chemistry

Lanthanum hydroxide

Lanthanum hydroxide 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 Lanthanum hydroxide rather than just read about it. In short: Lanthanum hydroxide is La(OH)3, a hydroxide of the rare-earth element lanthanum. Synthesis Lanthanum hydroxide can be obtained by adding an alkali such as ammonia to aqueous solutions of lanthanum salts such as lanthanum nitrate.

Key takeaways

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

Reference excerpt

Lanthanum hydroxide is La(OH)3, a hydroxide of the rare-earth element lanthanum.

Synthesis Lanthanum hydroxide can be obtained by adding an alkali such as ammonia to aqueous solutions of lanthanum salts such as lanthanum nitrate. This produces a gel-like precipitate that can then be dried in air.

La(NO3)3 + 3 NH4OH → La(OH)3 + 3 NH4NO3 Alternatively, it can be produced by hydration reaction (addition of water) to lanthanum oxide.

La2O3 + 3 H2O → 2 La(OH)3

Characteristics Lanthanum hydroxide does not react much with alkaline substances, however is slightly soluble in acidic solution. In temperatures above 330 °C it decomposes into lanthanum oxide hydroxide (LaOOH), which upon further heating decomposes into lanthanum oxide (La2O3):

La(OH)3 → − H 2 O 330 o C {\displaystyle \mathrm {{\xrightarrow[{-H_{2}O}]{330\ ^{o}C}}\ } } LaOOH 2 LaOOH → − H 2 O Δ {\displaystyle \mathrm {{\xrightarrow[{-H_{2}O}]{\Delta }}\ } } La2O3 Lanthanum hydroxide crystallizes in the hexagonal crystal system. Each lanthanum ion in the crystal structure is surrounded by nine hydroxide ions in a tricapped trigonal prism.

References

External links "Lanthanum - Element information, properties and uses - Periodic Table". rsc.org. External MSDS 1 External MSDS 2 Lanthanum Oxide MSDS

Illustrations

Worked examples

Example 1 — a first encounter with Lanthanum hydroxide

Start with the simplest possible case. Write down what Lanthanum hydroxide 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 Lanthanum hydroxide 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 Lanthanum hydroxide 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 Lanthanum hydroxide

In research: Lanthanum hydroxide 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 Lanthanum hydroxide 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: Lanthanum hydroxide is common in secondary-school and first-year university syllabi. It links to neighbouring topics Hydroxides, Inorganic compound stubs, Inorganic compounds, so understanding it makes those chapters shorter.
In everyday life: Look for Lanthanum hydroxide 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 Lanthanum hydroxide in 20 minutes

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

Frequently asked questions

What is Lanthanum hydroxide in simple terms?

Lanthanum hydroxide is La(OH)3, a hydroxide of the rare-earth element lanthanum. Synthesis Lanthanum hydroxide can be obtained by adding an alkali such as ammonia to aqueous solutions of lanthanum salts such as lanthanum nitrate.

Why does Lanthanum hydroxide 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 Lanthanum hydroxide?

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 Lanthanum hydroxide.