chemistry

Nitrosyl bromide

Nitrosyl bromide is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Nitrosyl bromide rather than just read about it. In short: Nitrosyl bromide is the chemical compound with the chemical formula NOBr. It is a red gas with a condensation point just below room temperature.

Key takeaways

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

Reference excerpt

Nitrosyl bromide is the chemical compound with the chemical formula NOBr. It is a red gas with a condensation point just below room temperature. It reacts with water. Nitrosyl bromide can be formed by the reversible reaction of nitric oxide with bromine. This reaction is of interest as it is one of very few third-order homogeneous gas reactions. NOBr is prone to photodissociation at standard pressure and temperature.

2 NO + Br2 ⇌ 2 NOBr Another way to make it is by way of nitrogen dioxide reacting with potassium bromide.

2NO2 + KBr → BrNO + KNO3

Dissociation kinetics The bond breaking of the chemical can be done with photolysis using a light to separate the molecules that are present. Another to separate nitrosyl bromide into NO and Br or Br2 is by having excess of NO which then the experiment will follow first order kinetics. This reverse rate constant was calculated to be kr = 2.29 ± 0.33 x 10-21 cm3 /molecules With excess Br2 plus NO the reaction follows third order kinetics. Br2 + 2NO ↔ 2BrNO Some of the previous experiments that determined reaction rates were also done by Histatsune and Zafonte, Hippler, and Godfrey. Histatsune and Zafonte determined the forward and reverse reaction rate constants. Hippler studied the recombination of Br atoms after photolysis of less than 0.3 torr of Br2 at room temperate in the range of 1 - 100 atm. He also studied the 2 recombination of Br and NO in the presence of helium. Godfrey examined the kinetics of BrNO formation and destruction using time resolved photolysis techniques. He also included the effects of the loss of Br2 to internal surfaces of the cell in calculations of the reaction rate constants. The reaction rates were determined to be between the range of 1.32 ± 0.14 to 1.68 ± 0.11 x 10-38 cm6 /molecule2 -s for kf and from 2.09 ± 0.55 to 3.71 x 10-21 cm3 /molecule-s for kr. There was a rate constant found of kf = 1.56 ± 0.20 x 10-38 cm6 /molecule2 - s at 293 ± 1 K The third order reaction is the best reaction to show the formation of nitrosyl bromide. The third order reaction is rare to see with bond breaking reactions between stable molecules but there have been no experiments to prove that this experiment does not have any intermediate steps, but it is suspected that there is two steps.

Safety Precautions Nitrosyl bromide photodissociates to toxic chemicals (bromine and nitric oxide). The chemical or its decomposition products should not get into contact with skin or eyes. Breathing or wafting any of these chemicals towards oneself can endanger health.

Physical characteristics Nitrosyl bromide is a red gas at room temperate.

References

Footnotes

General sources Mahoney, Lori A., "The Kinetics Following Photolysis of Nitrosyl Bromide" (2004). Theses and Dissertations. 3719. https://scholar.afit.edu/etd/3719 C. M. Blair, P. D. Brass, D. M. Yost, The equilibrium between nitric oxide, bromine and nitrosyl bromide. Journal of the American Chemical Society. 56, 1916–1918 (1934)

External links Media related to Nitrosyl bromide at Wikimedia Commons

Illustrations

Worked examples

Example 1 — a first encounter with Nitrosyl bromide

Start with the simplest possible case. Write down what Nitrosyl bromide 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 Nitrosyl bromide 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 Nitrosyl bromide 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 Nitrosyl bromide

In research: Nitrosyl bromide 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 Nitrosyl bromide 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: Nitrosyl bromide is common in secondary-school and first-year university syllabi. It links to neighbouring topics Gases with color, Inorganic compound stubs, Nitrogen oxohalides, so understanding it makes those chapters shorter.
In everyday life: Look for Nitrosyl bromide 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.

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How to study Nitrosyl bromide in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Nitrosyl bromide 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.
Explain Nitrosyl bromide out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Nitrosyl bromide in simple terms?

Nitrosyl bromide is the chemical compound with the chemical formula NOBr. It is a red gas with a condensation point just below room temperature.

Why does Nitrosyl bromide 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 Nitrosyl bromide?

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 Nitrosyl bromide.