Revision exercises

Ex.1. Answer the following questions:

1. What does organic chemistry study? 2. What did Wöhler discover in 1828? 3. Why can carbon form molecules that contain an infinite number of C atoms? 4. What is a functional group? 4. What are the physical properties of an organic substance? 5. What are polymers? 6. Are there many of carbon compounds in the world? 7 What is the carbon cycle? . 8. Why are organic compounds worth being studied? 9. Why are organic chemists generally employed by different industries related to chemistry? 10. Is organic chemistry the most important branch of chemistry?

Ex.2. Match the words with their definitions:

1. DDT	a. mysterious, metaphysical energies that inhabit “organic” matter and which keep organisms alive and functional;
2. gasoline	b. to join with each other, to become firmly fixed together;
3. variety	c. a substance containing atoms from two or more elements;
4. bond	d. a chemical used to kill insects that harm crops;
5. regardless	e. one of the substances that combine to form proteins;
6. amino acids	f. a liquid obtained from petroleum, used mainly for producing power in the engines of cars, trucks;
7. exploration	g. the act of travelling through a place in order to find out about it or find something such as oil or gold in it;
8. vital forces	h. without being affected or influenced by something;
9. pulp	i. a lot of things of the same type that are different from each other in some way;
10. compound	j. a very soft substance that is almost liquid, made by crushing plants, wood, vegetables etc.

Ex.3. Say whether the following statements are true or false:

1. In the 17th century it was believed that the organic compounds cannot be synthesized in the laboratory. 2. Carbon compounds don’t have any mineral origin. 3. Wöhler showed that nearly all compounds of plant origin are composed of carbon, hydrogen and oxygen. 4. Carbon can form molecules that contain an infinite number of C atoms. 5. Carbon atom’s bonds form a pyramid with a spike at the top. 6. Functional groups are used to determine the molecular weight of the compound. 7. Study of organic chemistry is important because organic compounds are very rare and unique and can hardly be found anywhere. 8. Carbohydrates and fats are sources of energy for all living systems. 9. Biotechnology is used in production of biodegradable plastics, vegetable oil, biofuels. 10. Organic chemists at all levels are generally employed by pharmaceutical, biotechnical, chemical, consumer product, and petroleum industries.

Ex.4. Insert the necessary word:

1. The vast majority of organic compounds are typically chains or rings of … that contain other elements such as O, N, P, S, Cl, Br and I. 2. There are over five million of these compounds known today and an almost … of new compounds could possibly be synthesized. 3. This can be compared to the total number of …, which is approximately half a million. 4. Carbon has the ability to bond with itself to form long chains and … . 5. It can form molecules that … from one to an infinite number of C atoms. 6. The number of different design possibilities for organic molecules is … . 7. In order to enable classification of such a large number of molecules, organic chemists have employed the principle of classifying all organic compounds into families according to their … . 8. This greatly simplifies the study of … as molecules with the same functional groups behave the same in most chemical reactions. (infinite number, ring structures, carbon atoms, endless, contain, inorganic compounds, functional groups, organic compounds)