// Workers AI · dad joke modeWhy was pyridinium chloride sad? It was feeling charged.

Pyridinium chloride

Pyridinium chloride The chemical structure of pyridinium chloride
Names
IUPAC name Pyridinium chloride
Other names Pyridine hydrochloride
Identifiers
CAS Number	628-13-7 Y
3D model (JSmol)	Interactive image
ChemSpider	62609
ECHA InfoCard	100.010.026
EC Number	211-027-4
PubChem CID	69401
UNII	1U87419851 Y
CompTox Dashboard (EPA)	DTXSID6027262
InChI InChI=1S/C5H5N.ClH/c1-2-4-6-5-3-1;/h1-5H;1H Key: AOJFQRQNPXYVLM-UHFFFAOYSA-N
SMILES C1=CC=[NH+]C=C1.[Cl-]
Properties
Chemical formula	C5H6ClN
Molar mass	115.56 g·mol−1
Appearance	Hygroscopic white crystals
Density	1.34 g/cm3
Melting point	144 °C (291 °F; 417 K)
Boiling point	Decomposes
Solubility in water	85 g / 100 mL
Solubility	Soluble in chloroform, ethanol, insoluble in diethyl ether
Vapor pressure	1 (0 °C)
Acidity (pKa)	5
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Irritant
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H312, H315, H319, H332, H335
Precautionary statements	P261, P264, P270, P271, P280, P301+P312, P302+P352, P304+P312, P304+P340, P305+P351+P338, P312, P321, P330, P332+P313, P337+P313, P362, P403+P233, P405, P501
NFPA 704 (fire diamond)	2 0 0
Flash point	Non-flammable
Autoignition temperature	Non-flammable
Lethal dose or concentration (LD, LC):
LD50 (median dose)	1600 mg/kg (oral, rat)
Safety data sheet (SDS)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Pyridinium chloride is an organic chemical compound with a formula of C₅H₅NHCl.

Preparation

Pyridinium chloride can be produced by passing hydrogen chloride in pyridine dissolved in diethyl ether, from which it precipitates:

C₅H₅N + HCl → C₅H₆N⁺Cl⁻ ↓

Acidity

Containing a pyridinium ion, pyridinium chloride has a pK_a of approximately 5, slightly more acidic than that of typical amines. This is due to the hybridization of the nitrogen: the nitrogen is sp² hybridized and more electronegative than those nitrogens in ammonium cations, which are sp³ hybridized. Hence they are stronger acids than amines and can be more easily deprotonated by bases.