18
Research on Carbon Dioxide
Carbon dioxide, CO 2 , is a compound of special interest in the history of chemistry.
Long before the discussions on global warming, carbon dioxide was a highly
controversial substance [1]. It was studied already by Johannes Baptista van
Helmont (1580–1644), who coined the word gas and prepared carbon dioxide by
several different methods. It was probably the first gas other than air to be
described, although van Helmont did not realise that the carbon dioxide prepared by
different methods actually was the same gas.
In aqueous solution, carbon dioxide is in equilibrium with carbonic acid, a weak,
unstable acid that cannot be isolated:
CO 2 ðaqÞ þ H 2 OðlÞ H 2 CO 3 ðaqÞ:
Water saturated with carbon dioxide is only weakly acidic. At ambient temperature and pressure, water saturated with carbon dioxide contains only 0.17%
carbon dioxide, of which less than 1% in the form of carbonic acid.
It was early recognised that gas was formed by fermentation and by addition of
acids to carbonates, such as limestone (CaCO 3 ), potash (K 2 CO 3 ) and soda
(Na 2 CO 3 ), e.g.
CaCO 3 ðsÞ þ H 2 SO 4 ðlÞ ! CaSO 4 ðsÞ þ H 2 OðlÞ þ CO 2 ðaqÞ:
Carbon dioxide was also expelled by heating limestone (CaCO 3 ) to produce
quicklime (CaO):
CaCO 3 ðsÞ ! CaOðsÞ þ CO 2 ðgÞ:
Calcium oxide (quicklime) and calcium hydroxide (Ca(OH) 2 ; slaked lime),
obtained from calcium oxide and water, readily absorb CO 2 from the atmosphere to
reform calcium carbonate. This is the reaction occurring as mortar hardens, a
process used for centuries. It was first believed that limestone absorbed fire to give
© Springer Nature Switzerland AG 2020
A. Lennartson, Carl Wilhelm Scheele and Torbern Bergman, Perspectives on the
History of Chemistry, https://doi.org/10.1007/978-3-030-49194-9_18
245
Research on Carbon Dioxide
Carbon dioxide, CO 2 , is a compound of special interest in the history of chemistry.
Long before the discussions on global warming, carbon dioxide was a highly
controversial substance [1]. It was studied already by Johannes Baptista van
Helmont (1580–1644), who coined the word gas and prepared carbon dioxide by
several different methods. It was probably the first gas other than air to be
described, although van Helmont did not realise that the carbon dioxide prepared by
different methods actually was the same gas.
In aqueous solution, carbon dioxide is in equilibrium with carbonic acid, a weak,
unstable acid that cannot be isolated:
CO 2 ðaqÞ þ H 2 OðlÞ H 2 CO 3 ðaqÞ:
Water saturated with carbon dioxide is only weakly acidic. At ambient temperature and pressure, water saturated with carbon dioxide contains only 0.17%
carbon dioxide, of which less than 1% in the form of carbonic acid.
It was early recognised that gas was formed by fermentation and by addition of
acids to carbonates, such as limestone (CaCO 3 ), potash (K 2 CO 3 ) and soda
(Na 2 CO 3 ), e.g.
CaCO 3 ðsÞ þ H 2 SO 4 ðlÞ ! CaSO 4 ðsÞ þ H 2 OðlÞ þ CO 2 ðaqÞ:
Carbon dioxide was also expelled by heating limestone (CaCO 3 ) to produce
quicklime (CaO):
CaCO 3 ðsÞ ! CaOðsÞ þ CO 2 ðgÞ:
Calcium oxide (quicklime) and calcium hydroxide (Ca(OH) 2 ; slaked lime),
obtained from calcium oxide and water, readily absorb CO 2 from the atmosphere to
reform calcium carbonate. This is the reaction occurring as mortar hardens, a
process used for centuries. It was first believed that limestone absorbed fire to give
© Springer Nature Switzerland AG 2020
A. Lennartson, Carl Wilhelm Scheele and Torbern Bergman, Perspectives on the
History of Chemistry, https://doi.org/10.1007/978-3-030-49194-9_18
245