Hydroquinone

Hydroquinone ;
Names:	hydroquinone; para-dihydroxybenzene; benzene-1,4-diol; 1,4-benzenediol; 1,4-dihydroxybenzene; quinol;
Formula:	C6H4(OH)2;
Molar mass:	110.112 g/mol;
Density:	1.358 g/cm3 (α-form); 1.325 g/cm3 (γ-form);
Crystal system:	monoclinic (γ-form); a=8.07 Å, b=5.2 Å, c=13.2 Åα=90°, β=107°, γ=90°;
Shapes:	https://en.crystalls.info/w/uploads/media/a/ab/Trigonal_prism.json Trigonal prism https://en.crystalls.info/w/uploads/media/5/52/Needle.json Needle ;
Color:	colorless; white;
Melting point:	173.8 °C446.95 K <br />344.84 °F <br />804.51 °R <br /> (α-form); 169 °C442.15 K <br />336.2 °F <br />795.87 °R <br /> (γ-form);
Boiling point:	287 °C560.15 K <br />548.6 °F <br />1,008.27 °R <br />;
Magnetic properties:	diamagnetic; χ=-6.46 · 10-5cm³/mol;
Stability:	stable;
Hardness:	fragile;
Toxicity:	moderately toxic; LD50=490mg/kg

Description

Organic compound, simple diactomic aromatic alcohol. Doesn't form water hydrates.

Can be bought in photography supplies store (component of old photographic developers).

Can form clathrates, e.g. with methanol, sulfur dioxide, hydrogen sulfide and other compounds

Rapidly oxidizes by oxygen in the air, changing color of solution and crystals to dark-brown

TableGraph

Phenols
Ethylvanillin (C₉H₁₀O₃) • Hydroquinone (C₆H₄(OH)₂) • Paracetamol (C₈H₉NO₂) • Vanillin (C₈H₈O₃) • Phenol (C₆H₅OH)

Hydroquinone
Names:	hydroquinone para-dihydroxybenzene benzene-1,4-diol 1,4-benzenediol 1,4-dihydroxybenzene quinol
Formula:	C₆H₄(OH)₂
Molar mass:	110.112 g/mol
Density:	1.358 g/cm³ (α-form) 1.325 g/cm³ (γ-form)
Crystal system:	monoclinic (γ-form) a=8.07 Å, b=5.2 Å, c=13.2 Åα=90°, β=107°, γ=90°
Shapes:	Trigonal prism Needle
Color:	colorless white
Melting point:	173.8 °C446.95 K <br />344.84 °F <br />804.51 °R <br /> (α-form) 169 °C442.15 K <br />336.2 °F <br />795.87 °R <br /> (γ-form)
Boiling point:	287 °C560.15 K <br />548.6 °F <br />1,008.27 °R <br />
Magnetic properties:	diamagnetic χ=-6.46 · 10^-5cm³/mol
Stability:	stable
Hardness:	fragile
Toxicity:	moderately toxic LD₅₀=490mg/kg