Chemical lecture experiments . le. The siphon is started by gentle suctionwith the mouth on the longer arm, and, when the gas hasfilled the tube, the lower end is thrust into the empty cylin-der. However, as the uppe* cylinder is fixed, it is betterto arrange to have the lower cylinder brought up frombeneath. The presence of the gas in the longer arm of thesiphon will be known by the taste. After a few minutesthe gas will all have left the upper cylinder, and a candlewill continue to burn when lowered into it, while if alighted candle is inserted in the lower cylinder, it will beextinguished.
Chemical lecture experiments . le. The siphon is started by gentle suctionwith the mouth on the longer arm, and, when the gas hasfilled the tube, the lower end is thrust into the empty cylin-der. However, as the uppe* cylinder is fixed, it is betterto arrange to have the lower cylinder brought up frombeneath. The presence of the gas in the longer arm of thesiphon will be known by the taste. After a few minutesthe gas will all have left the upper cylinder, and a candlewill continue to burn when lowered into it, while if alighted candle is inserted in the lower cylinder, it will beextinguished. Two 2 1. cylinders ; siphon ; C02 supply ; candle on wire. 38. Carbon dioxide extinguishes the flame of a candle. —That carbon dioxide is heavier than air and is a non-sup-porter of combustion is interestingly shown by pouring 2 the gas down into a wooden or metal trough in whichfive small candles are burning. As the carbon dioxide flowsdown the trough, the candles are extinguished in rapidsuccession. CAKBON DIOXIDE 315. Fig. 126 The trough may be made by bending a piece of tin 1 or by tacking two pieces of wood together at rightangles. The trough should be in-clined at an angle of 45°, and thecandles so attached as to burn inan upright position. To preventan upward current of air, it isbest to cut off the lower part of thetrough by means of a block ofwood or a piece of cardboard (). The candles should be ofthe smallest size and are placed approximately 15 Trough (Fig. 126); small candles ; 2 1. beaker of C02. 39. Carbon dioxide in expired air extinguishes a candleflame. — Air from the lungs is collected in a cylinder overwater. By taking the last portion of one exhalation, that is,that which has had the longer sojourn in the lungs, a gasquite rich in carbonic acid is obtained, and, indeed, theper cent of this gas will be so great as to cause the flame ofa candle, when it is lowered into the cylinder, to be extin-guished. By using a flexible ru
Size: 1713px × 1459px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectchemist, bookyear1901
