RSC, Education in Chemistry, (May 2007) fabricated a mischievous and
mildly sensational argument to credit Nernst with the discovery of what was
to become known as the ‘Haber Process’. Predicated on being ‘the first to
synthesise ammonia at high pressure’ in his electric pressure oven, these
authors’ claims can be dismissed. Nernst’s oven existed simply to support his
‘Heat Theorem’, but the ‘Haber Process’ is universally accepted as forming
the basis of the industrial synthesis of ammonia. Later chapters will show that
‘Haber’s’ ‘process’ was a complex affair at the cutting edge of the understanding of technical gas reactions. Nernst’s apparatus made no pretensions
whatever to represent a ‘process’, nor even an application, a point which he
acknowledged in the discussion at Hamburg and which he later repeated
before the Patent courts in 1912 when he declared that his interest had been
of a ‘purely theoretical nature’. (See Chaps. 6, 12 and Dietrich Stoltzenberg,
Fritz Haber. Chemist, Noble Laureate, German, Jew. Chemical Heritage Press,
Philadelphia, Pennsylvania, (2004), p. 176.) Indeed, Chap. 6 shows that he
did not even achieve a correct equilibrium. If one wishes to meddle with
history, one should get one’s facts right. Authors would be better advised if
they referred to the ‘Haber Process’ for what it really was, the ‘Haber – Le
Rossignol’ process.
6. Kormos Barkan, Walther Nernst and the Transition to Modern Physical Science,
Cambridge University Press, (1999).
7. ‘Normal’ (N) solutions were in use at the time and even through to the
1960s. The concept of ‘normality’ rendered the calculations of volumetric
analysis very simple. Normality was centred around the idea of ‘equivalent
weight’. For example, a ‘normal’ (1 N) solution of sodium hydroxide contained the molecular weight of NaOH in grams (40.0 g) per litre, whilst a
‘normal’ (1 N) solution of hydrochloric acid also contained the molecular
weight of HCl in grams (36.5 g) per litre. One litre of 1 N NaOH therefore
reacted completely with one litre of 1 N HCl so that 40 g of NaOH was
equivalent to 36.5 g HCl. However, a 1 N solution of an acid such as sulphuric, contained just 49 g per litre, (half the molecular weight in grams)
since a 1 N solution of sulphuric acid would then react completely with a
1 N solution of say NaOH or NH 4 OH or NH 3 (aq). The ‘equivalent weight’
of sulphuric acid w.r.t these titrations was therefore just 49 g.
8. For an ‘ideal’ system, K p is independent of pressure.
9. Incidentally, even after all these years this equation has often been
mis-quoted in the literature. Poor type-setting in the original publication led
to the minus sign being incorporated into the quotient line, the first term
appearing as 24,000/4.571T i.e., +ve not −ve. As an example, see; p. 9,
J. R. Jennings, Catalytic Ammonia Synthesis: Fundamentals and Practice,
Springer, (1991).
124
D. Sheppard
mildly sensational argument to credit Nernst with the discovery of what was
to become known as the ‘Haber Process’. Predicated on being ‘the first to
synthesise ammonia at high pressure’ in his electric pressure oven, these
authors’ claims can be dismissed. Nernst’s oven existed simply to support his
‘Heat Theorem’, but the ‘Haber Process’ is universally accepted as forming
the basis of the industrial synthesis of ammonia. Later chapters will show that
‘Haber’s’ ‘process’ was a complex affair at the cutting edge of the understanding of technical gas reactions. Nernst’s apparatus made no pretensions
whatever to represent a ‘process’, nor even an application, a point which he
acknowledged in the discussion at Hamburg and which he later repeated
before the Patent courts in 1912 when he declared that his interest had been
of a ‘purely theoretical nature’. (See Chaps. 6, 12 and Dietrich Stoltzenberg,
Fritz Haber. Chemist, Noble Laureate, German, Jew. Chemical Heritage Press,
Philadelphia, Pennsylvania, (2004), p. 176.) Indeed, Chap. 6 shows that he
did not even achieve a correct equilibrium. If one wishes to meddle with
history, one should get one’s facts right. Authors would be better advised if
they referred to the ‘Haber Process’ for what it really was, the ‘Haber – Le
Rossignol’ process.
6. Kormos Barkan, Walther Nernst and the Transition to Modern Physical Science,
Cambridge University Press, (1999).
7. ‘Normal’ (N) solutions were in use at the time and even through to the
1960s. The concept of ‘normality’ rendered the calculations of volumetric
analysis very simple. Normality was centred around the idea of ‘equivalent
weight’. For example, a ‘normal’ (1 N) solution of sodium hydroxide contained the molecular weight of NaOH in grams (40.0 g) per litre, whilst a
‘normal’ (1 N) solution of hydrochloric acid also contained the molecular
weight of HCl in grams (36.5 g) per litre. One litre of 1 N NaOH therefore
reacted completely with one litre of 1 N HCl so that 40 g of NaOH was
equivalent to 36.5 g HCl. However, a 1 N solution of an acid such as sulphuric, contained just 49 g per litre, (half the molecular weight in grams)
since a 1 N solution of sulphuric acid would then react completely with a
1 N solution of say NaOH or NH 4 OH or NH 3 (aq). The ‘equivalent weight’
of sulphuric acid w.r.t these titrations was therefore just 49 g.
8. For an ‘ideal’ system, K p is independent of pressure.
9. Incidentally, even after all these years this equation has often been
mis-quoted in the literature. Poor type-setting in the original publication led
to the minus sign being incorporated into the quotient line, the first term
appearing as 24,000/4.571T i.e., +ve not −ve. As an example, see; p. 9,
J. R. Jennings, Catalytic Ammonia Synthesis: Fundamentals and Practice,
Springer, (1991).
124
D. Sheppard