From Atoms to Materials

methane (CH 4 ) ethane (C 2 H 6 ) propane (C 3 H 8 ) butane (C 4 H 10 ) Language tip molecule noun ; molecular adj . Extension large small molecular size boiling point low high larger size smaller size ol cular siz boiling point lower boiling point higher boiling point Language tip viscous adj .; viscosity noun ; volatile adj .; volatility noun viscosity 黏稠度 volatility 揮發性 Besides boiling point, other physical properties of hydrocarbons are also generally related to their molecular size, as listed below. Fig. 13.30 Variations in some physical properties of hydrocarbons of different molecular sizes Physical properties of hydrocarbons Hydrocarbons of different molecular sizes show variations in physical properties. Table 13.10 shows the boiling points of some simple hydrocarbons. In general, the larger a hydrocarbons molecular size, the higher its boiling point. Table 13.10 Boiling points of some simple hydrocarbons Molecular size of hydrocarbon Boiling point −161 °C −88 °C −42 °C −1 °C increasing molecular size increasing boiling point light deep colour large small molecular size low high boiling point viscosity* low high high low volatility* 82 © United Prime Educational Publishing (HK) Limited 2024 All rights reserved; no part of this publication may be reproduced, photocopied, recorded or otherwise, without the prior written permission of the Publisher. Sample