chemistry

Lithium peroxide

Lithium peroxide 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 Lithium peroxide rather than just read about it. In short: Lithium peroxide is the inorganic compound with the formula Li2O2. Lithium peroxide is a white solid, and unlike most other alkali metal peroxides, it is nonhygroscopic.

Key takeaways

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

Reference excerpt

Lithium peroxide is the inorganic compound with the formula Li2O2. Lithium peroxide is a white solid, and unlike most other alkali metal peroxides, it is nonhygroscopic. Because of its high oxygen:mass and oxygen:volume ratios, the solid has been used to remove CO2 from and release O2 to the atmosphere in spacecraft.

Preparation It is prepared by the reaction of hydrogen peroxide and lithium hydroxide. This reaction initially produces lithium hydroperoxide:

LiOH + H2O2 → LiOOH + H2O This lithium hydroperoxide may exist as lithium peroxide monoperoxohydrate trihydrate (Li2O2·H2O2·3H2O). Dehydration of this material gives the anhydrous peroxide salt:

2 LiOOH → Li2O2 + H2O2 Li2O2 decomposes at about 450 °C to give lithium oxide:

2 Li2O2 → 2 Li2O + O2 The structure of solid Li2O2 has been determined by X-ray crystallography and density functional theory. The solid features eclipsed "ethane-like" Li6O2 subunits with an O-O distance of around 1.5 Å.

Uses

Air purification It is used in air purifiers where weight is important, e.g., spacecraft or other sealed spaces and apparatuses to absorb carbon dioxide and release oxygen in the reaction: Li2O2 + CO2 → Li2CO3 + 1⁄2 O2 Similar to the reaction of lithium hydroxide with carbon dioxide to release 1 Li2CO3 and 1 H2O, lithium peroxide has high absorption capacity and absorbs more CO2 than does the same weight of lithium hydroxide and offers the bonus of releasing oxygen instead of water.

Styrene polymerization Lithium peroxide can also act as a catalyst for polymerization of styrene to polystyrene. The polymerization of styrene to polystyrene typically involves the use of radical initiators via the free radical chain mechanism but lithium peroxide can also initiate radical polymerization reactions under certain conditions, although not as widely used.

Lithium-air battery The reversible lithium peroxide reaction is the basis for a prototype lithium–air battery. Using oxygen from the atmosphere allows the battery to eliminate storage of oxygen for its reaction, saving battery weight and size.

See also Lithium oxide Lithium monoxide anion

References

External links WebElements entry

Illustrations

Worked examples

Example 1 — a first encounter with Lithium peroxide

Start with the simplest possible case. Write down what Lithium peroxide 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 Lithium peroxide 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 peroxide 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 peroxide

In research: Lithium peroxide 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 Lithium peroxide 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 peroxide is common in secondary-school and first-year university syllabi. It links to neighbouring topics Lithium compounds, Oxidizing agents, Peroxides, so understanding it makes those chapters shorter.
In everyday life: Look for Lithium peroxide 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 peroxide in 20 minutes

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

Frequently asked questions

What is Lithium peroxide in simple terms?

Lithium peroxide is the inorganic compound with the formula Li2O2. Lithium peroxide is a white solid, and unlike most other alkali metal peroxides, it is nonhygroscopic.

Why does Lithium peroxide 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 Lithium peroxide?

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 peroxide.