JC Chemistry Tuition
Reminder: Third Term is here. If you haven’t been putting in 100% into your studies, now’s the time to start! Remember to pace yourself though, studying late into the night makes for unproductive school day the next day. Weather’s also erratic and there’s some flu clusters around in schools. Please have at least 2L of […]
The Random Recently, i received a colorful brochure in my mailbox of a particular pre-school/kindergarden in Central Tampines. It is glossy with a lot of infographics and photos, about 5-6 pages long, A4 size. Being a business owner now, i thought to myself this publicity would have cost thousands of dollars. I read through the […]
Enthalpy Change of Reaction Some of you may be thinking the enthalpy change of reaction just a general definition for any reaction but the units actually don’t refer to any specific reactants or products. It refers to the molar quantities of all the reactants and products. For eg, 2H2 (g) + 2O2 (g) → 2H2O (l) It […]
Strength of Hydrogen Bond Qn: Which of these compounds has the strongest hydrogen bond, HF, H2O or NH3? How do we estimate the strength of hydrogen bond? Ans: HF. Due to the largest electronegativity difference between H and F. Followed by H2O and then NH3. Qn: But then why does water have the highest boiling […]
Common mistakes in drawing hydrogen bond One of the most common mistakes is to write the dipole across the hydrogen bond, e.g. A dipole exists as a pair, partial positive and partial negative. It also depicts the uneven electron density distribution in a covalent bond thus it first forms in a single molecule where the hydrogen […]
Thankful that i had the chance to teach such a wonderful bunch of students before i left the college. Even though i told them i didn’t need one as i wouldn’t have any occasion to wear it. Thank you 17S305, for my last class t-shirt 🙂 Home
Organic deductive questions If the organic deductive questions gives the molecular formula, see if the number of C and H is comparable. In addition, if the molecule contains more than 6 carbon atoms, the compound is likely to contain a benzene ring. Even if C and H is not comparable, the degree of unsaturation can tell us […]
Halides test Ans: The purpose of acidifying is to neutralise the excess OH- ions that will form a precipitate with Ag+ ions. This is an often overlooked step in the halides test. Another common question is why does the precipitate take varying time to appear? This has to do with the type of halide we […]
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