I am back from Faerie Mountain :D and no I did not see Puck. Neither did I see any flying foxes up there on the snow mountain o.o
Here's the Random Trivia for today:
Shadow Fiend's Shadowraze has a 0.75 second cast time. It can be cancelled with the S command at any time during this cast time. Cancelling it within 0.5 seconds cancels the raze, but after 0.5 seconds, the raze is considered cast and S-cancelling it will shorten the raze cast time from 0.75 seconds to 0.5 seconds.
This is how PIS/Yamateh/Loda/KuroKy/everyone else razes so fast :o
:3
Friday, December 23, 2011
Wednesday, December 21, 2011
Random DotA Trivia #2
I'm in China now yay. Still have blogger ha.
The Random Trivia for today is:
All ultimate spells bypass magic immunity, but magic immunity grants immunity to magic damage. Therefore all ultimate spells will deal no damage but still have their effects.
Implications of this are:
1. Ultimates which purely deal damage e.g. Slayer's Laguna Blade have no effect on magic immune targets except wasting it.
2. Ultimates which disable will still disable e.g. Doom Bringer's Doom, Bane Elemental's Fiend's Grip etc, except they deal no damage.
3. Ultimates based on non-ultimate spells will have no effect on magic immune targets. e.g. Tidehunter's Ravage, Sand King's Epicenter
:3
The Random Trivia for today is:
All ultimate spells bypass magic immunity, but magic immunity grants immunity to magic damage. Therefore all ultimate spells will deal no damage but still have their effects.
Implications of this are:
1. Ultimates which purely deal damage e.g. Slayer's Laguna Blade have no effect on magic immune targets except wasting it.
2. Ultimates which disable will still disable e.g. Doom Bringer's Doom, Bane Elemental's Fiend's Grip etc, except they deal no damage.
3. Ultimates based on non-ultimate spells will have no effect on magic immune targets. e.g. Tidehunter's Ravage, Sand King's Epicenter
:3
Tuesday, December 20, 2011
Random DotA Trivia #1
Whee its holiday times!
Oh wait that was last month. Holidays almost over already blah.
Anyway I'm going on vacation again so I shall revive this blog for the most useless thing ever: Random DotA Trivia (Y)
Today's trivia is:
"Axe's Counter Helix is triggered by the attack front-swing, not the attack itself nor the command. "
Implications of this are:
1. Repeatedly pressing A and left clicking on Axe will not trigger Counter Helix.
2. Pressing S repeatedly while affected by Berserker's Call INCREASES the rate at which Axe spins. This is because Berserker's Call issues an attack command on Axe everytime you issue another command, and everytime the attack command is issued at such close range the front-swing plays, giving a 17% chance to spin.
3. Some spells use the attack front-swing as the casting animation. Examples are Lion's Impale and Tidehunter's Gush. Casting these spells on Axe WILL trigger Counter Helix because it plays the attack front-swing.
4. Counter Helix triggers the moment the attack front-swing plays, not when the projectile hits Axe (for ranged attackers).
:3
Oh wait that was last month. Holidays almost over already blah.
Anyway I'm going on vacation again so I shall revive this blog for the most useless thing ever: Random DotA Trivia (Y)
Today's trivia is:
"Axe's Counter Helix is triggered by the attack front-swing, not the attack itself nor the command. "
Implications of this are:
1. Repeatedly pressing A and left clicking on Axe will not trigger Counter Helix.
2. Pressing S repeatedly while affected by Berserker's Call INCREASES the rate at which Axe spins. This is because Berserker's Call issues an attack command on Axe everytime you issue another command, and everytime the attack command is issued at such close range the front-swing plays, giving a 17% chance to spin.
3. Some spells use the attack front-swing as the casting animation. Examples are Lion's Impale and Tidehunter's Gush. Casting these spells on Axe WILL trigger Counter Helix because it plays the attack front-swing.
4. Counter Helix triggers the moment the attack front-swing plays, not when the projectile hits Axe (for ranged attackers).
:3
Monday, September 26, 2011
Chemical of the Day: Cyclohexane
Err today's chemical is cyclohexane! Thankfully its not too interesting, since I want to sleep : <
Stupid promos are going to kill me soon.
