Edexcel A Level Chemistry:复习笔记1.8.4 Hess Cycles
Constructing Hess Cycles In 1840, the Russian chemist Germain Hess formulated a law which went on to be known as Hess’s Law This went on to form the basis of one of the laws of thermodynamics. The ...
Edexcel A Level Chemistry:复习笔记1.8.3 Calorimetry
Calculating Energy Transferred, Q Measuring enthalpy changes Calorimetry is the measurement enthalpy changes in chemical reactions A simple calorimeter can be made from a polystyrene drinkin...
Edexcel A Level Chemistry:复习笔记1.8.2 Enthalpy Level Diagrams
Enthalpy Level Diagrams 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 th...
Edexcel A Level Chemistry:复习笔记1.8.1 Enthalpy Changes
Enthalpy Change Definitions To be able to compare the changes in enthalpy between reactions, all thermodynamic measurements are carried out under standard conditions These standard condition...
Edexcel A Level Chemistry:复习笔记1.7.4 Yield & Atom Economy
Yield & Atom Economy Percentage yield In a lot of reactions, not all reactants react to form products which can be due to several factors: Other reactions take place simultaneously The r...
Edexcel A Level Chemistry:复习笔记1.7.3 Error & Uncertainty
Error & Uncertainty An error is the difference between a value or quantity obtained in an experiment and an accepted or literature value for an experiment There are two types of errors i...
Edexcel A Level Chemistry:复习笔记1.7.2 Titrations
Titration Calculations Volumetric Analysis Volumetric analysis is a process that uses the volume and concentration of one chemical reactant (standard solution) to determine the concentration...
2022年IG化学部分真题解析！
截至目前，2022年夏季大考的成绩都出来了。根据Ofqual官方数据，今年参加IGCSE/GCSE考试的同学又有所增加，共有5349250人报名参加GCSE夏季大考。 2022年IGCSE整体成绩趋势 今年整体成绩要比去年低。回想过去两年...
Edexcel A Level Chemistry:复习笔记1.7.1 Reacting Volume Calculations
Reacting Volume Calculations Reacting volume calculations are commonly associated with the reactions of gases All gases occupy the same volume under the same conditions At room temperature a...
