Section B Bahagian B [20 marks] [20 markah] Answer any one questions from this section. Jawab mana-mana satu soalan daripada bahagian ini. 1. (a) Diagram below shows the structural formulae of four organic compounds. Rajah di bawah menunjukkan formula struktur empat sebatian-sebatian organik. Diagram/Rajah Based on the structural formulae shown above, state the homologous series and functional group for each of the organic compounds. Berdasarkan formula struktur di atas, nyatakan siri homolog dan kumpulan berfungsi bagi setiap sebatian organik yang ditunjukkan. [4 marks/4 markah] (b) Compound S is found to undergo addition reactions. State three addition reactions of compound S and give one example of each reaction. Sebatian S didapati mengalami tindak balas penambahan. Nyatakan tiga tindak balas penambahan bagi sebatian S dan berikan satu contoh bagi setiap tindak balas. [9 marks/9 markah] (c) State two industrial processes that can be used to produce compound R. Nyatakan dua proses industri yang boleh digunakan untuk menghasilkan sebatian R. [4 marks/4 markah] (d) State the materials needed for the preparation of compound Q and write a balanced equation for the reaction. Nyatakan bahan yang diperlukan untuk penyediaan sebatian Q and tuliskan persamaan seimbang bagi tindak balas. [3 marks/3 markah]
2. (a) The table below shows some information on compound X. Jadual di bawah menunjukkan maklumat tentang sebatian X. TABLE/JADUAL Based on the information, Berdasarkan maklumat tersebut, i. determine the molecular formula of compound X. tentukan formula molekul bagi sebatian X. ii. draw the structural formula of X. lukis formula struktur X. [Relative atomic mass: H, 1; C, 12; O, 16] [Jisim atom relatif: H, 1; C, 12; O, 16] [5 marks/5 markah] (b) By referring to suitable examples, explain what is meant by homologous series. Merujuk contoh-contoh yang sesuai, terangkan apakah yang dimaksudkan dengan siri homolog. [5 marks/5 markah] (c) The diagram below shows that an alcohol can be converted to an alkene through dehydration. Rajah di bawah menunjukkan suatu alkohol boleh ditukarkan kepada suatu alkena melalui pendehidratan. DIAGRAM/RAJAH Name an alcohol and describe a laboratory experiment to derive an alkene from the alcohol. Your explanation must including the following: Namakan satu contoh alkohol dan terangkan satu eksperimen di makmal untuk mendapatkan alkena dari satu alkohol. Penerangan kamu mesti mengandungi perkara berikut:
Procedures of the experiments Prosedur eksperimen A labelled diagram showing the apparatus set-up Rajah berlabel menunjukkan susunan radas The equation for the reaction Persamaan bagi tindak balas [10 marks/10 markah] Answer Scheme Chapter 2 Form 5 Paper 2 1. (a) P = Carboxylic acids/carboxyl group Asid karboksilik/kumpulan karboksil [1m] Q = Esters/Carboxylate group Ester/kumpulan karboksilat [1m] R = Alcohols/hydroxyl group Alkohol/kumpulan hidroksil [1m] S = Alkenes/Double bond Alkena/ikatan ganda dua [1m] (b) 1. Reaction with hydrogen Tindak balas dengan hidrogen [1m] Compound S reacts with hydrogen to form saturated hydrocarbon Sebatian S bertindakbalas dengan hidrogen membentuk hidrokarbon tepu [1m] CH 2 = CH 2 + H-H CH 3 CH 3 [1m] 2. Reaction with halogens: Tindak balas dengan halogen: [1m] Compound S reacts with halogen to form saturated organic product Sebatian S bertindakbalas dengan halogen membentuk sebatian organik tepu [1m] CH 2 = CH 2 + Br-Br CH 2 Br CH 2 Br [1m] 3. Reaction with hydrogen halides Tindak balas dengan hidrogen halida [1m] Compound S reacts with hydrogen halide to form saturated organic product Sebatian S bertindakbalas dengan hidrogen halida membentuk sebatian organik tepu [1m] CH 2 = CH 2 + H-Br CH 3 CH 2 Br [1m] (c) 1. Hydration of ethane/penghidratan etena [2m] 2. Fermentation of sugar/fermentasi gula [2m] (d) Materials/Bahan
Methanol, methanoic acid and concentrated sulphuric acid Metanol, asid metanoik dan asid sulfurik pekat [2m] CH 3 OH + HCOOH HCOOCH 3 + H 2 O [1m] 2.(a) i. Empirical formula of compound X = CH 2 Formula empirikal sebatian X Relative molecular mass of compound Jisim molekul relatif sebatian X = (CH 2 ) n = 56 n = 4 [1m] ii. Molecular formula of compound X = C 4 H 8 Formula molekul sebatian X X = (CH 2 ) n = 56 n = 4 = C 4 H 8 [1m] (b) A group of organic compounds which have a same general formula Satu kumpulan sebatian organik yang mempunyai formula am yang sama [1m] Ethene, C 2 H 4 and propene, C 3 H 6 are alkenes. Etena, C 2 H 4 and propena, C 3 H 6 adalah alkena [1m] They have C n H 2n as their general formula Mereka mempunyai C n H 2n sebagai formula am [1m] They have similar chemical properties. Mereka mempunyai sifat kimia yang serupa. [1m]
Both of them undergo hydrogenation process. Kedua-dua mereka mengalami proses penghidrogenan [1m] Their physical properties gradually change Sifat fizik mereka berubah beransur-ansur [1m] Both of them has low boiling point but boiling point of propene is higher than ethene. Kedua-dua mempunyai takat didih rendah tetapi propena mempunyai takat didih yang lebih tinggi daripada etena. [1m] (c) Ethene gas can derives from ethanol. Gas etena boleh didapati dari etanol. [1m] Glass cotton is immerged in ethanol, and then it is placed in the boiling tube. Kapas kaca direndam dalam etanol dan kemudian diletak dalam tabung didih. [1m] Porcelain chips are placed in the boiling tube as shown in the diagram. Serpihan porselin diletakkan dalam tabung didih seperti ditunjukkan dalam rajah [1m] The porcelain chips are as dehydration agent to absorb water from ethanol. Serpihan porselin sebagai agen penghidratan untuk menyerap air daripada etanol. [1m] The broken pots are strongly heated. Serpihan porselin dipanas kan dengan kuat. [1m] then the glass cotton with ethanol is warmed. kemudian kapas kaca dengan etanol dihangatkan. [1m] The gas liberated is collect under water displacement method. Gas terbebas dikutip bawah cara penyesaran air. [1m] equation/persamaan: C 2 H 5 OH C 2 H 4 + H 2 O ethanol ethene etanol etena [1m]