A-level重考影響申請英國G5嗎？
今年的A-level大考結(jié)束了，包括國際考試局和英國本土。然而今年的形勢，小編也給大家說了，英國打算削減A-level高分6萬個，今年上萬人將無緣大學(xué)錄取！考試發(fā)揮失利，或成績不錯但報空了的同學(xué)，怎么辦？這就引出...
AQA A Level Chemistry復(fù)習(xí)筆記5.6.5 Buffers
Acid & Basic Buffers A?buffer solution?is a solution which resists changes in pH when small amounts of acids or alkalis are added A buffer solution is used to keep the pH almost constant...
AQA A Level Chemistry復(fù)習(xí)筆記5.6.4 pH Curves
pH Curves During a titration a pH meter can be used and a pH curve plotted A pH curve is a graph showing how the pH of a solution changes as the acid (or base) is added The result is charact...
AQA A Level Chemistry復(fù)習(xí)筆記5.6.3 Titrations
Titrations Volumetric analysis?is a process that uses the volume and concentration of one chemical reactant (a standard solution) to determine the concentration of another unknown solution T...
AQA A Level Chemistry復(fù)習(xí)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(fù)習(xí)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(fù)習(xí)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(fù)習(xí)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(fù)習(xí)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...
