Chemistry_Grade_10-12 (1).pdf

Step 6 combine the elements of the compounds name

Info icon This preview shows pages 176–178. Sign up to view the full content.

View Full Document Right Arrow Icon
Step 6 : Combine the elements of the compound’s name into a single word in the order of branched groups; prefix; name ending according to the functional group. The compound’s name is 2,3-dimethyl-butane . Worked Example 41: Naming the alkanes Question: Give the IUPAC name for the following compound: C H CH 3 H C H H C C H CH 2 CH 3 H H H Answer Step 1 : Identify the functional group The compound is an alkane and will have the suffix -ane. Step 2 : Find the longest carbon chain and number the carbons in the longest chain. There are five carbons in the longest chain if they are numbered as shown below. The prefix for the compound is -pent. C (1) H CH 3 H C (2) H H C (3) C H CH 2(4) CH 3(5) H H H Step 3 : Look for any branched groups, name them and give their position on the carbon chain There are two methyl groups attached to the main chain. The first one is attached to the first carbon atom and the second methyl group is attached to the third carbon atom. Step 4 : Combine the elements of the compound’s name into a single word in the order of branched groups; prefix; name ending according to the functional group. The compound’s name is 1,3-dimethyl-pentane . 162
Image of page 176

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
CHAPTER 9. ORGANIC MOLECULES - GRADE 12 9.7 Exercise: Naming the alkanes 1. Give the structural formula for each of the following: (a) Octane (b) CH 3 CH 2 CH 3 (c) CH 3 CH(CH 3 )CH 3 (d) 3-ethyl-pentane 2. Give the IUPAC name for each of the following organic compounds. (a) H C H H C H H C CH 3 H H (b) CH 3 CH 2 CH(CH 3 )CH 2 CH 3 (c) CH 3 CH(CH 3 )CH 2 CH(CH 3 )CH 3 9.7.3 Properties of the alkanes We have already mentioned that the alkanes are relatively unreactive because of their stable C-C and C-H bonds. The boiling point and melting point of these molecules is determined by their molecular structure, and their surface area. The more carbon atoms there are in an alkane, the greater the surface area and therefore the higher the boiling point. The melting point also increases as the number of carbon atoms in the molecule increases. This can be seen in the data in table 9.3. Formula Name Melting point ( 0 C) Boiling point ( 0 C) Phase at room temperature CH 4 methane -183 -162 gas C 2 H 6 ethane -182 -88 gas C 3 H 8 propane -187 -45 gas C 4 H 10 butane -138 -0.5 gas C 5 H 12 pentane -130 36 liquid C 6 H 14 hexane -95 69 liquid C 17 H 36 heptadecane 22 302 solid Table 9.3: Properties of some of the alkanes You will also notice that, when the molecular mass of the alkanes is low (i.e. there are few carbon atoms), the organic compounds are gases because the intermolecular forces are weak. As the number of carbon atoms and the molecular mass increases, the compounds are more likely to be liquids or solids because the intermolecular forces are stronger. 9.7.4 Reactions of the alkanes There are three types of reactions that can occur in saturated compounds such as the alkanes.
Image of page 177
Image of page 178
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern