STVDY OF BTDROGfitf. H 



inverted bottles remained filled with water. 

 Measure the length and breadth of the tray of 

 water. How many square inches are there on 

 the surface of the water? If the pressure on 

 each square inch is fifteen pounds, what is the 

 pressure of the atmosphere on the whole sur- 

 face? 



C. When the oxygen was removed from the jar in 

 the nitrogen experiment, why did the water 

 rise? Invert a jar of air and press it down 

 into the water. What is the level of the water 

 within the jar now? Explain. 



5. STUDY OF HYDROGEN. (Dem.) 



Materials : Two small bottles, each fitted with a rubber stopper 

 fn which are two holes, thistle-tube, delivery-tube, tray of water, 

 test-tube, wide-mouth bottle, pieces of zinc, diluted hydrochloric 

 acid, potassium permanganate solution. 



A. Preparation of hydrogen. 



i . Put some small pieces of zinc into the bottle 

 and insert the stopper. Through one 

 hole in the stopper pass the thistle-tube 

 until the lower end nearly touches the 

 bottom of the bottle. Pass one end of 

 the delivery-tube through the second 

 hole and let the other end of the tube 

 dip beneath the water in the tray. Pour 

 into the thistle-tube dilute hydrochloric 

 acid until the lower end of the thistle- 

 tube is covered. 

 a. What do you see within the bottle? 



