A Level H2 Chemistry Tuition and notes Singapore

 

     Hi, A similar reaction appeared in 2022 H2 Chemistry exam papers. This is known as the Michael reaction.   The bottom reaction is an example of mixed Aldol condensation. This reaction was of interest to Cambridge examiner in 2022.         This reaction is known as the Cannizzaro reaction. If I am not wrong, some NUS undergraduates only learned this reaction in NUS Year 4. Now Cambridge examiners are setting many undergraduate organic chemistry reactions, possibly with induction of new and smarter Cambridge and SEAB examiners who are possibly top PhD students in the top 10 universities. So students need to be well prepared for Chemistry exams.

 This appeared in 2022 H2 Chemistry Paper 3. Fluorine is the most electronegative element and is assigned a Pauli's value of 4.0

       Hi,   Some novel molecules appeared in 2022 H2 Chemistry Paper 1 and  2 exam papers. Here is an aldol: Here is an enolate ion: Here are allotropes of carbon. Graphene appeared in 2022 H2 Chemistry Paper 2. This elderly experienced Cambridge examiner adores this copper(II) complex: Selenium compounds appeared in 2022 H2 Chemistry Paper 2. Here is an acid that is analogous to sulfuric acid, since sulfur and selenium are in Group 16.       This is a thiol.     A thioacetic acid appeared in 2022 H2 Chemistry Paper 1.      

Hi, these are some interesting peroxy organic acids and use of peroxide in catalysing free radical addition. These questions are related to 2022 H2 Chemistry papers set by Cambridge-Singapore examiners.    

 Hi, phenanthroline appeared in UK Cambridge A levels Chemistry exam papers in Nov 2022. So this maybe of interest to students who are interested in Transition metals and their ligands. Ligand structure: Is this compound optically active?

 Hi, please try drawing the dot and cross diagrams of - P2O5 - N2O5 - NOCl - NO - NO2 - C3O - C2O3 - C2O - N2O2 - N2O These molecules are related to H2 Chemistry Exam Papers Question. All the best!

 Hi, diazonium salts appeared in 2022 H2 Chemistry Exam papers. So here is a related reaction of the diazonium salt, which is an azo dye formation. Azo dyes are used in the textile industry.

 Hi, the Cambridge examiners were thinking about these related reactions which appeared in 2022 H2 Chemistry exam papers.       Here is a link to a powerpoint file of keto esters and their related reactions: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwj_weez0OH_AhVQxzgGHVXrD-cQFnoECA0QAQ&url=https%3A%2F%2Fwww.vanderbilt.edu%2FAnS%2FChemistry%2FRizzo%2FChem220b%2FCh21.ppt&usg=AOvVaw1p-eFo_Nf13I8fdqclwmgT&opi=89978449

   Hi, diazonium salt appeared in 2022 Cambridge-Singapore H2 Chemistry papers. So here are some related reactions of diazonium salts.     Cambridge examiners were examining carboxylic acid derivatives (keto esters) and carbonyl condensation reactions in Cambridge-Singapore H2 Chemistry exam papers in 2022. Here is a related Mannich reaction.    

 Hi. Aldol condensation reaction had been appearing in Cambridge papers and JC H2 Chemistry prelim papers in the recent years. All thanks to the professor who created this diagram on internet, students who are hungry for success may learn this mechanism. Carbonyl chemistry is one of the most complex chapters in undergraduate chemistry course and now such questions appear in A level Chemistry papers.    

A similar reaction appeared in 2022 Cambridge papers.

 Chemistry of aqueous solutions - Acid-base equilibrium structured questions (35 pages) https://drive.google.com/file/d/10GW4y0YmPUYu-4K_czSFVl29b00pPiFY/view?usp=share_link

 Carbonyl compounds Structured questions with answers - more than 100 pages long. https://drive.google.com/file/d/1ww3Q_Cxc1EKVYJm1gGrK8i1siTayCzN9/view?usp=share_link

This reaction mechanism may be of interest to students because similar reactions have appeared in Cambridge exam papers last 2 years.                                   Et stands for an ethyl group.

  Grateful to the owner for creating this on internet.

      I found this slide from the internet. Grateful  for the owner who created this slide. 

   In organic chemistry , the Diels–Alder reaction is a chemical reaction between a conjugated diene and a substituted alkene to form a substituted cyclohexene derivative. Draw the formula of the product C when the following diene and cycloalkene undergo Diels Alder reaction. Also, outline the mechanism of this pericyclic Diels-Alder reaction.

  Cyclopropane rings are precursors in synthesizing certain pharmaceutical medicine and substituted cyclopropane is also involved in biochemical pathways (biosynthesis of certain biomolecules) of   bacteria. The following reaction shows part of the synthesis for   a cyclopropane compound.         The above reaction involves a negatively-charge organic intermediate which is relatively stabilised, which eventually forms the cyclopropane compound.   (a)     Suggest the reaction types for steps 1 and 2 and draw the structural formula of the organic intermediate. (b)     How is the intermediate stabilised?   a    Propose a mechanism for the above reaction. (c)      Which has more conformational stability, cyclopropane or cyclohexane? Explain briefly your answer.

 In organic chemistry , the Diels–Alder reaction is a chemical reaction between a conjugated diene and a substituted alkene to form a substituted cyclohexene derivative. Draw the formula of the product Z when the following diene and cycloalkene undergo Diels Alder reaction.