chemistry

Stearolic acid

Stearolic acid 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 Stearolic acid rather than just read about it. In short: Stearolic acid is an acetylenic fatty acid characterized by an 18-carbon chain with a triple bond between carbons 9 and 10. It is a rare, naturally occurring unsaturated fatty acid, notable for its unique chemical structure and occurrence in certain plant species.

Key takeaways

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

Reference excerpt

Stearolic acid is an acetylenic fatty acid characterized by an 18-carbon chain with a triple bond between carbons 9 and 10. It is a rare, naturally occurring unsaturated fatty acid, notable for its unique chemical structure and occurrence in certain plant species. Its structural formula is CH3(CH2)7C≡C(CH2)7COOH. Its delta notation is 18:1Δ9a. Stearolic acid is classified as an octadecynoic acid, specifically with the triple bond at the 9-position, hence its common name, 9-octadecynoic acid.

Natural occurrence Stearolic acid has been reported to occur in lipids of plant origin, in particular in the seed oil of Pyrularia edulis, Pyrularia pubera, Santalum album, Santalum acuminatum, Acanthosyris spinescens, and Exocarpus cupressiformis. Oils with a high stearolic acid content are drying oils that polymerize in relatively short times. Its presence in these plants is relatively rare compared to more common fatty acids, such as stearic and oleic acids. Stearolic acid is considered to be the main precursor of other acetylenic fatty acids, in particular ximenynic acid and exocarpic acid, with which it is frequently identified.

Synthesis Stearolic acid can be synthesized from oleic acid through a process involving halogenation of the alkene followed by double dehydrohalogenation to form a triple bond. The net effect is conversion of the double bond to a triple bond at the same location on the fatty acid chain.

Physical properties The acid is practically insoluble in water, but readily soluble in diethyl ether and hot ethanol. Stearolic acid crystallizes in the monoclinic crystal system in the space group C 2h with the lattice parameters a = 9.551 Å; b = 4.686 Å, c = 49.15 Å and β = 53.4° and four formula units per unit cell.

Chemical properties Ozonolysis of stearolic acid yields 9,10-dioxostearic acid, having two ketone groups at the site where the alkyne was. This compound can also be formed by reacting stearolic acid with potassium permanganate, although depending on the pH during the reaction, cleavage of the carbon chain can also occur. When reacted with molten potassium hydroxide, stearolic acid decomposes into myristic acid and acetic acid.

Biological and chemical significance Acetylenic fatty acids like stearolic acid are of interest for their unique chemical reactivity and potential biological activities. However, detailed studies on the biological roles and applications of stearolic acid are limited compared to more common fatty acids.

References

Worked examples

Example 1 — a first encounter with Stearolic acid

Start with the simplest possible case. Write down what Stearolic acid 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 Stearolic acid 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 Stearolic acid 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 Stearolic acid

In research: Stearolic acid 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 Stearolic acid 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: Stearolic acid is common in secondary-school and first-year university syllabi. It links to neighbouring topics Alkynoic acids, Fatty acids, so understanding it makes those chapters shorter.
In everyday life: Look for Stearolic acid 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 Stearolic acid in 20 minutes

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

Frequently asked questions

What is Stearolic acid in simple terms?

Why does Stearolic acid 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 Stearolic acid?

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 Stearolic acid.