CollegeBoard發布SAT機考樣題，正式回應黃牛考位問題
今天，CollegeBoard正式放出了SAT機考樣題，并采取直播方式對機考模式進行講解，同時，首次正面回應了黃牛考位問題。 在今年1月份，CB宣布SAT進入機考時代，國際考場在2023年春季率先使用機考，自此，SAT機考正式...
AQA A Level Chemistry復習筆記5.6.2 pK?
pK? The range of values of?Ka?is very large and for weak acids, the values themselves are very small numbers Table of?Ka?values For this reason it is easier to work with another term ...
AQA A Level Chemistry復習筆記5.5.3 The Ionic Product of Water
The Ionic Product of Water In all aqueous solutions, an equilibrium exists in water where a few water molecules dissociate into protons and hydroxide ions We can derive an equilibrium consta...
AQA A Level Chemistry復習筆記5.5.2 pH & [H?]
pH & [H?] The acidity of an aqueous solution depends on the number of?H+?(H3O+) ions in solution The?pH?is defined as: pH = -log[H+] where [H+] is the concentration of hydrogen ions in m...
AQA A Level Chemistry復習筆記5.4.6 Fuel Cells
Fuel Cells A fuel cell is an electrochemical cell in which a fuel?donates?electrons at one electrode and oxygen?gains?electrons at the other electrode These cells are becoming more common in...
AQA A Level Chemistry復習筆記5.4.5 Lithium Cells
Lithium Cells Lithium ion cells power the laptop or mobile device you are probably reading this on The Noble Prize for Chemistry in 2019 was awarded to John B. Goodenough, M. Stanley Whittin...
AQA A Level Chemistry復習筆記5.4.4 Commercial Cells
Commercial Cells Electrochemical cells can be used as a commercial source of electrical energy Cells can be?non-rechargeable?(irreversible),?rechargeable?or?fuel cells Type of cells used in ...
AQA A Level Chemistry復習筆記5.4.3 Predicting Reactions
Predicting Reactions Direction of electron flow The?direction of electron flow?can be determined by comparing the?E??values of two half-cells in an electrochemical cell Cl2?(g) + 2e-?? 2Cl-?...
AQA A Level Chemistry復習筆記5.4.2 Standard Electrode Potentials
Standard Electrode Potentials Standard electrode potential The position of equilibrium and therefore the electrode potential depends on factors such as: Temperature Pressure of gases Concent...
AQA A Level Chemistry復習筆記5.3.3 Changes in Temperature & Pressure
Changes in Temperature & Pressure We can apply Le Chatelier's Principle to gaseous equilibria in the same way it is applied to aqueous systems Here's a reminder of how the principle work...
AQA A Level Chemistry復習筆記5.3.2 Partial Pressure
Partial Pressure The partial pressure of a gas is the pressure it exerts in a mixture of gases if it occupied the container on its own Partial pressure is given the symbol?p, so for a gas X,...
AQA A Level Chemistry復習筆記5.2.8 Rate Determining Step
Rate Determining Step Rate-determining step & intermediates A chemical reaction can only go as fast as the slowest part of the reaction So, the?rate-determining step?is the slowest step ...
