CIE A Level Chemistry复习笔记1.5.5 Hess’s Law
Hess Cycles Hess’s Law states that:"The total enthalpy change in a chemical reaction is independent of the route by which the chemical reaction takes place as long as the initial and final conditio...
Hess Cycles Hess’s Law states that:"The total enthalpy change in a chemical reaction is independent of the route by which the chemical reaction takes place as long as the initial and final conditio...
Enthalpy & Bond Energies During a reaction, enthalpy changes take place because bonds are being broken and formed Energy (in the form of heat) is needed to overcome attractive forces between at...
Enthalpy Changes at Standard Conditions To fairly compare the changes in enthalpy between reactions, all reactions should be carried out under standard conditions These standard conditions are: A p...
Energy Level Diagrams An energy level diagram is a diagram that shows the energies of the reactants, the transition state(s) and the products of the reaction with time The transition state is a sta...
Enthalpy Changes The total chemical energy inside a substance is called the enthalpy (or heat content) When chemical reactions take place, changes in chemical energy take place and therefore the en...
Effects of Bonding & Structure on Physical Properties Different types of structure and bonding have different effects on the physical properties of substances such as their melting and boiling ...
Lattice Structures Most ionic, metallic and covalent compounds are crystalline lattice The ions, atoms or molecules are arranged in a regular and repeating arrangement Giant ionic lattices An ionic...
Gases: Ideal Gas Law & Equation Kinetic theory of gases The kinetic theory of gases states that molecules in gases are constantly moving The theory makes the following assumptions: The gas mole...
Gases: Gas Pressure Gases in a container exert a pressure as the gas molecule are constantly colliding with the wall of the container Gas particles exert a pressure by constantly colliding with the...
Dot & Cross Diagrams Dot and cross diagrams are diagrams that show the arrangement of the outer-shell electrons in an ionic or covalent compound or element The electrons are shown as dots and c...
A-Level大考今日放榜,同学们可以抓紧时间查询自己的分数。出分后,AS阶段的考生若对此次A-Level成绩满意,即可着手准备2023年的留学事宜;A2阶段的考生若成绩满足院校申请要求,那么后续只需等待相应院校的确认...
此前由于疫情原因,各个国际大考相继出现考试形式的更改问题,其中个别地区的A-Level大考就因此转换为POE或TAG形式,许多同学不免担忧评估出分会导致高分通胀情况。 同学们的担忧是否会成为既定事实?相信随着今...
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