Name: Cyclohexane
IUPAC Name: Cyclohexane
Other names: None (not surprising right there.)
Molecular Formula: C6H12 (note resemblence to hexene)
Molar Mass: 84.16g/mol
Appearance (at r.t.p.): Colourless liquid
Solubility in water: Immiscible (not surprising either)
Dipole Moment: 0.0D (SURPRISE!)
Synthesis:
1. Benzene can be forcibly hydrogenated through the use of the strong catalyst, for example Pd/C under extreme temperatures and pressures (over 250atm pressure required, not sure the temperature). However a more powerful catalyst such as rhodium activated by acid is often used in industrial processes (this requires only 70Degrees C temperature and 20atm pressure of H2 gas).
I don't really know of any other synthesis pathways, except by funny things like intra-molecular nucleophilic substitution or something.
This might work in a lab, but the yield is probably not appreciable.
Properties:
1. Cyclohexane is most commonly studied for being the smallest alicyclic hydrocarbon with absolutely no ring strain at all. This is due to the stability of the "chair" conformer. Conformations in cyclohexane draws plenty of interest, and for a good reason too. It was once thought that alicyclic hydrocarbons were all planar (as if they were aromatic XD) but in reality its not the case. Each carbon in the ring is sp3 hybridized, hence is tetrahedral in shape. The 12 hydrogens are divided into 2 groups: 6 "axial" hydrogens, and 6 "equitorial" positions. The positions of the groups attached to the cyclohexane ring makes a difference to its reaction chemistry (especially regioselective processes). Lastly, cyclohexane also exhibits a "ring flip" rearrangement, where the axial and equitorial positions interchange with each other.
2. Cyclohexane exists only in 2 stable conformers, the "chair" conformer and the "boat" conformer. Suppose one of these carbons is substituted by a halogen atom. One look shows that typical nucleophilic substitution reactions (SN2 in this case) will not work on it as it is not possible for the nucleophile to attack from the opposite side of the carbon; it is blocked by the ring. Therefore, bromocyclohexane does NOT form cyclohexanol even in aqueous NaOH; instead it undergoes the more preferred elimination reaction to form cyclohexene.
3. It is non-polar and hydrophobic. Not surprising at all, considering its a hydrocarbon. Its main forces of attraction are dispersion forces, while water associates with hydrogen bonding. Needless to say solvent - solvent interactions and solute - solute interactions are much stronger than solvent-solute interactions; there's no way cyclohexane will dissolve in water.
4. Cyclohexane is highly flammable. Not a surprise once again, being a hydrocarbon.
Reactions:
Well cyclohexane is a non-polar, hydrophobic, alicyclic hydrocarbon, so it is not very reactive. It is forcibly protonated by a superacid such as the HF + SbF5 system, leading to hydrocarbon cracking.
Substituted cyclohexanes undergo their usual reactions with little difference; halides still undergo Grignard reactions, organometallic coupling still works as per normal. Alcohols can still be substituted to give a halide, and dehydrated to obtain an alkene. Esterification also occurs as per normal.
Other random crap:
Cyclohexane is boring. At least that means I can sleep. Yay!
Stupid promos are going to kill me soon.
Name: Cyclohexane
IUPAC Name: Cyclohexane
Other names: None (not surprising right there.)
Molecular Formula: C6H12 (note resemblence to hexene)
Molar Mass: 84.16g/mol
Appearance (at r.t.p.): Colourless liquid
Solubility in water: Immiscible (not surprising either)
Dipole Moment: 0.0D (SURPRISE!)
Synthesis:
1. Benzene can be forcibly hydrogenated through the use of the strong catalyst, for example Pd/C under extreme temperatures and pressures (over 250atm pressure required, not sure the temperature). However a more powerful catalyst such as rhodium activated by acid is often used in industrial processes (this requires only 70Degrees C temperature and 20atm pressure of H2 gas).
I don't really know of any other synthesis pathways, except by funny things like intra-molecular nucleophilic substitution or something.
This might work in a lab, but the yield is probably not appreciable.
