Organic Chemistry Rules: Never violate these!!
Disclaimer: This posting applies to Undergraduate organic chemistry. This does NOT apply to crazy physicists who create all sorts of insanity in a laboratory that cannot exist outside a xenon forcefield.
In organic chemistry, like in life itself, there are rules. Some of them (known as the “always/never” rules) should never be violated, such as always wash your hands leaving the bathroom, or never spit in church. Other rules (known as the “sometimes” rules) are guides that you should be aware of rather than hard rules.
Thus, we present a blog post called “Organic Chemistry Rules: ALWAYS, Sometimes, NEVER.”
ALWAYS/NEVER:
1) Hydrogen ALWAYS has only one bond to it. You will never see an organic molecule that has two bonds to hydrogen.
2) Carbon NEVER has more than four bonds. EVER!
3) Alkaline metals (Li, Na, ect) and alkali earth metals (Be, Mg, Ca, ect) can NEVER be negatively charged. They will always be neutral or positively-charged ions in solution.
4) Noble gases are NEVER a part of any organic molecule. Because they have a full octet, they have very little reason to create a covalent bond.
5) Electrons ALWAYS flow from negative to positive. This is a biggie. And because of this, rule #6 exists.
6) Reaction arrows ALWAYS point from negative to positive. Always point from the nucleophile to the electrophile.
Sometimes:
– Carbon can have 4 bonds (neutral), 3 bonds (positive, negative), or even 2 bonds (carbene)
– Halogens USUALLY have one bond, but can occasionally have two.
– Nitrogen usually has 3 bonds (neutral), 4 bonds (positive) or 2 bonds (negative)
– Oxygen usually has 2 bonds, but can have only 1 bond (negative) or 3 bonds (positive)
– Phosphorous is USUALLY an oxophile, meaning if it can react with oxygen, it will.
This brings us to another point about knowing the common states of organic atoms. This can really help you in solving organic chemistry if you know the normal state of organic atoms [this is a link to one of our favorite blog posts]