Page 1 



1919 



CHEMISTRY 



Monday, September 15 2-5 p.m. 



Answer ten questions as indicated below. <||2^ 



Attach to the answer, in each case, the number and letter used in the printed paper. 



Part I 

 (Answer all questions in Part I.) 



1. a) Distinguish between a chemical law and a chemical theory. 



b) Name three laws dealing with weights; three dealing with gases. 



c) Name two important theories in chemistry. 



2. Discuss sulphuric acid with reference to: 



a) Its physical and chemical properties. 



b) Four of its important uses. 



c) One process of manufacture. 



3. Write equations for the following reactions, using formulas throughout. The 



equations must be properly balanced to receive credit: 



a) Ethyl alcohol burned completely in oxygen = 



b) Hydrogen sulphide+ chlorine (in solution) = 



c) Silver nitrate+ calcium chloride = 



d) Nitric oxide-f oxygen gas= 



e) Ferric chloride + sulphuric acid (concentrated) = 



4. a) How many cubic centimeters of carbon dioxide, CO2, measured at 0° and 



760 mm., will be absorbed by a solution containing 2 grams of sodium 

 hydroxide, to form sodium carbonate and water? (Na 23, O 16, 

 C 12, H 1.) 



Note. — One liter of carbon dioxide at 0°C. and 760 mm. weighs 1 .98 grams. 



b) The formula of a gaseous compound is C2H2. Calculate its percentage 

 composition and its vapor density. 



5. a) Why does wood burn with a flame while charcoal merely glows ? 



b) Can you light a jet of o.xygen in an atmosphere of (1) air, (2) hydrogen ? 



Explain. 



c) Describe and explain the successive effects observed when a thin strip of 



copper is passed very slowly through a Bunsen flame. 



(THIS EXAMINATION IS CONTINUED ON PAGE 2) 



54 



