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The Periodic Table

The Halogens - Reaction with Hydrogen.

How do the Halogens React with Hydrogen?

The halogens will react with hydrogen to form hydrogen halides.

How does Chlorine React with Hydrogen?

Hydrogen will react with chlorine to form hydrogen chloride.

hydrogen  +  chlorine      hydrogen chloride.
H_2(g)  +     Cl_2(g)                 2HCl_(g)

For the properties of HCl_(g) see the test for HCl gas.
For the structure of HCl_(g) see the structure of HCl.

Hydrogen chloride is very, very soluble in water.
For hydrogen chloride to be dissolved safely in water
an inverted funnel is used.
Hydrogen chloride dissolves to form hydrochloric acid.

hydrogen chloride + water    hydroxonium ion + chloride ion.
HCl_(g)       +       H₂O_(l)            H₃O⁺_(aq)    +      Cl^-_(aq)

The hydroxonium ion, H₃O⁺, (often written just as H⁺, hydrogen ion)
is an acid in water - see acids.
H⁺  +  Cl^-  in water is hydrochloric acid.

All the hydrogen halides dissolved in water make acidic solutions
because they all produce hydrogen ions.

hydrogen bromide + water    hydroxonium ion + bromide ion.
HBr_(g)         +     H₂O_(l)             H₃O⁺_(aq)     +      Br^-_(aq)

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