18.5215632629 4501.3427734468 18.593528324 4674.9114990269 18.6765245258 4829.4067382870 18.7716024532 5010.604858471 18.8756103517 51

35、76.5441894572 18.9911746833 5346.2982177773 19.1198713254 5510.330200274 19.2548714764 5689.6209716875 19.3945992592 5851.7456054776 19.5353776269 6017.6849365277 19.6688019007 6198.8830566478 19.8001250048 6391.5252685579 19.9256698924 6587.9821777380 20.038607762 6757.7362060581 20.1389386135 6961

36、.8225097782 20.2256118623 7141.1132812583 20.2928492916 7333.7554931684 20.3390750242 7514.9536132885 20.3653396451 7690.429687586 20.3774213706 7923.126220787 20.3837248796 8150.1007080188 20.3842501721 8375.1678466889 20.3837248796 8558.2733154390 20.3884525114 8728.0273437591 20.406837746 8914.94

37、75097792 20.4472852621 9086.6088867293 20.5108456445 9296.4172363394 20.5765071965 9464.2639160295 20.6390169941 9674.0722656396 20.6973244523 9857.1777343897 20.7456513547 10053.634643698 20.7845229935 10248.184204199 20.8249705096 10454.1778564100 20.8738227043 10620.1171875101 20.9310795777 10829

38、.9255371102 20.9904376208 11001.5869141103 21.0476944942 11198.0438232104 21.1017996131 11404.0374756105 21.1485506382 11592.8649902106 21.1900487391 11774.0631104107 21.2257686234 11968.6126709108 21.256760876 12210.8459473109 21.2803990347 12411.1175537110 21.2998348541 12571.3348389111 21.3260994

39、75 12752.532959112 21.3654964062 12922.2869873113 21.4122474313 13105.3924561114 21.4568972867 13277.053833115 21.4873642469 13467.7886963116 21.5083759435 13664.2456055117 21.5209829615 13820.6481934118 21.5267611781 14019.0124512119 21.5215082539 14204.0252686120 21.5025977269 14381.4086914121 21.

40、4726560592 14583.5876465122 21.4353602976 14730.4534912123 21.4001657057 14900.2075195124 21.3686481607 15062.3321533125 21.3471111716 15226.3641357126 21.3355547385 15398.0255127127 21.3329282764 15539.1693115128 21.3350294461 15722.2747803129 21.3397570778 15899.6582031130 21.3460605868 16096.1151

41、123131 21.3581423124 16246.7956543132 21.3744263773 16443.2525635133 21.395438074 16778.9459229134 21.4138233085 17103.1951904135 21.4253797417 17381.6680908136 21.4327338355 17728.805542137 21.4374614673 18041.6107178138 21.4369361749 18306.7321777139 21.42958208118596.6491699140 21.4132980161 1887

42、5.1220703141 21.3849322256 19090.6524658142 21.3502629261 19388.1988525143 21.3108659949 19670.4864502144 21.2746208181 19968.0328369145 21.2362744717 20223.6175537146 21.1974028329 20481.1096191147 21.1569553168 20759.5825195148 21.1154572159 21005.6304932149 21.0744844074 21158.2183838150 21.03246

43、10141 21278.3813477151 20.9888617435 21537.7807617152 20.9463130578 21690.3686523153 20.9063908341 21854.4006348154 20.8764491664 22018.4326172155 20.8522857152 22216.796875156 20.8323246034 22504.8065186157 20.8118381992 22630.6915283158 20.78767474822949.21875159 20.7593089575 23130.4168701160 20.

44、7304178746 23349.7619629161 20.6973244523 23656.8450928162 20.6642310301 23954.3914795163 20.63008702324087.9058838164 20.5990947704 24360.6567383165 20.5649507634 24671.5545654166 20.5318573411 24879.4555664167 20.4956121644 25211.3342285168 20.45096230925556.5643311169 20.4210206412 25876.99890141

45、70 20.3905536811 26155.4718018171 20.3606120133 26535.0341797172 20.3317209304 26817.3217773173 20.3002033854 27187.3474121174 20.2692111328 27555.4656982175 20.23664300327854.9194336176 20.20512545828247.833252177 20.1709814509 28558.7310791178 20.1378880287 28881.072998179 20.1021681444 29228.2104

46、492180 20.0690747221 29504.776001181 20.0328295454 29962.5396729182 19.9981602459 30246.7346191183 19.9640162388 30765.5334473184 19.93144810931002.0446777185 19.8988799792 31316.7572021186 19.8715647735 31694.4122314187 19.8437242754 31990.0512695188 19.8216619939 32455.4443359189 19.8085296835 327

47、70.1568604190 19.80537792932997.1313477191 19.81168143833411.026001192 19.82428845633720.0164795193 19.8458254451 34193.0389404194 19.8731406507 34542.0837402195 19.9067593654 34944.5343018196 19.9456310042 35497.6654053197 19.9929073217 35852.432251198 20.0522653648 36273.9562988199 20.1263315955 3

48、6619.1864014200 20.2140554291 36966.3238525201 20.3159621579 37445.0683594202 20.4346782441 37862.77771203 20.5712542724 38343.4295654204 20.6978497448 38751.6021729205 20.8244452171 39367.6757813206 20.95156598239907.4554443207 21.0797373316 40309.9060059208 21.2021304647 40702.8198242209 21.307714

49、2404 41271.2097168210 21.3880839801 41748.046875211 21.4432396839 42226.7913818212 21.48001015342654.0374756213 21.5157300374 43174.7436523214 21.5614304776 43645.8587646215 21.6144850117 43954.8492432216 21.6664889609 44290.5426025217 21.7179676177 44691.0858154218 21.7652439352 45001.9836426219 21

50、.8004385271 45520.7824707220 21.8188237617 46043.3959961221 21.8188237617 46340.9423828222 21.80148911246836.8530273223 21.7704968594 47130.5847168224 21.7289987585 47615.0512695225 21.6838236107 47863.0065918226 21.6354967083 48278.8085938227 21.5850686363 48679.3518066228 21.5188817919 49093.24646229 21.4574225791 49356.4605713230 21.3912357346 49980.1635742231 21.3203212584 50338.7451172232 21.2509826594 50724.029541233 21.1800681832 50981