8 VETERINARY STATE BOARD 



ing, char. When pure they are completely consumed under con- 

 tinued heat ; any residue remaining after the disappearance of the 

 char indicates the presence of mineral matter. They are the essen- 

 tial compounds of plant and animal structures and their molecular 

 composition may be very complex, but includes only a few elements. 

 An inorganic compound is any one of the large series of com- 

 pounds (minerals, metals, etc.) which are not directly connected 

 with vital processes, either in origin or nature, and which are 

 broadly and relatively contrasted with organic compounds. 



Distinguish between solution and emulsion. 



The term solution is applied to any clear and homogeneous 

 liquid obtained by causing the transformation of matter from a 

 solid or gaseous state to the liquid state, by means of a liquid called 

 the solvent or menstruum. Solutions may be made by uniting two 

 liquids, as when we dissolve oil in ether. 



The term emulsion is used to designate a more or less homo- 

 geneous liquid, rendered opaque or milky by the suspension in it 

 of finely divided particles of fat, oU or resin. 



Distinguish in meaning between the following when used in names of 

 chemical compounds : hypo and per. Give examples to illus- 

 trate the differences. 

 Eypo is prefixed to a compound containing less of the negative 

 element, oxygen, than the ous compound in that series, as hypo- 

 chlorous acid, HCIO, and chlorous acid, HCIO2. 



Per or hyper indicates that the compound contains a greater 

 amount of oxygen than the ic compound in the series, as perchloric 

 acid, HCIO4, and chloric acid, HCIO3. We have the term peroxide, 

 applied to compounds very rich in oxygen. 



Name a substance used as a bleaching powder and explain chemically 

 its bleaching properties. 



Hypochlorite of lime, CaOClj. The element chlorine has a strong 

 affinity for hydrogen. In the presence of moisture, it unites with 

 the hydrogen and thus liberates oxygen, which acts upon the coloring 

 matter and bleaches it. 



Write the equation to show the reaction between (a) sulphuric acid 

 and zinc, (b) hydrochloric acid and calcium carbonate, (c) 

 sodium carbonate and calcium hydroxide. 



(a) H,SO, + Zn = ZnSO, + H,. 



(b) 2HC1 + CaCOg = CaCl^ -f H^O + CO,. 



(c) Na3C03 + Ca(OH), = 2NaOH + CaC03. 



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