Properties:
1. Cyclohexane is most commonly studied for being the smallest alicyclic hydrocarbon with absolutely no ring strain at all. This is due to the stability of the "chair" conformer. Conformations in cyclohexane draws plenty of interest, and for a good reason too. It was once thought that alicyclic hydrocarbons were all planar (as if they were aromatic XD) but in reality its not the case. Each carbon in the ring is sp3 hybridized, hence is tetrahedral in shape. The 12 hydrogens are divided into 2 groups: 6 "axial" hydrogens, and 6 "equitorial" positions. The positions of the groups attached to the cyclohexane ring makes a difference to its reaction chemistry (especially regioselective processes). Lastly, cyclohexane also exhibits a "ring flip" rearrangement, where the axial and equitorial positions interchange with each other.
2. Cyclohexane exists only in 2 stable conformers, the "chair" conformer and the "boat" conformer. Suppose one of these carbons is substituted by a halogen atom. One look shows that typical nucleophilic substitution reactions (SN2 in this case) will not work on it as it is not possible for the nucleophile to attack from the opposite side of the carbon; it is blocked by the ring. Therefore, bromocyclohexane does NOT form cyclohexanol even in aqueous NaOH; instead it undergoes the more preferred elimination reaction to form cyclohexene.
3. It is non-polar and hydrophobic. Not surprising at all, considering its a hydrocarbon. Its main forces of attraction are dispersion forces, while water associates with hydrogen bonding. Needless to say solvent - solvent interactions and solute - solute interactions are much stronger than solvent-solute interactions; there's no way cyclohexane will dissolve in water.
4. Cyclohexane is highly flammable. Not a surprise once again, being a hydrocarbon.
Reactions:
Well cyclohexane is a non-polar, hydrophobic, alicyclic hydrocarbon, so it is not very reactive. It is forcibly protonated by a superacid such as the HF + SbF5 system, leading to hydrocarbon cracking.
Substituted cyclohexanes undergo their usual reactions with little difference; halides still undergo Grignard reactions, organometallic coupling still works as per normal. Alcohols can still be substituted to give a halide, and dehydrated to obtain an alkene. Esterification also occurs as per normal.
Other random crap:
Cyclohexane is boring. At least that means I can sleep. Yay!
Saturday, September 24, 2011
Chemical of the Day: Phenol
Lol today's Chemical of the Day is phenol. At first I wanted to do benzene but I realized that wasn't as interesting :D Anyway lets get started.
Name: Phenol (wow!)
IUPAC name: Phenol (lol)
Other names: Carbolic acid, hydroxybenzene, benzenol, phenylic acid, phenic acid
*comment: strictly speaking, phenol is not an acid, but we'll talk about this later
Molecular formula: C6H5OH
Molar mass: 94.11g/mol
Appearance (at r.t.p.): transparent crystalline solid
Solubility in water: 8.3g/100mL (decent)
Dipole moment: 1.7D (rather large, but not unexpected)
Synthesis:
1. The most common synthesis pathway for phenol is the Cumene Process.
Benzene + Propene + [O] --> Acetone + Phenol
The intermediate in this reaction is cumene (isopropylbenzene) which is formed by the Friedel-Crafts alkylation of propene onto benzene. The reaction continues via a radical mechanism followed by a rearrangement (Hock's Rearrangement) and elimination reaction to produce acetone and phenol.
2. Another common industrial synthesis pathway for phenol is Dow's Process
Chlorobenzene + NaOH (aq) --340 degrees C, 170atm--> Phenol + NaCl
This reaction is interesting because it proceeds via a benzyne intermediate (HCl is eliminated from chlorobenzene, if you'd like) and OH- adds to the triple bond in to form phenol.
There are few synthesis routes available in the laboratory, since the benzene ring is inert to electrophilic addition and oxidation. As a result most of the phenol used in the lab is obtained via the petrochemical industry (lol).
