gcsescience.com                                       29                                       gcsescience.com

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   arrow   hydrogen chloride.
H2(g)  +     Cl2(g)    arrow             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  arrow  hydroxonium ionchloride ion.
HCl(g)       +       H2O(l)  arrow          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  arrow  hydroxonium ionbromide ion.
HBr(g)         +     H2O(l)   arrow          H3O+(aq)     +      Br-(aq)

back       Links       The Halogens       Revision Questions       next

gcsescience.com    The Periodic Table    Index    Periodic Table Quiz    gcsescience.com

Home      GCSE Chemistry      GCSE Physics

Copyright © 2015 gcsescience.com. All Rights Reserved.