chemistry

Lewisite 3

Lewisite 3 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 Lewisite 3 rather than just read about it. In short: Lewisite 3 (L-3) is an organoarsenic chemical weapon, similar to lewisite 1 and lewisite 2. First synthesized in 1904 by Julius Arthur Nieuwland, it is usually found as a mixture of 2-chlorovinylarsonous dichloride (lewisite 1) as well as bis(2-chloroethenyl) arsinous chloride (lewisite 2) and tris(2-chlorovinyl)arsine (lewisite 3).

Key takeaways

Lewisite 3 belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Lewisite 3 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Lewisite 3 from memory before moving on to harder problems.

Reference excerpt

Lewisite 3 (L-3) is an organoarsenic chemical weapon, similar to lewisite 1 and lewisite 2. First synthesized in 1904 by Julius Arthur Nieuwland, it is usually found as a mixture of 2-chlorovinylarsonous dichloride (lewisite 1) as well as bis(2-chloroethenyl) arsinous chloride (lewisite 2) and tris(2-chlorovinyl)arsine (lewisite 3). Pure lewisite 1 is an oily liquid with an odor distinct to geraniums. When pure, it is colourless, but impure mixtures can appear amber, brown, or black.

Synthesis Lewisite 3 is made as a byproduct along with lewisite 2 in the reaction that makes lewisite 1. Acetylene reacts with arsenic trichloride in hydrochloric acid solution, with mercuric chloride as a catalyst, to give lewisite in 80 to 85% yield.

AsCl3 + C2H2 → (ClCH=CH)AsCl2 Lewisite 3 is formed when there are three additions of acetylene to the arsenic center instead of one.

Exposure Adverse health effects caused by lewisite can vary and depend on the amount and duration of exposure. Lewisite immediately damages the skin, eyes, and respiratory tract and is a strong irritant and blistering agent. Due to its arsenic center, lewisite may also cause problems similar to arsenic poisonings like stomach ailments and low blood pressure.

Inhalation Inhalation, the most common route of exposure, causes a burning pain and irritation throughout the respiratory tract, nosebleed (epistaxis), laryngitis, sneezing, coughing, vomiting, difficult breathing (dyspnea). From one acute exposure, someone who has inhaled lewisite can develop chronic respiratory disease. In severe cases of exposure, can cause fatal pulmonary edema, pneumonitis, or respiratory failure.

Ingestion Ingestion results in severe pain, nausea, vomiting, and tissue damage. Those exposed to lewisite can develop refractory hypotension (low blood pressure) known as "Lewisite shock", as well as some features of arsenic toxicity. Lewisite causes physical damage to capillaries, which then become leaky, meaning that there is not enough blood volume to maintain blood pressure, a condition called hypovolemia. When the blood pressure is low, the kidneys may not receive enough oxygen and can be damaged.

Eye exposure The results of eye exposure can range from stinging, burning pain, and strong irritation to blistering and scarring of the cornea, along with blepharospasm, lacrimation, and edema of the eyelids and periorbital area. Eye exposure to lewisite can cause permanent visual impairment or blindness. The eyes can swell shut, which can keep the eyes safe from further exposure. The most severe consequences of eye exposure to lewisite are globe perforation and blindness. Generalised symptoms also include restlessness, weakness, hypothermia, and low blood pressure.

Chronic exposure Chronic exposure to lewisite can cause arsenic poisoning and development of a lewisite allergy. It can also cause various long-term illnesses or permanent damage to organs, depending on where the exposure has occurred, including conjunctivitis, aversion to light (photophobia), visual impairment, double vision (diplopia), tearing (lacrimation), dry mucous membranes, garlic breath, burning pain in the nose and mouth, toxic encephalopathy, peripheral neuropathy, seizures, nausea, vomiting, chronic obstructive pulmonary disease (COPD), bronchitis, dermatitis, skin ulcers, basal cell carcinoma, and squamous cell carcinoma.

Treatment Basic first aid for lewisite exposure is decontamination and irrigation of any areas that have been exposed, and when necessary airway management, assisted ventilation, and monitoring of vital signs. Dimercaprol, also called "British anti-lewisite", is the antidote for lewisite. It can be injected to prevent systemic toxicity, but will not prevent injury to the skin, eyes, or mucous membranes. Chemically, dimercaprol is a chelating agent that binds to the arsenic in lewisite. It is contraindicated in those with peanut allergies.

Illustrations

Worked examples

Example 1 — a first encounter with Lewisite 3

Start with the simplest possible case. Write down what Lewisite 3 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 Lewisite 3 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 Lewisite 3 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 Lewisite 3

In research: Lewisite 3 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 Lewisite 3 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: Lewisite 3 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Alkene derivatives, Arsenic(III) compounds, Arsenical vesicants, so understanding it makes those chapters shorter.
In everyday life: Look for Lewisite 3 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 Lewisite 3 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Lewisite 3 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 Lewisite 3 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Lewisite 3 in simple terms?

Why does Lewisite 3 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 Lewisite 3?

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 Lewisite 3.