ASRJC 2024 H2 Chem Atoms, Molecules, and Stiochiometry Notes

2024 JC1 H2 The Mole Concept, Stoichiometry & Redox Reactions 2024/ASRJC/Chemistry 1 Anderson Serangoon Junior College JC1 H2 Chemistry THE MOLE CONCEPT, STOICHIOMETRY & REDOX REACTIONS Learning Outcomes [the term relative formula mass or Mr will be used for ionic compounds] Candidates should be able to: (a) define the terms relative atomic, isotopic, molecular and formula mass (b) define the term mole in terms of the Avogadro constant (c) calculate the relative atomic mass of an element given the relative abundances of its isotopes (d) define the terms empirical and molecular formula (e) calculate empirical and molecular formulae using combustion data or composition by mass (f) write and/or construct balanced equations (g) perform calculations, including use of the mole concept, involving: (i) reacting masses (from formulae and equations) (ii) volumes of gases (e.g. in the burning of hydrocarbons) (iii) volumes and concentrations of solutions [when performing calculations, candidates’ answers should reflect the number of significant figures giv en or asked for in the question] (h) deduce stoichiometric relationships from calculations such as those in (g) (i) describe and explain redox processes in terms of electron transfer and/or of changes in oxid ation number (oxidation state) (j) construct redox equations using the relevant half−equations (k) Describe and explain the use of Fe 3+/Fe2+, MnO4−/Mn2+, Cr2O72−/Cr3+ and iodometric titration as examples of redox systems References 1. Chemistry for Advanced Level, Peter Cann & Peter Hughes 2. Chemistry, JGR Briggs 3. Chemistry in Context, 5th edition, Graham Hill & John Holman 4. A−Level Chemistry, Fourth Edition, E.N. Ramsden 5. Chemistry, Sixth Edition, Steven S. Zumdahl & Susan A. Zumdahl 6. Chemistry: The Molecular Nature of Matter and Change, 4th Edition, Martin S. Silberberg

2024 JC1 H2 The Mole Concept, Stoichiometry & Redox Reactions 2024/ASRJC/Chemistry 2 TABLE OF CONTENTS Pg 1. Relative Masses of Atoms and Molecules ……...……………………………………. 3 1.1 Relative Masses of Atoms …………………………………………………………. 3 1.2 Relative Molecular Mass and Relative Formula Mass …………………………... 4 2. The Mole, The Avogadro Constant and Molar Mass ……………………………..… 6 2.1 The Mole, The Avogadro Constant ………………………………………………. 6 2.2 Molar Mass ………………………………………………………………………….. 7 3. Stoichiometry ………………………………………………………………………….….. 8 3.1 Balancing Chemical Equations …………………………………………………… 8 3.2 Stoichiometry involving Gases ……………………………………………………. 9 3.2.1 Relationship between the Mole and Volume of Gases ……………….. 9 3.2.2 Molar Volumes of Gases ………………………………………………… 9 3.3 Calculations involving Reacting Mas