IB DP Chemistry: HL復(fù)習(xí)筆記18.1.4 Buffers
Buffers A?buffer solution?is a solution which resists changes in pH when small amounts of acid or base are added A buffer solution is used to keep the pH almost constant A buffer can consist of?wea...
IB DP Chemistry: HL復(fù)習(xí)筆記18.1.3 Indicators
Indicators An?acid-base?indicator?is a weak acid which dissociates to give an anion of a different colour Consider a weak acid, HIn: HIn (aq)? + H2O (l)? ? H3O+?(aq) + In–?(aq) colour 1? ? ? ? ? ? ...
IB DP Chemistry: HL復(fù)習(xí)筆記18.1.2 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 features of a pH curve ...
IB DP Chemistry: HL復(fù)習(xí)筆記18.1.1 Lewis Theory
Lewis Theory of Acids & Bases A more general definition of acids and bases was given by G.N. Lewis who defined them as: A Lewis?acid?is an?electron pair acceptor A Lewis?base?is an?electron pai...
IB DP Chemistry: HL復(fù)習(xí)筆記17.1.2 Gibbs Free Energy & the Equilibrium Constant
Gibbs Free Energy & the Equilibrium Constant Gibbs Free Energy & the Equilibrium Constant The equilibrium constant,?Kc, gives no information about the individual rates of reaction It is ind...
IB DP Chemistry: HL復(fù)習(xí)筆記17.1.1 Applying the Equilibrium Law
Explaining Le Chatelier’s Principle Le Chatelier's principle Le Chatelier's principle says that if a change is made to a system at?dynamic equilibrium, the position of the equilibrium moves to mini...
英國(guó)A-level大考成績(jī)或?qū)⒀悠诠迹@對(duì)中國(guó)的國(guó)際學(xué)校考生有何影響？
近日，英國(guó)《衛(wèi)報(bào)》報(bào)道，由于AQA考試局宣布72小時(shí)罷工，今年夏天的GCSE 和 A - level 考試分?jǐn)?shù)或?qū)⑼七t發(fā)布。這對(duì)中國(guó)的國(guó)際學(xué)校考生有何影響？ 考試局罷工，大考成績(jī)延遲發(fā)布？ 據(jù)《衛(wèi)報(bào)》報(bào)道，AQA考試委員會(huì)...
IB DP Chemistry: HL復(fù)習(xí)筆記16.2.3 Activation Energy from Rate Constants
Activation Energy from Rate Constants at Different Temperatures Arrhenius Plots Arrhenius plots for two reactions with different activation energies can be drawn on the same graph Arrhenius plots f...
IB DP Chemistry: HL復(fù)習(xí)筆記16.2.2 Graphing the Arrhenius Equation
Graphing the Arrhenius Equation Finding the Activation Energy Very often, the Arrhenius equation is used to calculate the activation energy of a reaction A question will either give sufficient info...
IB DP Chemistry: HL復(fù)習(xí)筆記16.2.1 The Arrhenius Equation
The Arrhenius Equation The rate equation shows how each of the reactants in a reaction effects the rate of the reaction and it includes the rate constant,?k However,?k?only remains constant if the ...
IB DP Chemistry: HL復(fù)習(xí)筆記16.1.5 Mechanism Problems
Mechanism Problems Chemical kinetics can only?suggest?a reaction mechanism, they cannot prove it However, they can be used to disprove a proposed mechanism Elementary steps are the steps involved i...
NSS官方發(fā)布2022年英國(guó)大學(xué)滿(mǎn)意度調(diào)查結(jié)果！
近日全英學(xué)生調(diào)查 (NSS) 發(fā)布了2022年英國(guó)大學(xué)滿(mǎn)意度調(diào)查結(jié)果，324329名學(xué)生參加了調(diào)查，英國(guó)每所大學(xué)都會(huì)參與NSS，還有一些學(xué)院和其他高等教育機(jī)構(gòu)也參與其中。 英國(guó)學(xué)生辦公室 (OfS) 表示，NSS收集學(xué)生對(duì)課程質(zhì)...
