What are the applications of displacement reactions?

1 Answer
Apr 12, 2014

Some applications of displacement reactions are thermite welding, steel making, extraction of metals, and relief from acid indigestion.

Explanation:

A single displacement reaction is often of the type

#"A + BC → B + AC"#

In this reaction, element #"A"# replaces element #"B"# in the compound #"BC"#.

Here are a few examples of the practical applications of displacement reactions.

Thermite Welding

A mixture of #"Al"# and #"Fe"_2"O"_3# reacts to produce molten iron that is used to join railway rails together.

#"2Al" + "Fe"_2"O"_3 → "Al"_2"O"_3 + "2Fe"#

Al replaces #"Fe"# in #"Fe"_2"O"_3# to form #"Al"_2"O"_3#.

www.sec.gov

#"CADWELD"^®# process

A mixture of #"Al"# and #"CuO"# is used for creating electric joints between #"Cu"# and steel.

#"2Al" + "3CuO" → "3Cu" + "Al"_2"O"_3#

#"Al"# replaces #"Cu"# in the #"CuO"#.

www.nimbus-lightning.co.uk

Steel Making

We can extract iron from its ore (#"Fe"_2"O"_3#) by heating it with carbon in giant blast furnaces.

#"3C" + "2Fe"_2"O"_3 → "4Fe" + "3CO"_2#

#"C"# replaces #"Fe"# in #"Fe"_2"O"_3# to form #"CO"_2#.

www.chemguide.co.uk

Extraction of Metals

Heating a mixture of #"Cr"_2"O"_3# and finely divided #"C"# produces metallic chromium.

#"3C" + "2Cr"_2"O"_3 → "4Cr" + "3CO"_2#

#"C"# replaces #"Cr"# in #"Cr"_2"O"_3# to form #"CO"_2# and chromium metal.

Acid Indigestion

We can relieve the distress when the stomach produces too much #"HCl"# by drinking a solution of sodium hydrogen carbonate.

#"HCl" + "NaHCO"_3 → "NaCl" + "H"_2"CO"_3#

The #"H"# in the #"HCl"# displaces the #"Na"# in #"NaHCO"_3# to produce #"H"_2"CO"_3#.