Octet

Octet / Study Tips

SN1 vs SN2

SN1 vs SN2 - organic chemistry study tip. Mnemonic: SN2: Strong Nucleophile, Secondary or primary. SN2 works best with methyl and 1° substrates (steric hindrance matters). SN1 works best with 3° (carbocation stability matters). 2° can go either way - look at...

mechanism

Study Tip details

Topic

SN1 vs SN2

Mnemonic

SN2: Strong Nucleophile, Secondary or primary

Tip

SN2 works best with methyl and 1° substrates (steric hindrance matters). SN1 works best with 3° (carbocation stability matters). 2° can go either way - look at nucleophile strength and solvent.

Category

mechanism

This is one row of the Mnemonics sheet - print all 25 mnemonics and study tips on one page.

Study Tips

Related Content

Source collection

E1 vs E2

E1 vs E2 - organic chemistry study tip. Mnemonic: E2: Everything (H and LG) leaves at the same time. E2 requires anti-periplanar geometry (H and leaving group 180° apart). E1 makes the more stable carbocation first. Bulky bases favor elimination over substitu...

mechanism

Zaitsev vs Hofmann Products

Zaitsev vs Hofmann Products - organic chemistry study tip. Mnemonic: Zaitsev = "Z" for "Ze more substituted" alkene. Zaitsev (most substituted alkene) is favored with small bases. Hofmann (less substituted) is favored with bulky bases like KOtBu or with poor...

mechanism

Markovnikov's Rule

Markovnikov's Rule - organic chemistry study tip. Mnemonic: Rich get richer: H goes to C with more H's. In electrophilic addition, the electrophile (usually H⁺) adds to the carbon with MORE hydrogens, forming the more stable carbocation on the more substitute...

mechanism

Anti-Markovnikov Addition

Anti-Markovnikov Addition - organic chemistry study tip. Mnemonic: Peroxides promote anti pattern. HBr + peroxides (ROOR) = anti-Markovnikov via radical mechanism. Only works with HBr (not HCl or HI). Hydroboration-oxidation also gives anti-Markovnikov alcoho...

mechanism

Carbocation Stability

Carbocation Stability - organic chemistry study tip. Mnemonic: 3° > 2° > 1° > methyl (like a countdown). More substituted carbocations are more stable due to hyperconjugation and inductive effects. Watch for rearrangements (hydride and methyl shifts) to form...

mechanism

Nucleophilicity vs Basicity

Nucleophilicity vs Basicity - organic chemistry study tip. Nucleophilicity = how fast it attacks carbon (kinetic, steric matters). Basicity = equilibrium with proton (thermodynamic, pKa matters). Good nucleophiles aren't always strong bases (e.g., I⁻, RS⁻).

mechanism

Study guides

Related study guides

Free, in-depth guides that put this material in context.

Study reactions without memorizingAce organic chemistry examsArrow-pushing basicsAll guides