1918 



Comprehensive Examination 



CHEMISTRY 



Monday, September 16 2-5 p.m. 



A teacher's certificate covering laboratory instruction must be presented as a part 

 of the examination unless the laboratory notebook is to be presented at a laboratory 

 examination. 



Answer ten questions as indicated below. 



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. Define, and also illustrate by means of at least one example in each case, the 



following terms: (a) element; {b) synthesis; (c) cation; {d) catalyzer; 

 {e) hydrolysis. 



2. Write equations for any five of the following reactions, using formulas through- 



out: (The equations must be properly balanced to receive credit.) 



a) Iron and dilute sulphuric acid= ? 



b) Lead acetate and hydrochloric acid = ? 



c) Aluminium hydroxide and sulphuric acid= ? 



d) Ferrous chloride and chlorine water = ? 



e) Copper sulphate and barium hydroxide = ? 



/) Manganese dioxide and concentrated hydrochloric acid = ? 



3. 10 grams of crystallized ammonium carbonate, (NH4)2 C03'H20, are heated 



until completely decomposed into ammonia, carbon dioxide, and steam. 

 What will be the total volume of these products at 273° C. and 760 mm. 

 pressure? (0 = 1G, N = 14, C = 12, H=l.) 



Note — Under the conditions above, liter volumes of ammonia, carbon dioxide, and steam 

 weigh . 38 gram, . 98 gram, and . 40 gram, respectively. 



4. State Avogadro's law and show in detail how this law guides the chemist in 



determining the molecular weights of gases or vapors. 



5. a) Name and describe one important commercial process for manufacturing 



sodium carbonate, giving all the equations involved. 

 b) How may sodium acid carbonate be distinguished from sodium carbonate ? 



Part II 

 {Answer five questions from Part II. Extra questions will receive no credit.) 



6. Two grams of finely divided metallic nickel are heated with a quantity of 



sulphur slightly in excess of that needed for complete combination until 

 the chemical action is completed and the excess of sulphur is vaporized. 

 The weight of the product formed is 3.09 grams. Give Uie name of the 

 product, find its percentage composition and also the simplest formula by 

 which its composition may be expressed. (Ni = 58.7, S=32.) 



(SEE NEXT PAGE) 

 B 49 



