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Chlorine

Cl2, 70.906 g/mol. Its structure, the values that were measured, the values that were calculated, and where each one came from.

verified recordInorganic compound5 measured properties

Drawn from the SMILES. It shows how the atoms are connected — not a photograph of a molecule, and not its shape in space.

Identifiers

Molecular formula
Cl₂
Molecular weight
70.906 g/mol
Exact mass
69.937705 g/mol
IUPAC name
molecular chlorine
SMILES
ClCl
InChI
InChI=1S/Cl2/c1-2
InChIKey
KZBUYRJDOAKODT-UHFFFAOYSA-N

Both are open without an account.

Measured properties

Values somebody obtained from a sample and published. Where two sources report the same property they are both shown, in the units each used — a disagreement between them is information, and averaging it away would be inventing a number neither one gave.

Boiling Point
-30.3 °F at 760 mmHg (EPA, 1998)measured · CAMEO Chemicals
-34.04 °Cmeasured · Hazardous Substances Data Bank (HSDB)
Melting Point
-150 °F (EPA, 1998)measured · CAMEO Chemicals
-101.5 °Cmeasured · Hazardous Substances Data Bank (HSDB)
Density
1.424 at 59 °F (pressurized liquid) (USCG, 1999) - Denser than water; will sinkmeasured · CAMEO Chemicals
2.898 g/Lmeasured · Hazardous Substances Data Bank (HSDB)
Solubility
0.7 % (NIOSH, 2024)measured · CAMEO Chemicals
1.46 g/100 cc water at 0 °C; 310 cc/100 cc water at 10 °C; 177 cc/100 cc water at 30 °C; 0.57 g/100 cc water at 30 °Cmeasured · Hazardous Substances Data Bank (HSDB)
Vapor Pressure
7600 mmHg at 86 °F (EPA, 1998)measured · CAMEO Chemicals
5.83X10+3 mm Hg at 25 °Cmeasured · Hazardous Substances Data Bank (HSDB)

Calculated properties

Derived from the structure rather than from a sample. These are reproducible and they are not measurements: a calculated partition coefficient and a measured one can differ by a long way, and where both exist they are listed apart on purpose.

Molecular weight
70.9 g/molcalculated · reference compound database
Average mass of one molecule, from reference compound database.
Exact mass
69.9377054 Dacalculated · reference compound database
Mass of the most common isotopic form.
XLogP3
1.6calculated · reference compound database
Estimated oil/water partition, computed by reference compound database.
Polar surface area
0 Ųcalculated · reference compound database
Polar surface area as computed by reference compound database.
Complexity
0calculated · reference compound database
A rough measure of how intricate the structure is.
H-bond donors
0calculated · reference compound database
H-bond acceptors
0calculated · reference compound database
logP
1.379calculated · chemistry engine
Estimated preference for oil over water. Higher means more oil-like.
Topological polar surface area
0 Ųcalculated · chemistry engine
Surface area from polar atoms; relates to how easily a molecule crosses membranes.
H-bond donors
0calculated · chemistry engine
Atoms that can donate a hydrogen bond.
H-bond acceptors
0calculated · chemistry engine
Atoms that can accept a hydrogen bond.
Rotatable bonds
0calculated · chemistry engine
Single bonds the molecule can freely twist around.
Molar refractivity
11.706 cm³/molcalculated · chemistry engine
Relates to the molecule's polarisability.
Fraction sp³ carbons
0calculated · chemistry engine
Share of carbon atoms with tetrahedral bonding.
QED drug-likeness
0.4043calculated · chemistry engine
Quantitative estimate of drug-likeness (0–1).

What it is made of

Elements

Percentages are of the molecular weight above, worked out the same way the molar mass calculator does it.

Structure

Heavy atoms, hydrogen excluded
2
Total atoms, hydrogen included
2
Rings
0
Aromatic rings
0
Stereocentres
0
Formal charge
0

The molecule in three dimensions

Rotate and inspect the atoms. Loaded only when you ask, so the page stays light.

The drawing above is a diagram of what is bonded to what. A molecule is not flat, and the model here is one low-energy shape generated from the connectivity — useful for seeing which groups can reach each other, and not a measured structure. A real sample is a population of conformations, interconverting.

Reactions it appears in

No documented reaction with a written procedure and a source involves Chlorine yet.

Other names for it

The systematic name on this record is molecular chlorine.

The sources also call it Molecular chlorine, dichlorine, Bertholite, Chlorine gas, Chlorinum, Chloor, Chlore, Chlor, Cloro, Chlorine mol., Chlorine 35.

Structurally related

Nothing structurally close to Chlorine has a page here yet.

Where these values came from

compound record.

What this page does not claim

The identifiers are what the source record holds, copied rather than recomputed. Measured values are reported as their source gave them, units and all; calculated values are marked as calculated and are not measurements. Where a field is absent the page says so, because a blank cell reads as a zero and a guessed value reads as a fact.

Nothing here is a hazard assessment, a purity statement or advice about handling a sample. A flash point quoted from a safety database is a number somebody published, not a judgement by us about whether this molecule is safe for what you intend.