Properties:
1. The hydroxyl group attached to the benzene ring is a strongly activating group due to oxygen being able to delocalize its lone pairs into the pi electron system. This makes the benzene ring extremely favourable to electrophilic substitution reactions. In fact, nitrating a benzene ring with a hydroxyl group attached no longer requires concentrated nitric acid; dilute nitric acid is sufficient. Furthermore, halogenation of phenol no longer requires the catalyst (it occurs spontaneously) and halogenates at all 3 o- and p- positions since the halide group is such a weak deactivator but hydroxyl is a strong enough activator to cause polysubstitution. Friedel-Crafts alkylation and acylation still require their Lewis acid catalysts, but occur in much milder conditions (e.g. phenol reacts with alcohols in the presence of an acid catalyst to add the alkyl group) and polyalkylation frequently.
2. Phenol is actually the enol tautomer of its keto-enol pair. The keto form is cyclohexa-2,4-dienone and is extremely unstable. The formation of a C=O bond rather than a C=C bond is favourable, but that is more than offset by the loss of resonance stability due to aromaticity. Phenol is hence a notable exception to the norm of keto-enol tautomerism, since most such pairs usually favour the keto form.
3. Phenol is not an acid, but the word "acid" commonly pops up in its name. Its pKa in water is 9.95, about 1 million times more acidic than most aliphatic alcohols such as ethanol (pKa 15.9). This is due to the stability of the phenoxide / phenolate anion which is resonance stabilized by the benzene ring. An alternate explanation is that there is orbital overlap between the lone pairs of the oxygen atom and the delocalized pi network.
4. Phenol is corrosive, but there is no evidence whether it is carcinogenic (benzene, however is a known carcinogen).
Reactions:
1. The obvious, electrophilic substitution. Phenol is a special case though, since it undergoes Friedel-Crafts acylation in 2 different ways. Phenol has 2 sites to which electrophiles may attack: the electrically rich benzene ring, and the lone pairs of the oxygen atom.
When the electrophilic attack occurs on the benzene ring, its termed C-acylation and the "normal" Friedel-Crafts acylation occurs. When the electrophilic attack occurs on the oxygen however, O-acylation occurs and an aryl ester is formed.
2. Phenol + zinc powder --> Benzene
One of the more useful reactions to know, when they ask for funny things like converting phenol into methyl phenyl ketone.
3. Use of the phenoxide anion:
Williamson ether synthesis with the phenoxide anion allows for easy synthesis of aryl ethers.
The phenoxide anion is a potent (though not very strong) base and a strong nucleophile. It can attack ketones and aldehydes.
Other random crap:
None I think. Most of the interesting stuff is up there already :D
Let's see what should Fan Yi do next.
Name: Phenol (wow!)
IUPAC name: Phenol (lol)
Other names: Carbolic acid, hydroxybenzene, benzenol, phenylic acid, phenic acid
*comment: strictly speaking, phenol is not an acid, but we'll talk about this later
Molecular formula: C6H5OH
Molar mass: 94.11g/mol
Appearance (at r.t.p.): transparent crystalline solid
Solubility in water: 8.3g/100mL (decent)
Dipole moment: 1.7D (rather large, but not unexpected)
Synthesis:
1. The most common synthesis pathway for phenol is the Cumene Process.
Benzene + Propene + [O] --> Acetone + Phenol
The intermediate in this reaction is cumene (isopropylbenzene) which is formed by the Friedel-Crafts alkylation of propene onto benzene. The reaction continues via a radical mechanism followed by a rearrangement (Hock's Rearrangement) and elimination reaction to produce acetone and phenol.
2. Another common industrial synthesis pathway for phenol is Dow's Process
Chlorobenzene + NaOH (aq) --340 degrees C, 170atm--> Phenol + NaCl
This reaction is interesting because it proceeds via a benzyne intermediate (HCl is eliminated from chlorobenzene, if you'd like) and OH- adds to the triple bond in to form phenol.
There are few synthesis routes available in the laboratory, since the benzene ring is inert to electrophilic addition and oxidation. As a result most of the phenol used in the lab is obtained via the petrochemical industry (lol).
