102 



AGRICULTURAL CHEMISTRY 



be performed under the hood). Arrange the apparatus as 

 shown in Fig. 44. The delivery tube and cork should fit tightly, 

 and the delivery tube should pass into a test-tube containing 10 cc. 

 of Pb(NO 3 ) 2 solution. Test-tubes containing 10 cc. 

 respectively of NaCl, and CuSO 4 solutions should 

 be conveniently at hand. Place 5 grams of pul- 

 verized FeS in the generating test-tube, add 10 cc. 

 dilute HC1, and immediately connect with the de- 

 livery tube. After the gas has passed through the 

 lead nitrate solution, for a couple of minutes, pass 

 it through the sodium chlorid and copper sulfate 

 solutions ; then allow a little of the gas to escape 

 into a cylinder containing water. Do not allow 

 the free gas to escape in the room. With NaCl no 

 insoluble sulfid is formed. 



Questions. ( i ) What is the odor of the gas ? (2) 

 Write the equation for its production. (3) What 

 was formed when the gas was passed into Pb(NO 3 ) 2 ? 

 Write the reaction. (4) What was formed when 

 the gas was passed through Cu(NO 3 ) 2 ? Write the 

 reaction. (5) Is H 2 S soluble in water ? (6) When albumin decays, 

 from what is the H 2 S produced? (7) Why was no precipitate 

 formed when the gas was passed through NaCl ? 



Problem /. How much H 2 SO 4 can be made from one ton of sul- 

 fur? 



Problem 2. What per cent, of H 2 SO 4 is SO 3 ? 

 Problem j. How much H 2 SO 4 is required to neutralize 500 

 pounds NaOH ? 



Fig. 44. Hydro- 

 gen sulfid gen- 

 erator. 



