engineering

Lithium bromide

Lithium bromide is a engineering 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 Lithium bromide rather than just read about it. In short: Lithium bromide (LiBr) is a chemical compound of lithium and bromine. Its extreme hygroscopic character makes LiBr useful as a desiccant in certain air conditioning systems.

Key takeaways

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

Reference excerpt

Lithium bromide (LiBr) is a chemical compound of lithium and bromine. Its extreme hygroscopic character makes LiBr useful as a desiccant in certain air conditioning systems.

Production and properties

LiBr is prepared by treating an aqueous suspension of lithium carbonate with hydrobromic acid or by reacting lithium hydroxide with bromine. It forms several crystalline hydrates, unlike the other alkali metal bromides. Lithium hydroxide and hydrobromic acid (aqueous solution of hydrogen bromide) will precipitate lithium bromide in the presence of water.

LiOH + HBr → LiBr + H2O

Uses A 50–60% aqueous solution of lithium bromide is used in air-conditioning systems as desiccant. It is also used in absorption chilling along with water (see absorption refrigerator). Solid LiBr is a useful reagent in organic synthesis. It is included into oxidation and hydroformylation catalysts; it is also used for deprotonation and dehydration of organic compounds containing acidic protons, and for the purification of steroids and prostaglandins.

Medical applications Lithium bromide was used as a sedative beginning in the early 1900s, but it fell into disfavor in the 1940s as newer sedatives became available and when some heart patients died after using the salt substitute lithium chloride. Like lithium carbonate and lithium chloride, it was used as treatment for bipolar disorder.

Hazards Lithium salts are psychoactive and somewhat corrosive. Heat is quickly generated when lithium bromide is dissolved into water because it has a negative enthalpy of solution.

References

Cited sources Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. ISBN 9781498754293.

External links

"A PDF file from GFS Chemicals, a supplier of lithium bromide" (PDF). Archived from the original (PDF) on 2006-03-16. Retrieved 2005-09-15.

Illustrations

Worked examples

Example 1 — a first encounter with Lithium bromide

Start with the simplest possible case. Write down what Lithium bromide claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, 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 Lithium 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 Lithium 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 Lithium bromide

In research: Lithium bromide appears in engineering 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 Lithium 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: Lithium bromide is common in secondary-school and first-year university syllabi. It links to neighbouring topics Alkali metal bromides, Bromides, GABAA receptor positive allosteric modulators, so understanding it makes those chapters shorter.
In everyday life: Look for Lithium 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 Lithium bromide in 20 minutes

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

Frequently asked questions

What is Lithium bromide in simple terms?

Lithium bromide (LiBr) is a chemical compound of lithium and bromine. Its extreme hygroscopic character makes LiBr useful as a desiccant in certain air conditioning systems.

Why does Lithium bromide matter?

Because it connects several engineering 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 Lithium 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 Lithium bromide.