Nitrogen compounds

The lone pair of electrons on the nitrogen can accept a H+ ion to form an an ammonium salt.

• Mono-basic: The NH₂ accepts the H+ ion to form NH₃+. The negitively charged part of the acid then forms an ionic bond. e.g. CH₃NH₃+Cl- • Di-basic: 2 moles of the reactant amine are needed. An ionic bond between the NH₃+ and the negitive ion from the acid is formed. 2 moles of the product salt are also formed. e.g. (CH₃NH₃+)₂SO₄²⁻ • Tri-basic. 3 moles of the reactant amine are needed. An ionic bond between the NH₃+ and the negitive ion from the acid is formed. 3 moles of the product salt are also formed. e.g. (CH₃NH₃+)₃PO₄³⁻

The avalibility of the lone pair to accept a H+ ion

Aromatic amines. The lone pair on the nitrogen delocalises into the ring, making the lone pair very inaccessible.

Ammonia. There is no aromatic ring so the lone pair can’t delocalise, making it avalible.

Amines with a carbon chain. The carbon chain pushes the electrons towards the nitrogen, making them readily avalible.

• Excess ammonia, dissolved in ethanol, reacts with a haloalkane to form to form an ammonium-halogeno salt. • The amine is then formed from this salt. The salt is reacted with NaOH to form the amine. The halogen reacts with the sodium to form an ionic compound. • The OH from the hydroxide reacts with the H+ released by the NH₃+ to make water. CH₃Cl + :NH₃ -> CH₃NH₃+Cl- CH₃NH₃+Cl- + NaOH -> CH₃NH₂ + NaCl + H₂O The equations above are for forming a primary amine. When forming a secondary or tertiary amine, the amine itself replaces the haloalkane.

• The reduction of nitrobenzene. • Concentrated hydrochloric acid, tin catalyst and reflux • 6 [H] is needed to balance the equation • 2 moles of water are also formed

RCH(NH₂)COOH

At the isoelectric point, the amino acid reacts with itself. The H on the OH bonds to the nitrogen. The nitrogen gains a + charge, the oxygen gains a - charge.

The pH at which an amino acid can act as a zwitterion

• When the pH decreases, more H+ ions are avaliable. • Hydrogens are added to the molecule. Any O- groups become OH groups. • Any COO- groups become COOH groups. • A positive ion is formed as the NH₃+ parts are unchanged.

• H+ ions are removed from the molecule. • Any NH₃+ groups become NH₂ groups. • Any COOH groups become COO- groups. • A negative ion is formed.

• Acid protonates the NH₂ group, forming an NH₃+ • The X- ion forms an ionic bond with the NH₃+, forming an ammounium salt

A carboxylate salt (COO- X+) and water is formed

• Ester and water • Condensation reaction

A carbon with 4 different groups bonded to it

Place 2 molecules over another and they are exactly the same

All amino acids have at least 1 chiral carbon

• Isomer 1-> Isomer 2 is a full mirror image of isomer 1 • Isomer 2 -> Isomer 3 is a mirror image of the top carbon in isomer 1. Keep the bottom carbon the same as isomer 1. • Isomer 3 -> Isomer 4 is a mirror image of the bottom carbon in isomer 1. Keep the top carbon the same as isomer 1.

When small molecules join together to form a larger molecule with the loss of another small molecule (H₂O or HCL)

RCOOR

• 1 monomer, with both a COOH/COCl and OH group • 2 monomers, with both a di-carboxylic acid OR di-acyl chloride and a diol

(2n-1) H₂O