New Town Secondary School Intro to Organic Chem_2023

Page 1 New Town Secondary School Secondary 4E Pure Chemistry Name: ( ) Class: Date: Organic Chemistry – Introduction to Organic Chemistry Syllabus At the end of this topic, students should be able to: 11.1a Name natural gas, mainly methane, and petroleum as sources of energy. 11.1b Describe petroleum as a mixture of hydrocarbons and its separation into useful fractions by fractional distillation (see also 1.2(a)). 11.1c Name the following fractions and state their uses (i) petrol (gasoline) as a fuel in cars. (ii) naphtha as the feedstock and main source of hydrocarbons used for the production of a wide range of organic compounds in the petrochemical industry (see also 11.1(d)). (iii) paraffin (kerosene) as a fuel for heating and cooking and for aircraft engines. (iv) diesel as a fuel for diesel engines. (v) lubricating oils as lubricants and as a source of polishes and waxes. (vi) bitumen for making road surfaces. 11.1d Describe the issues relating to the competing uses of oil as an energy source and as a chemical feedstock (see also 11.1(c)(ii)). 11.2a Describe a homologous series as a group of compounds with a general formula, similar chemical properties and showing a gradation in physical properties as a result of increase in the size and mass of the molecules, e.g. melting and boiling points; viscosity; flammability

Page 2 Introduction Before 1828, all organic compounds were obtained from organisms or their remains. The belief then was that the synthesis of organic compounds from inorganic compounds in the laboratory was impossible. Things changed with the synthesis of urea from inorganic substances in 1828. All organic compounds contain carbon atoms, and most of them contain hydrogen atoms as well. The simplest organic compounds made up of carbon and hydrogen atoms only are known as hydrocarbons. Organic compounds may also contain other elements such as oxygen, chlorine and nitrogen. However, not all carbon containing compounds are considered organic compounds (i.e. carbon dioxide, carbon monoxide and carbonate ions) Fuels and Crude Oil Two main types of fuels which are used today to generate energy – fossil and nuclear. These are used as they produce a large amount of heat energy during burning. Examples of fossil fuels which are used as sources of energy are natural gas (mainly methane), coal and petroleum (mixture of hydrocarbons with different boiling points). Petroleum Since petroleum is a mixture of hydrocarbons with different boiling points, the unrefined petroleum (crude oil) is first sepatated into different fractions by fractional distillation.

Page 3 Issues Relating to Competing Uses for Oil As petroleum is a non-renewable energy source, global supplies will eventually run out. Because there are competing uses for oil, oil as a resource gets depleted in a shorter time. Using oil as a chemical feedstock in industries also leads to air and water pollution. To reduce reliance on oil, co