NJC 9 Polymer Part 2 Checkpoint

National Junior College SH1 H1 Chemistry 1 Polymers (Part 2) – Reactions of Functional Groups Checkpoint 1 1 Pentane reacts with Cl2(g) in presence of UV light to give three monochlorinated products. Draw the skeletal formula of the three compounds. Cl Cl Cl 1-chloropentane 2-chloropentane 3-chloropentane 2 2-chloropentane reacts with hot ethanolic KOH to give three isomeric products with molecular formula of C5H10, containing a pair of cis-trans isomers. Identify the type of reaction and deduce the structure of the three products. Elimination reaction pent-1-ene trans pent-2-ene trans pent-2-ene 3 Propene is converted to propan-1,2-diol in a 2-step reaction sequence. Fill in the reagents and conditions required for each step as well as the missing structure. Step 1 OH OHStep 2 Br2 in CCl4 NaOH(aq), heat Br Br

National Junior College SH1 H1 Chemistry 2 Checkpoint 2 1 Butan-2-ol undergo elimination to gives 2 different alkenes. Draw the structures of the 2 alkenes. 2 Propan-1-ol is converted to propane in a 2-step reaction sequence. Fill in the reagents and conditions required for each step as well as the missing structure. OH Step 1 Step 2 Excess conc H2SO4, heat Or Al2O3(s), heat H2(g), Pt(s) or H2(s), Ni(s), heat

National Junior College SH1 H1 Chemistry 3 Checkpoint 3 1 Fill in the blanks provided. Indicate the reagent and condition required for the reaction and the observation of the reaction. (a) Reagent and Condition: K2Cr2O7, H2SO4(aq), heat OR KMnO4, H2SO4(aq), heat (b) CH3CH(OH)CH3 [O]+ C O CH3 OH2+ H3C 2 Which alcohol does not result in a colour change when warmed with acidified potassium dichromate(VI)? A B Tertiary alcohol cannot be oxidized C D 3 Draw the structure of the alcohol with the molecular formula C 5H12O that is resistant to oxidation. Give the name of this alcohol. C CH2CH3H3C CH3 OH 2-methylbutan-2-ol 2

National Junior College SH1 H1 Chemistry 4 Checkpoint 4 Fill in the blanks provided. Place a ‘ ✓’ next to the reducing agent which allows the reduction to be carried out. CH3 C O H + [H] CH3 C OH H H  LiAlH4 in dry ether  NaBH4 in ethanol  H2/Pt  LiAlH4 in dry ether  NaBH4 in ethanol  H2/Pt  LiAlH4 in dry ether  NaBH4 in ethanol  H2/Pt + [H]O OH  LiAlH4 in dry ether  NaBH4 in ethanol  H2/Pt + [H]O OH  LiAlH4 in dry ether  NaBH4 in ethanol  H2/Pt Checkpoint 5 CH3CH2CHO KMnO4, dil H2SO4 heat K2Cr2O7, dil H2SO4 heat O OH ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ 2 2 2 4 2 O H C8H8O CH3CH2COOH

National Junior College SH1 H1 Chemistry 5 Checkpoint 6 CH3CH2COOH conc H2SO4 heat+ CH3OH conc H2SO4 heat O O + H2O DCC CH3COOH + NH3 DCC O N + H2O C OCH2CH2CH2 O HHO C4H8O3 C OCH3CH2 O CH3 + H2O C N O H H H3C + H2O O OH N H +

National Junior College SH1 H1 Chemistry 6 Checkpoint 7 Draw the structure of the following esters. C CC H H O O CH3 H H H C CC H H O O CH2CH3 H H H Methyl propanoate Ethyl propanoate Checkpoint 8 Write the balanced equation when propyl ethanoate reacts with (i) H2SO4(aq), heat C CH H H O O CH2CH2CH3 CH3COOH + HOCH2CH2CH3+ H2O (ii) NaOH(aq), heat C CH H H O O CH2CH2CH3 CH3COO- + HOCH2CH2CH3+ OH-

National Junior College SH1 H1 Chemistry 7 Checkpoint 9 Draw the structure of the products formed when the amide A reacts with N O Amide A (i) H2SO4(aq), heat O OH N H H+ (ii) NaOH(aq), heat O O- N H