Naphtha

Key takeaways

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

Reference excerpt

Naphtha (, more rarely: ) is a flammable liquid hydrocarbon mixture. Generally, it is a fraction of crude oil, but it can also be produced from natural-gas condensates, petroleum distillates, and the fractional distillation of coal tar and peat. In some industries and regions, the name naphtha refers to crude oil or refined petroleum products such as kerosene or diesel fuel. It is used as a dilutant, a fuel and in the production of plastics. Naphtha is also known as Shellite in Australia.

Etymology

The word naphtha comes from Latin through Ancient Greek (νάφθα), derived from Middle Persian naft ("wet", "naphtha"), the latter meaning of which was an assimilation from the Akkadian 𒉌𒆳𒊏 napṭu (see Semitic relatives such as Arabic نَفْط nafṭ ["petroleum"], Syriac ܢܰܦܬܳܐ naftā, and Hebrew נֵפְט neft, meaning petroleum).

Antiquity The Treaty of Esarhaddon (c. 675 BC) briefly mentions during a listing of curses how "naphtha [shall] be your ointment" if the oath made in the treaty is broken. Further on, it also prescribes the curse:

May they make your flesh and the flesh of your women, your brothers, your sons and your daughters as black as [bitu]men, pitch and naphtha. The book of II Maccabees (2nd cent. BC) tells how a "thick water" was put on a sacrifice at the time of Nehemiah and when the sun shone it caught fire. It adds that "those around Nehemiah termed this 'Nephthar,' which means Purification, but it is called Nephthaei by the many." This same substance is mentioned in the Mishnah as one of the generally permitted oils for lamps on Shabbat, although Rabbi Tarfon permits only olive oil (Mishnah Shabbat 2). In Ancient Greek, it was used to refer to any sort of petroleum or pitch. The Greek word νάφθα designates one of the materials used to stoke the fiery furnace in the Song of the Three Children (possibly 1st or 2nd cent. BC). The translation of Charles Brenton renders this as "rosin." The naphtha of antiquity is explained to be a "highly flammable light fraction of petroleum, an extremely volatile, strong-smelling, gaseous liquid, common in oil deposits of the Near East;" it was a chief ingredient in incendiary devices described by Latin authors of the Roman period.

Modern period Since the 19th century, solvent naphtha has denoted a product (xylene or trimethylbenzenes) derived by fractional distillation from petroleum; these mineral spirits, also known as "Stoddard Solvent," were originally the main active ingredient in Fels Naptha laundry soap. The naphtha in Fels Naptha was later removed as a cancer risk. The usage of the term "naphtha" during this time typically implies petroleum naphtha, a colorless liquid with a similar odor to gasoline. However, "coal tar naphtha," a reddish brown liquid that is a mixture of hydrocarbons (toluene, xylene, and cumene, etc.), could also be intended in some contexts.

Petroleum Generally, in pre 19th century sources, "naphtha" simply meant crude oil, but this usage is now obsolete in English. There are a number of cognates to the word in different modern languages, typically signifying "petroleum" or "crude oil." The Ukrainian & Belarusian word нафта (nafta), Lithuanian, Latvian, & Estonian "nafta," and the Persian naft (نفت) mean "crude oil." The Russian word нефть (neft') means "crude oil," but нафта (nafta) is a synonym of ligroin. Also, in Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Finland, Italy, Serbia, Slovenia, and North Macedonia nafta (нафта in Cyrillic) is colloquially used to indicate diesel fuel and crude oil. In the Czech Republic and Slovakia, nafta was historically used for both diesel fuel and crude oil, but its use for crude oil is now obsolete and it generally indicates diesel fuel. In Bulgarian, nafta means diesel fuel, while neft, as well as petrol (петрол in Cyrillic), means crude oil. Nafta is also used in everyday parlance in Argentina, Uruguay and Paraguay to refer to gasoline/petrol. Similarly, in Flemish, the word naft(e) is used colloquially for gasoline. In Poland, the word nafta means kerosene, and colloquially crude oil (the technical name for crude oil is ropa naftowa, also colloquially used for diesel fuel as ropa).

Types Naphtha has been divided into two types by many sources in order to differentiate between common grades more clearly: One source distinguishes by boiling point as well as carbon atom count per molecule:

Chemistry of Hazardous Materials differentiates light and heavy based on the carbon atom count and hydrocarbon structure:

Some sources also define petroleum naphtha, which contains both heavy and light naphtha, and typically consists of 15-30% of crude oil by weight.

Uses

Heavy crude oil dilution Naphtha is used to dilute heavy crude oil to reduce its viscosity and enable/facilitate transport; undiluted heavy crude cannot normally be transported by pipeline, and may also be difficult to pump onto oil tankers. Other common dilutants include natural-gas condensate and light crude. However, naphtha is a particularly efficient dilutant and can be recycled from diluted heavy crude after transport and processing. The importance of oil dilutants has increased as global production of lighter crude oils has fallen and shifted to exploitation of heavier reserves.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Naphtha

Start with the simplest possible case. Write down what Naphtha 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 Naphtha 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 Naphtha 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 Naphtha

In research: Naphtha 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 Naphtha 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: Naphtha is common in secondary-school and first-year university syllabi. It links to neighbouring topics Commodity chemicals, Hydrocarbon solvents, Petroleum products, so understanding it makes those chapters shorter.
In everyday life: Look for Naphtha 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.

How to study Naphtha in 20 minutes

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

Frequently asked questions

What is Naphtha in simple terms?

Naphtha (, more rarely: ) is a flammable liquid hydrocarbon mixture. Generally, it is a fraction of crude oil, but it can also be produced from natural-gas condensates, petroleum distillates, and the fractional distillation of coal tar and peat.

Why does Naphtha 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 Naphtha?

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 Naphtha.