Name this compound (IUPC required): 2,dimethylpropane or dimethylpropane (it is clear that both methyl groups are on second carbon atom as only 3 carbon atoms exist in longest chain propane). When asked to a compound, spelling is key. ny spelling errors will result in a loss marks. Give all or position isomers that exist to this isomer: There is only one more position isomer which is 1,3- dichloro-2, dimethylpropane. When identifying isomers that exist, always m so that you don t come up with identical isomers.
display formula 2,dichlorohexane. When asked to draw a display formula, include all hydrogen atoms. Leaving sticks is not acceptable.: Describe essential features fractional distillation crude oil that allow fractions to be separated. HC fractions differ in ir boiling points; boiling points depend on chain length with longer chains having higher boiling points. hort chain hydrocarbons condense near top tower where it is cooler. Focus on principles fractional distillation rar than physical features tower (e.g. bubble caps). These can be included if re are more than 4 marks available for question.
structure a chain isomer but-1-ene. Chain isomer means that carbon skeleton has changed. s but-1-ene is a straight chain molecule, a branch needed to be introduced. Name this molecule: methylpropan-1-ol Remember that spelling counts when you are asked to give IUPC s molecules. methylpropan-3- ol is a common mistake here.
structure a functional group isomer to this molecule: Or Only cyclic alkanes can have same molecular formula as an alkene refore be functional group isomers. This type question is asked fairly regularly in exams. How many structural isomers C 6 H 14 are re? 5: hexane; methylpentane; 3- methylpentane; 2,3- dimethylbutane; 2, dimethylbutane Remember that it is best to use a systematic approach (one branch first, n two branches etc.) each isomer to avoid mistakes.
What is empirical formula? C 3 H 6 Cl Be careful to read question. common mistake with this question is to state molecular formula instead. Name this molecule: 2,3-dichloro-3-methylpentane pelling errors will be penalised when you are asked to compounds. Common errors are to give incorrect numbers, to omit numbers or forget about di to think branch is an ethyl group.
Name this molecule: 2,2,4-trimethylpentane pelling errors will be penalised when you are asked to a molecule. Find longest chain first, n identify position branches. Keep numbers low (2,2,4, not 2,4,4); re are three branches so don t omit tri. lthough re are 8 carbon atoms, longest chain is a pentane, not octane. Give s 5 fractions obtained by fractional distillation crude oil list m in ascending order. Mineral oil (lubricating oil), gas oil (diesel), kerosene (paraffin), naphtha, petrol (gasoline) Make sure you learn s order fractions f by heart.
propene burning in a limited supply air to form a solid water. C 3 H 6 + 1.5O 2 3C + 3H 2 O Make sure you read question carefully. Usually, CO is formed during incomplete combustion, but CO is not a solid. oot, C, is though. how C 3 H 7 H completely combust to form water, carbon dioxide sulfur dioxide. C 3 H 7 H + 6O 2 4H 2 O + O 2 + 3CO 2 The 8 th H atom (bonded to atom) is easily overlooked here.
how nitrogen monoxide is formed from nitrogen oxygen. N 2 + O 2 2NO or ½ N 2 + ½ O 2 NO how NO is removed by a catalytic converter. 2CO + 2NO 2CO 2 + N 2 or 2NO N 2 + O 2 or C + 2NO CO 2 + N 2 Don t make mistake producing NO 2. This is still a pollutant gas.
how carbon monoxide is removed by a catalytic converter. CO + ½ O 2 CO 2 or 2NO + 2CO 2CO 2 + N 2 Common mistakes are to produce N, N 2 O or NO 2 instead N 2 in equation 2. how C 15 H 32 is cracked into two C 4 H 8 a third molecule. C 15 H 32 2C 4 H 8 + C 7 H 16 Make sure your equation is balanced that you have produced alkane(s) ND alkene(s).
Write equations to show how CH 2 Cl 2 is formed from CH 3 Cl Cl 2 in presence UV light. Initiation Cl 2 2Cl. Propagation CH 3 Cl + Cl.. CH 2 Cl + HCl. CH 2 Cl + Cl 2 CH 2 Cl 2 + Cl. Termination. CH 2 Cl + Cl. CH 2 Cl 2 missing radical dot will be penalised once. s will a radical dot in wrong place. how C 22 H 46 is cracked into ene propene in a 3:2 ratio plus one or product. C 22 H 46 3C 2 H 4 + 2C 3 H 6 + C 10 H 22 Make sure your equation is balanced that you have produced alkane(s) ND alkene(s).