EXERCISES
1. How could you distinguish between oxygen, hydrogen, and nitrogen?
2. Calculate the relative weights of nitrogen and oxygen; of nitrogen and hydrogen.
3. In the preparation of nitrogen from the air, how would hydrogen do as a substance for the removal of the oxygen?
4. What weight of nitrogen can be obtained from 10 l. of air measured under the conditions of temperature and pressure which prevail in your laboratory?
5. How many grams of ammonium nitrite are necessary in the preparation of 20 l. of nitrogen measured over water under the conditions of temperature and pressure which prevail in your laboratory?
6. If 10 l. of air, measured under standard conditions, is passed over 100 g. of hot copper, how much will the copper gain in weight?
WILLIAM RAMSAY (Scotch) (1855-)
Has made many studies in the physical properties of substances; discovered helium; together with Lord Rayleigh and others he discovered argon, krypton, xenon, and neon; has contributed largely to the knowledge of radio-active substances, showing that radium gradually gives rise to helium; professor at University College, London