HCI Post Promo Quiz 1 to 3 with ANS

Hwa Chong Institution C1 H2 Chemistry Post-Promo Quiz 1 Name: …………………………………………… Class: 12S………..… Time: 20 min Circle true/false for each statement. For each false statement, briefly comment what is wrong. Ta ke this quiz seriously as it serv es as a chec k on how well you have understood some of the concepts covered in C1. For those who get below 1 2 ma r k s , y o u p ro b a b l y h av e to fi n d ti me t o grasp, consolidate and linkup the concepts. It is always good to start early! 1 2 NaOH (aq) + Cl2 (aq) o NaCl (aq) + NaClO( a q ) The above is an example of a disproportionation reaction. True / False .......................................................................................................................... 2 The electronic configuration of Cr in chromium peroxide Cr2(O2)2 is [Ar] 3d4. True / False .......................................................................................................................... 3 The Be3Cl6 trimer is a simple covalent molecule containing four co-ordinate bonds. True / False .......................................................................................................................... 4 The geometry and shape of SbF 5 2 is octahedral and square pyramidal respectively. True / False .......................................................................................................................... 5 The 'Hc of but-1-ene and ethene are p and q kJ mol–1 respectively. Thus, the 'Hr of 2C2H4(g) Æ C4H8(g) is 2q – p kJ mol–1. True / False .......................................................................................................................... 6 The following shows step II of a reaction which consists of three steps: II N 2O2 + H2 H2O + N2O (slow) The reaction is first order with respect to both N2O2 and H2. True / False .......................................................................................................................... 7 For an overall zero order reaction, the sketch of rate vs time yields a straight line as changing the concentration of the reactants does not affect the rate. True / False .......................................................................................................................... 8 MgCl2 deviates from ideality as it forms strong ionic bonds. True / False .......................................................................................................................... 15 www.KiasuExamPaper.com 1

9 When temperature changes, the position of the equilibrium alway s shifts either to the left or right depending on the 'G. True / False .......................................................................................................................... 10 When 15 cm 3 of a gaseous hydrocarbon X w e r e b u r n e d i n 1 0 0 c m3 of oxygen, the final gaseous mixture contained 60 cm 3 of carbon dioxide and 10 cm3 of unreacted oxygen. The formula of hydrocarbon X is C4H8. True / False .......................................................................................................................... 11 The lattice energy of silicon dioxide is: Si4+ (aq) + 2O2 (aq) o SiO2 (s) True / False .......................................................................................................................... 12 HO The addition of HBr (l) to the above molecule will result in it having less than 6 stereogenic centres. True / False .......................................................................................................................... 13 Acidified KMnO4 is used as an oxidizing agent for alkenes. HC l (aq) can be used to acidify KMnO4. True / False .......................................................................................................................... 14 When propene reacts with a mixture of Br 2 in conc NaC l, the following molecule might be produced: H3CC C H H Br H Br True / False .......................................................................................................................... 15 The homolytic fission of CHFClCF2Cl by UV radiation would likely result in the formation of •CFClCF2Cl. True / False .......................................................................................................................... ~~~~~~~~~ End of Quiz ~~~~~~~~~ Post Quiz Reflection: This is my best, I have reached my limit! I can do much better than this! I have yet to unleash my potential! www.KiasuExamPaper.com 2

Hwa Chong Institution C1 H2 Chemistry Post-Promo Quiz 1 Name: …………………………………………… Class: 12S………..… Time: 20 min Circle true/false for each statement. For each false statement, briefly comment what is wrong. Ta ke this quiz seriously as it serv es as a chec k on how well you have understood some of the concepts covered in C1. For those who get below 1 2 ma r k s , y o u p ro b a b l y h av e to fi n d ti me t o grasp, consolidate and linkup the concepts. It is always good to start early! 1 2 NaOH (aq) + Cl2 (aq) o NaCl (aq) + NaClO( a q ) The above is an example of a disproportionation reaction. True / False Cl is reduced (O to 1 in NaCl) and oxidised (O to +1 in NaClO) at the same time. 2 The electronic configuration of Cr in chromium peroxide Cr2(O2)2 is [Ar] 3d4. True / False CrO2. Cr has oxidation state of +2. 3 The Be3Cl6 trimer is a simple covalent molecule containing four co-ordinate bonds. True / False It consists of 3 BeCl2 monomers. 4 The geometry and shape of SbF 5 2 is octahedral and square pyramidal respectively. True / False It forms a 6 co-ordinate geometry. 5 The 'Hc of but-1-ene and ethene are p and q kJ mol–1 respectively. Thus, the 'Hr of 2 C2H4(g) Æ C4H8(g) is 2q – p kJ mol–1. True / False .......................................................................................................................... 6 The following shows step II of a reaction which consists of three steps: II N 2O2 + H2 H2O + N2O (slow) The reaction is first order with respect to both N2O2 and H2. True / False H2 might be an intermediate which can't appear in the rate equation. 7 For an overall zero order reaction, the sketch of rate vs time yields a straight line as changing the concentration of the reactants does not affect the rate. True /F a l s e 8 MgCl2 deviates from ideality as it forms strong ionic bonds. True / False MgCl2 is a solid. No relation to ideal gas. 15 ANSWERS www.KiasuExamPaper.com 3 NaOH (aq) + C l 2 (aq) o NaC l (aq) + NaC l O (aq) The above is an example of a disproportionation reaction. True / Cl is reduced (O to 1 in NaC l) and oxidised (O to +1 in Na ClCl O)O) aat t ththe same time. The electronic configuration of Cr in chromium peroxide Crrrrrr 2222222222222222222 (O(O(O(O(O(O(O(O(O(OOO(O(O(O(O(O(O(O(O(OOOO(( 222222222222222222 ))))))))))))))))))))) 22222222222222222222 iiiiisisiiiiiiiis [Ar] 3d 44 . True / CrO 2 . Cr has oxidation state of +2. The Be 3 C l 6 trimer is a simple covaaaaaleleeeelel ntntntntntnt mmmmoolooooo ececcccccule contnnnnn aaaiaaaaaaaaa n ing four coo -- ororddinaatete onds. True / t consists of 3 BeCl 2 momomoomommm nonnonononnomers. The geometryyyyyy aaaaandndndndnnnd s h apepepepepepepep ooooooffff fff SbSbSbSbSbbS FFFFFFF 5555555 2222222

iiis o ctctctctctcc ahahahahahhahedeedededeedraaaaaaalll and square pyramidal espectively. True / t formsssssssssssss aaaaaaa 666666 ccccoooooooo ----- oroooooo dinaaaaaaatetetettt gggggggeeeoee meemeeemem trtrtrtrtrtrtry.y.y.y.yyy T he ' H c o f fffff bubububububuuttttttt - 1 - ene annnnnnnddd etetetetetetethehehehehehehenenenenenee are p and q kJ mol – 1 respectively. Thus, t he ' HHHH rr ooooo ffffff 2 2 2 2222 CCCCCCC 22222 HHHHHHH 444 (g(g(g(ggg) ) ) )))) ÆÆÆÆÆÆÆ C 4 H 8 (g) is 2 q – q p kJ mol –1 . True / ............................. ...... ..... .....................................