М. М. Кутепова The World of Chemistry Мир

According to the passage, what does it mainly describe?

1. 
   theories to explain the na- c) heat of vaporization ture of heat
   
2. 
   expansion due to heat d) temperatures and molecular
   

energy

36. 
    According to the passage, what substance is used in the examples?
    

1. 
   water c) ethanol
   
2. 
   acidic solution d) cobalt (II) cloride
   

36. 
    According to the passage, what is the heat of water vaporization at 100°C?
    

1. 
   331 calories per gram c) 540 calories per gram
   
2. 
   590 calories per gram d) 20 calories per gram
   

36. 
    When steam at 1000°C is condensed to water at the same temperature, how many calories of heat are liberated?
    

1. 
   300 c) 540
   
2. 
   331 d) 100
   

98

36. 
    According to the passage, what does the process of vaporization require?
    

1. 
   the addition of steam to the c) the addition of heat to the liquid liquid
   
2. 
   the increase of temperature d) the decrease of temperature
   

36. 
    What might be the possible title to the text?
    

1. 
   Heat Is a Form of Energy c) Heat of Vaporization
   
2. 
   What Is Heat d) Heat and Temperature
   

At the Paris Exhibition of 1855 aluminium was exhibited for the first time. It was regarded as one of the principal novelties of that year. The new metal was shown as a bar, bearing a very sensational inscription “Silver from Clay”. It was regarded even at that time as the metal of future with great practical possibilities. Scientific and non-scientific press devoted long articles to its description. Special attention was paid to the advantages of aluminium — it is light, it does not rust, and is very strong especially when mixed with other metals.
The first attempts to isolate this metal from its oxide were made by Davy and some years later by Berzelius. But both failed to obtain any satisfactory results. Nearly fifty years had passed before French and German scientists isolated aluminium in 1854. It was isolated by electrolysis. Scientists also investigated the distribution of the metal in nature. Aluminium is one of the mo$t widely distributed of the chemical elements but it is never found in the free state. Metallic aluminium has a beautiful silver lustre, but when impure, aluminium has a grey or a bluish colour. The isolation of aluminium became simple and cheap only when man harnessed electricity. Only then was it possible to produce aluminium and put it to use.

36.