Nitrogen trichloride

Key takeaways

Nitrogen trichloride belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Nitrogen trichloride to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Nitrogen trichloride from memory before moving on to harder problems.

Reference excerpt

Nitrogen trichloride, also known as trichloramine, is the chemical compound with the formula NCl3. This yellow, oily, and explosive liquid is most commonly encountered as a product of chemical reactions between ammonia-derivatives and chlorine (for example, in swimming pools). Alongside monochloramine and dichloramine, trichloramine is responsible for the distinctive 'chlorine smell' associated with swimming pools, where the compound is readily formed as a product from hypochlorous acid reacting with ammonia and other nitrogenous substances in the water, such as urea from urine.

Preparation and occurrence The compound is generated by treatment of ammonium chloride with calcium hypochlorite. When prepared in an aqueous-dichloromethane mixture, the trichloramine is extracted into the nonaqueous phase. Intermediates in this conversion include monochloramine and dichloramine, NH2Cl and NHCl2, respectively. Nitrogen trichloride, trademarked as Agene, was at one time used to bleach flour, but this practice was banned in the United States in 1949 due to safety concerns.

Structure and properties Like ammonia, NCl3 is a pyramidal molecule. The N-Cl distances are 1.42 Å, and the Cl-N-Cl angles are 107°. Nitrogen trichloride can form in small amounts when public water supplies are disinfected with monochloramine, and in swimming pools by disinfecting chlorine reacting with urea in urine and sweat from bathers:

6 HClO + CO ( NH 2 ) 2 ⟶ CO 2 + 5 H 2 O + 2 NCl 3 {\displaystyle {\ce {6 HClO + CO(NH2)2 -> CO2 + 5 H2O + 2 NCl3}}}

Reactions and uses The chemistry of NCl3 has been well explored. It is moderately polar with a dipole moment of 0.6 D. The nitrogen center is basic but much less so than ammonia. It is hydrolyzed by hot water to release ammonia and hypochlorous acid.

NCl 3 + 3 H 2 O ⟶ NH 3 + 3 HOCl {\displaystyle {\ce {NCl3 + 3 H2O -> NH3 + 3 HOCl}}}

Concentrated samples of NCl3 can explode to give N2 and chlorine gas.

2 NCl 3 ⟶ N 2 + 3 Cl 2 {\displaystyle {\ce {2NCl3 -> N2 + 3Cl2}}}

In the presence of aluminium trichloride, NCl3 reacts with some branched hydrocarbons to produce, after a hydrolysis step, amines.

Safety Nitrogen trichloride can irritate mucous membranes — it is a lachrymatory agent, but has never been used as such. The compound (rarely encountered) is a dangerous explosive, being sensitive to light, heat, even moderate shock, and organic compounds. Pierre Louis Dulong first prepared it in 1812, and lost several fingers and an eye in two explosions. In 1813, an NCl3 explosion blinded Sir Humphry Davy temporarily, inducing him to hire Michael Faraday as a co-worker. They were both injured in another NCl3 explosion shortly thereafter.

See also List of food contamination incidents Nitrogen tribromide Nitrogen triiodide

References

Further reading Jander, J. (1976). "Recent Chemistry and Structure Investigation of Nitrogen Triiodide, Tribromide, Trichloride, and Related Compounds". Advances in Inorganic Chemistry. Advances in Inorganic Chemistry and Radiochemistry. 19: 1–63. doi:10.1016/S0065-2792(08)60070-9. ISBN 9780120236190.{{cite journal}}: CS1 maint: periodical has ISBN (link) Kovacic, P.; Lowery, M. K.; Field, K. W. (1970). "Chemistry of N-Bromamines and N-Chloramines". Chemical Reviews. 70 (6): 639–665. doi:10.1021/cr60268a002. Hartl, H.; Schöner, J.; Jander, J.; Schulz, H. (1975). "Die Struktur des Festen Stickstofftrichlorids (−125 °C)". Zeitschrift für Anorganische und Allgemeine Chemie. 413 (1): 61–71. doi:10.1002/zaac.19754130108. Cazzoli, G.; Favero, P. G.; Dal Borgo, A. (1974). "Molecular Structure, Nuclear Quadrupole Coupling Constant and Dipole Moment of Nitrogen Trichloride from Microwave Spectroscopy". Journal of Molecular Spectroscopy. 50 (1–3): 82–89. Bibcode:1974JMoSp..50...82C. doi:10.1016/0022-2852(74)90219-7. Bayersdorfer, L.; Engelhardt, U.; Fischer, J.; Höhne, K.; Jander, J. (1969). "Untersuchungen an Stickstoff–Chlor-Verbindungen. V. Infrarot- und RAMAN-Spektren von Stickstofftrichlorid". Zeitschrift für Anorganische und Allgemeine Chemie. 366 (3–4): 169–179. doi:10.1002/zaac.19693660308.

External links

OSHA - Nitrogen trichloride Nitrogen Trichloride - Health References

Illustrations

Worked examples

Example 1 — a first encounter with Nitrogen trichloride

Start with the simplest possible case. Write down what Nitrogen trichloride claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Nitrogen trichloride before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Nitrogen trichloride ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Nitrogen trichloride

In research: Nitrogen trichloride appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Nitrogen trichloride in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Nitrogen trichloride is common in secondary-school and first-year university syllabi. It links to neighbouring topics Explosive chemicals, Inorganic amines, Inorganic chlorine compounds, so understanding it makes those chapters shorter.
In everyday life: Look for Nitrogen trichloride outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Nitrogen trichloride in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Nitrogen trichloride means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
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Frequently asked questions

What is Nitrogen trichloride in simple terms?

Nitrogen trichloride, also known as trichloramine, is the chemical compound with the formula NCl3. This yellow, oily, and explosive liquid is most commonly encountered as a product of chemical reactions between ammonia-derivatives and chlorine (for example, in swimming pools).

Why does Nitrogen trichloride matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Nitrogen trichloride?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Nitrogen trichloride.