- \usepackage{mhchem}
- \usepackage{chemfig}
- \usepackage{tabularx}
+- \usepackage{gensymb}
---
# Organic Chemistry
Carboxylic acids & \ce{-COOH} & \chemfig{{\color{blue}R}-C(=[:-30]O)-[:30]O-H}\\\hline
Ethers & \ce{-O-} & \chemfig{{\color{blue}R}-[:210]O-[:-30]{\color{blue}R}}\\\hline
Amines & \ce{-NH2} & \chemfig{{\color{blue}R}-N(-[:-30]H)(-[:30]H)}\\\hline
- Amides & \ce{-CONH2} & \chemfig{{\color{blue}R}-[:30]C(=[:90]O)-[:-30]N(-[:30]H)(-[:-30]H)}\\\hline
+ Amides & \ce{CO-NH} & \chemfig{{\color{blue}R}-[:30]C(=[:90]O)-[:-30]N(-[:30]H)(-[:-30]H)}\\\hline
\end{tabularx}
## Isomers
-* **Structural isomers** - same molecular formula, different arrangement
+* **Structural isomers** - same molecular formula, different arrangement
+- **Positional isomers** - different position of functional group (affects polarity)
+- **Chain isomers** - affects boiling point (more branches $implies$ lower boiling point)
* **Stereoisomers** - same structural configuration, different orientation
- * **Opotical isomers** - chiral centre, 4 groups bonded to C, non-superimposable mirror image
+ * **Optical/chiral isomers (enantiomers)** - chiral centre, 4 groups bonded to C, non-superimposable mirror image. Racemic mixture: 50/50 of each enantiomer. Affects optical polarity of light.
* **Geometric isomers** - \ce{C=C} double bond, 2 groups bonded to carbon atoms
- + **Cis** - same horizontal plane
- + **Trans** - diagonal
+ + **Cis** - same horizontal plane (symmetrical)
+ + **Trans** - diagonal (asymmetrical)
+
+### Chiral molecules
+
+- Not superimposable
+- Four different groups on C atom
+- Also called enantiomers
\begin{center}\setlength\tabcolsep{1cm}
\begin{tabularx}{0.5\textwidth}{cc}
\chemfig{[:60]{\text{\color{blue}R$^\prime$}}-C(-[:120]{\text{\color{red}R}})=[0]C(-[:-60]{\text{\color{red}R}})-[:60]{\text{\color{blue}R$^\prime$}}}
\end{tabularx}\end{center}
+## Flash point
+
+Lowest temperature at which the liquid gives off enough vapour to be ignited. Flammable $\implies$ flash point < 37.8 \degree C.
+
+## Reactions
+
+**Cracking** - split moluecules with heat/pressure/catalyst
+
+### Alkanes
+
+- Relatively inert
+- Non-polar solvent
+- Non-soluble in \ce{H2O}
+- Combusts in \ce{O2} (forms \ce{CO2 + H2O})
+- Reacts with halogens (**substitution** of \ce{H})
+
+### Alkenes
+
+- More reactive than alkanes
+- **Addition reactions**: \ce{C=C} bond is broken (energy released)
+- **Addition polymerisation**
+
+### Alcohols
+
+- Can be formed from haloalkane substitution reaction
+- **Oxidation** (combustion)
+- Oxidation state $\propto$ no. of atoms connected to \ce{C}
+- **Substitution** of functional group, e.g. \ce{ROH + NH3 -> RNH2 + H2O}
+- Primary alcohols oxidise to aldehydes then carboxylic acids
+- Secondary alcohols oxidise to ketones
+
+### Carboxylic acids
+
+- Weak acids
+- **Hydrolysis**: \ce{RCOOH + H2O <=> RCOO^{-} + H2O^{+}}
+- Rxn with amines - carboxylic acid + amine $\rightarrow$ ammonium salt $\rightarrow$ amide + water
+
+### Esterification
+
+- **Condensation reactions** (esterification): \ce{RCOOH + R^{$\prime$}OH -> RCOOR^{$\prime$} + H2O}
+- This is reversed by **hydrolysis**: ester + water $\rightarrow$ carboxylic acid + alcohol
+- Polyesters
+
+## Summary of reactions
+
+\textbf{Combustion:} \ce{C_{$x$} H_{$y$} + $z$O2 -> $x$CO2 + {$\dfrac{y}{2}$} H2O} \quad where $z=x+\dfrac{y}{4}$
+
+\textbf{Substitution:} e.g. halogenation/chlorination, catalysed by UV (alkanes) or compounds (alcohols etc.) which creates free radicals (unpaired e-)
+
+\textbf{Addition:} \ce{C=C} bond is broken, catalyst is required
+
+\textbf{Addition polymerisation:} uses addition to form a polymer
+
+\textbf{Condensation polymerisation:} produces \ce{H2O}
+
+\textbf{Oxidation:} occurs in alcohols to form aldehydes with catalysts \ce{H+/MnO4- (aq)} or \ce{H+/Cr2O7{2-} (aq)} - see combustion equation
+
+\textbf{Cracking:} heat/pressure/catalyst to break molecules