Properties:
1. The hydroxyl group attached to the benzene ring is a strongly activating group due to oxygen being able to delocalize its lone pairs into the pi electron system. This makes the benzene ring extremely favourable to electrophilic substitution reactions. In fact, nitrating a benzene ring with a hydroxyl group attached no longer requires concentrated nitric acid; dilute nitric acid is sufficient. Furthermore, halogenation of phenol no longer requires the catalyst (it occurs spontaneously) and halogenates at all 3 o- and p- positions since the halide group is such a weak deactivator but hydroxyl is a strong enough activator to cause polysubstitution. Friedel-Crafts alkylation and acylation still require their Lewis acid catalysts, but occur in much milder conditions (e.g. phenol reacts with alcohols in the presence of an acid catalyst to add the alkyl group) and polyalkylation frequently.
2. Phenol is actually the enol tautomer of its keto-enol pair. The keto form is cyclohexa-2,4-dienone and is extremely unstable. The formation of a C=O bond rather than a C=C bond is favourable, but that is more than offset by the loss of resonance stability due to aromaticity. Phenol is hence a notable exception to the norm of keto-enol tautomerism, since most such pairs usually favour the keto form.
3. Phenol is not an acid, but the word "acid" commonly pops up in its name. Its pKa in water is 9.95, about 1 million times more acidic than most aliphatic alcohols such as ethanol (pKa 15.9). This is due to the stability of the phenoxide / phenolate anion which is resonance stabilized by the benzene ring. An alternate explanation is that there is orbital overlap between the lone pairs of the oxygen atom and the delocalized pi network.
4. Phenol is corrosive, but there is no evidence whether it is carcinogenic (benzene, however is a known carcinogen).
Reactions:
1. The obvious, electrophilic substitution. Phenol is a special case though, since it undergoes Friedel-Crafts acylation in 2 different ways. Phenol has 2 sites to which electrophiles may attack: the electrically rich benzene ring, and the lone pairs of the oxygen atom.
When the electrophilic attack occurs on the benzene ring, its termed C-acylation and the "normal" Friedel-Crafts acylation occurs. When the electrophilic attack occurs on the oxygen however, O-acylation occurs and an aryl ester is formed.
2. Phenol + zinc powder --> Benzene
One of the more useful reactions to know, when they ask for funny things like converting phenol into methyl phenyl ketone.
3. Use of the phenoxide anion:
Williamson ether synthesis with the phenoxide anion allows for easy synthesis of aryl ethers.
The phenoxide anion is a potent (though not very strong) base and a strong nucleophile. It can attack ketones and aldehydes.
Other random crap:
None I think. Most of the interesting stuff is up there already :D
Let's see what should Fan Yi do next.
Friday, September 23, 2011
Chemical of the Day Preamble
Woot I'm finally back after ignoring for so long -.- blogging is not so fun or easy as I thought... sometimes.
Anyway, Fan Yi and I started this Chemical of the Day thingy, where we got 1 (hopefully interesting) chemical everyday featured. We're alternating, and he's taking inorg stuff (surprise!) and I take the org stuff. Hoping for some cool things :D
Anyway, I need to study for promos! I'm going to die at this rate after screwing up econs rawr.
Anyway, Fan Yi and I started this Chemical of the Day thingy, where we got 1 (hopefully interesting) chemical everyday featured. We're alternating, and he's taking inorg stuff (surprise!) and I take the org stuff. Hoping for some cool things :D
Anyway, I need to study for promos! I'm going to die at this rate after screwing up econs rawr.
Friday, July 8, 2011
Week-end To-do's )=
Anyway I've been slacking off the week after blocks, so taking the time off this weekend to do some work >.<
Here's what I have to do (blah).
1. Math Tutorial 5C
2. Chem Tutorial 6
3. Read Physics Oscilliations notes
4. Write my new 2C system
5. Do EoM <-- >.<
6. Do physics AA
Lol I have a feeling this is short of what I actually have to do, but we'll see if I can finish :P
Here's what I have to do (blah).
1. Math Tutorial 5C
2. Chem Tutorial 6
3. Read Physics Oscilliations notes
4. Write my new 2C system
5. Do EoM <-- >.<
6. Do physics AA
Lol I have a feeling this is short of what I actually have to do, but we'll see if I can finish :P
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