chemistry

Lead(IV) chloride

Lead(IV) chloride 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 Lead(IV) chloride rather than just read about it. In short: Lead tetrachloride, also known as lead(IV) chloride, has the molecular formula PbCl4. It is a yellow, oily liquid which is stable below 0 °C, and decomposes at 50 °C.

Key takeaways

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

Reference excerpt

Lead tetrachloride, also known as lead(IV) chloride, has the molecular formula PbCl4. It is a yellow, oily liquid which is stable below 0 °C, and decomposes at 50 °C. It has a tetrahedral configuration, with lead as the central atom. The Pb–Cl covalent bonds have been measured to be 247 pm and the bond energy is 243 kJ⋅mol−1.

Synthesis Lead tetrachloride can be made by reacting lead(II) chloride PbCl2, and hydrochloric acid HCl, in the presence of chlorine gas (Cl2), leading to the formation of chloroplumbic acid H2PbCl6. It is then converted to the ammonium salt (NH4)2PbCl6 by adding ammonium chloride (NH4Cl). Finally, the solution is treated with concentrated sulfuric acid H2SO4, to separate out lead tetrachloride. This series of reactions is conducted at 0 °C. The following equations illustrate the reaction:

PbCl2 + 2HCl + Cl2 → H2PbCl6 H2PbCl6 + 2 NH4Cl → (NH4)2PbCl6 + 2HCl (NH4)2PbCl6 + H2SO4 → PbCl4+ 2HCl + (NH4)2SO4

Reaction with water Unlike carbon tetrachloride, another group IV (IUPAC: group 14) chloride, lead tetrachloride reacts with water. This is because Pb has a larger atomic radius than C, so there is less steric hindrance around that central atom and water can more easily access it. Also, because of the presence of empty d atomic orbitals on the Pb atom, oxygen can bind to it before a Pb–Cl bond has to break, thus requiring less activation energy. The overall reaction is thus as follows:

PbCl4 + 2H2O → PbO2(s) + 4HCl(g)

Stability Lead tetrachloride tends to decompose further into lead dichloride and chlorine gas:

PbCl4 → PbCl2 + Cl2(g) There are reports that this reaction can proceed explosively and that the compound is best stored under pure sulfuric acid at –80 °C in the dark. The stability of the +4 oxidation state decreases going down group 14 of the periodic table. Thus, while carbon tetrachloride is a stable compound, with lead the oxidation state +2 is favored and PbCl4 quickly becomes PbCl2. Indeed, the inert pair effect causes lead to favor its +2 oxidation state: Pb atom loses all its outermost p electrons and ends up with a stable, filled s subshell.

Toxicity Lead is a cumulative poison. Only limited evidence have been shown of lead's carcinogenic effect, but lead tetrachloride, as well as all other lead compounds, is "reasonably anticipated to be human carcinogens" according to the Report on Carcinogens, Twelfth Edition (2011). Lead can be absorbed by the body through several routes, primarily inhalation but also ingestion and dermal contact. Lead compounds are also teratogens.

References

Illustrations

Worked examples

Example 1 — a first encounter with Lead(IV) chloride

Start with the simplest possible case. Write down what Lead(IV) chloride 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 Lead(IV) chloride 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 Lead(IV) chloride 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 Lead(IV) chloride

In research: Lead(IV) chloride 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 Lead(IV) chloride 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: Lead(IV) chloride is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chlorides, Lead(IV) compounds, Metal halides, so understanding it makes those chapters shorter.
In everyday life: Look for Lead(IV) chloride 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.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Lead(IV) chloride in 20 minutes

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

Frequently asked questions

What is Lead(IV) chloride in simple terms?

Lead tetrachloride, also known as lead(IV) chloride, has the molecular formula PbCl4. It is a yellow, oily liquid which is stable below 0 °C, and decomposes at 50 °C.

Why does Lead(IV) chloride 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 Lead(IV) chloride?

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 Lead(IV) chloride.