| Device for demonstration the expansion of gases from heating 1. Take a glass tube length of 350-400 mm and a diameter of 5-6 mm. At a distance of 50 - 60 mm from the end of the tube to bend at right angles by heating, then pick up the cork that seals to the neck of the flask or bottle. The short end of the tube pass through the tube, and a long set horizontally and attach it to scale. Then the tube with a cork is removed from the flask and its horizontal part is introduced slightly tinted water, after which the flask was again stoppered. If we now heat the flask with your hands or drop into heated water, the air in the flask will expand, as can be seen on the movement of the liquid column. 2. Glass tube length of 350-400 mm is passed through the tube, covering the flask so that the lower end of the tube by 3-4 mm did not reach the bottom of the flask. Pulling out the cork with a glass tube, the flask is poured tinted water at half the volume of the bulb, again dipped into the tube water and sucked in his breath. Water in the tube rises. It is necessary that its level was slightly higher than cork. Not letting air into the tube, stoppered flask. Using a rubber ring mark the initial water level in the tube. When heated retorts even handed height of the liquid column starts to grow rapidly. This indicates an increase in gas pressure when heated. 3. Water fountain. In a flask with a wide neck 500 cm pour 400-420 cm3 tinted water. The flask was closed with a rubber stopper through which two glass tubes are missing. One of them drawn from the end facing up almost touches the bottom of the flask, and another - short - perhaps more removed from the water surface. The tube connecting a rubber hose with a round bottom flask, sealed with a rubber stopper, through which the missing glass tube. When heated on the stove flame air in the flask, round bottom expands, and therefore the pressure in it increases. Increased pressure causes the rise of the liquid through a tube with a drawn ending, with the result that starts to hit the fountain. The device that is always fast to prepare for work? 4. Closed manometer. Right knee manometer by rubber tubing connecting the glass ball or bulb, and the left knee through a rubber hose wear brief glass tube. When heated flask gas expands and the fluid level in his left knee gauge rises gradually. |