chemistry

Plutonium compounds

Plutonium compounds 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 Plutonium compounds rather than just read about it. In short: Plutonium compounds are compounds containing the element plutonium (Pu). At room temperature, pure plutonium is silvery in color but gains a tarnish when oxidized.

Key takeaways

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

Reference excerpt

Plutonium compounds are compounds containing the element plutonium (Pu). At room temperature, pure plutonium is silvery in color but gains a tarnish when oxidized. The element displays four common ionic oxidation states in aqueous solution and one rare one:

Pu(III), as Pu3+ (blue lavender) Pu(IV), as Pu4+ (yellow brown) Pu(V), as PuO+2 (light pink) Pu(VI), as PuO2+2 (pink orange) Pu(VII), as PuO3−5 (green)-the heptavalent ion is rare. The color shown by plutonium solutions depends on both the oxidation state and the nature of the acid anion. It is the acid anion that influences the degree of complexing—how atoms connect to a central atom—of the plutonium species. Additionally, the formal +2 oxidation state of plutonium is known in the complex [K(2.2.2-cryptand)] [PuIICp″3], Cp″ = C5H3(SiMe3)2. A +8 oxidation state has been reported as well in the volatile tetroxide PuO4. Though it readily decomposes via a reduction mechanism similar to FeO4, it is stated that PuO4 can be stabilized in alkaline solutions, tetrachloromethane, and chloroform. However, a more recent study showed that Pu(VIII) does not form in aqueous alkaline solutions. Metallic plutonium is produced by reacting plutonium tetrafluoride with barium, calcium or lithium at 1200 °C. Metallic plutonium is attacked by acids, oxygen, and steam but not by alkalis and dissolves easily in concentrated hydrochloric, hydroiodic and perchloric acids. Molten metal must be kept in a vacuum or an inert atmosphere to avoid reaction with air. At 135 °C the metal will ignite in air and will explode if placed in carbon tetrachloride.

Plutonium is a reactive metal. In moist air or moist argon, the metal oxidizes rapidly, producing a mixture of oxides and hydrides. If the metal is exposed long enough to a limited amount of water vapor, a powdery surface coating of PuO2 is formed. Also formed is plutonium hydride but an excess of water vapor forms only PuO2. Plutonium shows enormous, and reversible, reaction rates with pure hydrogen, forming plutonium hydride. It also reacts readily with oxygen, forming PuO and PuO2 as well as intermediate oxides; plutonium oxide fills 40% more volume than plutonium metal. The metal reacts with the halogens, see below. The following oxyhalides are observed: PuOF, PuOCl, PuOBr, and PuOI. It will react with carbon to form PuC, nitrogen to form PuN, and silicon to form PuSi2. The organometallic chemistry of plutonium complexes is typical for organoactinide species; a characteristic example of an organoplutonium compound is plutonocene. Computational chemistry methods indicate an enhanced covalent character in the plutonium-ligand bonding. Powders of plutonium, its hydrides and certain oxides like Pu2O3 are pyrophoric, meaning they can ignite spontaneously at ambient temperature and are therefore handled in an inert, dry atmosphere of nitrogen or argon. Bulk plutonium ignites only when heated above 400 °C. Pu2O3 spontaneously heats up and transforms into PuO2, which is stable in dry air, but reacts with water vapor when heated. Crucibles used to contain plutonium need to be able to withstand its strongly reducing properties. Refractory metals such as tantalum and tungsten along with the more stable oxides, borides, carbides, nitrides and silicides can tolerate this. Melting in an electric arc furnace can be used to produce small ingots of the metal without the need for a crucible. Cerium is used as a chemical simulant of plutonium for development of containment, extraction, and other technologies.

Halides Plutonium reacts readily with halogens, forming halides of composition PuX3 (X=F, Cl, Br, I) or PuX4 (X=F). The higher plutonium fluorides PuF5 and PuF6 and the higher plutonium chloride PuCl4 are also known, though PuF5 and PuCl4 are only known in the gas phase. Several of these compounds form hydrates, with compositions PuF3·0.40H2O, PuF3·0.75H2O, PuF4·2.5H2O, PuCl3·3H2O, PuCl3·6H2O, and PuBr3·6H2O.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Plutonium compounds

Start with the simplest possible case. Write down what Plutonium compounds 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 Plutonium compounds 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 Plutonium compounds 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 Plutonium compounds

In research: Plutonium compounds 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 Plutonium compounds 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: Plutonium compounds is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chemical compounds by element, Plutonium, Plutonium compounds, so understanding it makes those chapters shorter.
In everyday life: Look for Plutonium compounds 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 Plutonium compounds in 20 minutes

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

Frequently asked questions

What is Plutonium compounds in simple terms?

Plutonium compounds are compounds containing the element plutonium (Pu). At room temperature, pure plutonium is silvery in color but gains a tarnish when oxidized.

Why does Plutonium compounds 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 Plutonium compounds?

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 Plutonium compounds.