science

Oxygen clathrate

Oxygen clathrate is a science 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 Oxygen clathrate rather than just read about it. In short: Oxygen clathrate or oxygen hydrate is a clathrate hydrate consisting of a water-ice framework with regular crystalline cavities that contain oxygen (O2) molecules. It has been proposed to occur naturally in the surface and near-surface ices of oxygen-atmosphere icy moons such as Europa and Ganymede, where the oxygen is thought to originate from radiolysis of water ice by charged particles.

Key takeaways

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

Reference excerpt

Oxygen clathrate or oxygen hydrate is a clathrate hydrate consisting of a water-ice framework with regular crystalline cavities that contain oxygen (O2) molecules. It has been proposed to occur naturally in the surface and near-surface ices of oxygen-atmosphere icy moons such as Europa and Ganymede, where the oxygen is thought to originate from radiolysis of water ice by charged particles.

Structure At low pressure, oxygen clathrate adopts the cubic CS-II (also called sII) clathrate structure, with two distinct cage types: 16 smaller dodecahedral (12-faced) cages and 8 larger hexakaidecahedral (16-faced) cages per unit cell, first characterized by neutron powder diffraction. As with hydrogen clathrate, multiple oxygen molecules can occupy the larger cage, with occupancy increasing from about 1 O2 per large cage at low pressure to as many as 2.8 O2 per cage near 1.4 GPa. Under pressure at room temperature, oxygen clathrate undergoes a sequence of structural transformations before decomposing into ice and free oxygen:

CS-II clathrate (stable from ambient pressure to about 1.0 GPa) a tetragonal ST clathrate structure (about 1.0–1.2 GPa), also observed in the argon–water and nitrogen–water systems a chiral C0 hydrate structure (about 1.2–1.6 GPa), in which oxygen occupies open channels in a water network unrelated to any stable ice phase, also seen in the hydrogen–water and carbon dioxide–water systems a filled ice phase isostructural with methane hydrate III (about 1.6–2.6 GPa), in which oxygen occupies channels within a water framework resembling ice Ih Above 2.6 GPa at room temperature, this filled-ice phase decomposes into separate oxygen and ice VII. This decomposition pressure is low compared to other filled-ice gas hydrates: hydrogen-filled ice remains stable to at least 90 GPa and methane-filled ice to at least 150 GPa. At low temperature (66 K), representative of icy-moon surface conditions, the CS-II clathrate remains stable up to about 1.4 GPa, above which the host lattice undergoes pressure-induced amorphization rather than a further ordered structural transition.

Occurrence and planetary relevance Oxygen has been detected spectroscopically on the surface of Ganymede, where it is thought to be held largely as a low-pressure clathrate, and oxygen clathrates have been proposed as a component of subsurface ices on Europa. Because oxygen hydrate is stable to at least 2.6 GPa, it can in principle penetrate to depths within icy moons both above and below any subsurface liquid-water ocean. Oxygen and hydrogen clathrates share structural similarities, both forming CS-II and C0 phases with multiple guest occupancy of the larger cage. Since both O2 and H2 are produced together by radiolysis of water ice, their preferential retention in close proximity within a shared host lattice has been proposed as a mechanism for enhanced recombination back into water, offering a possible explanation for the discrepancy between modelled and measured rates of oxygen production on Europa.

See also filled ice Hydrogen clathrate Nitrogen clathrate Methane clathrate Clathrate hydrate Europa (moon)

References

Worked examples

Example 1 — a first encounter with Oxygen clathrate

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

In research: Oxygen clathrate appears in science 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 Oxygen clathrate 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: Oxygen clathrate is common in secondary-school and first-year university syllabi. It links to neighbouring topics Clathrates, Hydrates, Oxygen, so understanding it makes those chapters shorter.
In everyday life: Look for Oxygen clathrate 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 Oxygen clathrate in 20 minutes

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

Frequently asked questions

What is Oxygen clathrate in simple terms?

Why does Oxygen clathrate matter?

Because it connects several science 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 Oxygen clathrate?

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 Oxygen clathrate.