RI Chemical Bonding I Remedial

Name: ………………………………………. ( ) Class: ……………. Date: ……………. Raffles Institution Year 5 H2 Chemistry 2024 ChemFocus T3W5 – Chemical Bonding 1 Notes:  Pre-ChemFocus Activity  • Rewatch lecture video on how to draw dot-and-cross for molecules IVY > C2025 – H2 CHEMISTRY (FOR LECTURES) > 4.3 (Dot-&-cross Diagrams of Simple Covalent Molecules) • Watch the online Info-pack video IVY > C2025 – H2 CHEMISTRY > Pages > [ChemFocus] T3W5 Chemical Bonding > First video ONLY

Self-Check Questions 1. Complete the following table. Substances Structure Bonding affecting melting/boiling point ICl MnSO4 BH3 NaBrO3 CH3OH 2. Complete the following table. molecule dot-and-cross diagram shape of molecule structure (include lone pair of e– on central atom) Check the boxes with (✓/⨉) to check for polarity Predominant intermolecular interactions NH3 trigonal pyramidal H N H H ☑ polar bond present ☑ net dipole moment polar / non-polar ☑ polar molecule ☑ H bonded to FON ☑ lp of e– on FON id-id / pd-pd / H-bond CO2 ☐ polar bond present ☐ net dipole moment polar / non-polar ☐ polar molecule ☐ H bonded to FON ☐ lp of e– on FON id-id / pd-pd / H-bond H2O ☐ polar bond present ☐ net dipole moment polar / non-polar ☐ polar molecule ☐ H bonded to FON ☐ lp of e– on FON id-id / pd-pd / H-bond SO2 ☐ polar bond present ☐ net dipole moment polar / non-polar ☐ polar molecule ☐ H bonded to FON ☐ lp of e– on FON id-id / pd-pd / H-bond Learning point(s): Check your answers at IVY > C2025 – H2 CHEMISTRY > Pages > [ChemFocus] T3WX Chemical Bonding > Remaining videos

3. Draw a dot-and-cross diagram to illustrate the electron arrangement in the following substances. 1. CO32– 2. ICl2+ Learning point(s): Learning point(s): 4. In terms of structure and bonding, explain why the melting point of MgO is higher than that of SO 2. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. Learning point(s): 5. In terms of structure and bonding, explain why the boiling point of carbon dioxide is lower than that of ethanol. CC O ethanol C O O carbon dioxide H H H H H H ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. Learning point(s):

Tutorial Discussion Questions (to complete before Chemfocus session) 1a Draw a dot -and-cross diagram to illustrate the electron arrangement in the following substances. [3] (1) O3 Learning point(s): (2) ClO2+ Learning point(s): (3) NO3– Learning point(s): 2a The structures of the molecules, including th