chemistry

Potassium trichloridocuprate(II)

Potassium trichloridocuprate(II) 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 Potassium trichloridocuprate(II) rather than just read about it. In short: Potassium trichloridocuprate(II) is a salt with chemical formula KCuCl3, more properly [K+]2[Cu2Cl2−6]. It is a member of the "halide" sub-family of perovskite materials with general formula ABX3 where A is a monovalent cation, B is a divalent cation, and X is a halide anion.

Key takeaways

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Reference excerpt

Potassium trichloridocuprate(II) is a salt with chemical formula KCuCl3, more properly [K+]2[Cu2Cl2−6]. It is a member of the "halide" sub-family of perovskite materials with general formula ABX3 where A is a monovalent cation, B is a divalent cation, and X is a halide anion. The compound occurs in nature as the bright red mineral sanguite. The compound is also called potassium trichlorocuprate(II), potassium copper(II) trichloride, potassium cupric chloride and other similar names. The latter is used also for potassium tetrachloridocuprate(II) K2CuCl4.

Preparation and properties The compound can be obtained by evaporation of a solution of potassium chloride KCl and copper(II) chloride CuCl2 in 1:1 mole ratio. The anhydrous form is garnet-red. It can be crystallized from a molten mixture of potassium chloride KCl and copper(II) chloride CuCl2. or by evaporation from a solution of the salts in ethanol. It is very hygroscopic, and soluble in methanol and ethanol. It is antiferromagnetic below 30 K, and pleochroic, with maximum visible absorption when the electric vector is parallel to the Cu–Cu vector of the dimer.

Structure

Anhydrous The anhydrous mineral form (sanguite) has the monoclinic crystal structure, with symmetry group P21/c and lattice parameters a = 402.81 pm, b = 1379.06 pm, c = 873.35 pm, and β = 97.137°, cell volume V = 0.48138 nm3, and formulas per cell Z = 4. The measured density is 2.86 g/cm3, close to the calculated one 2.88 g/cm3. It contains discrete almost planar anions [Cu2Cl6]2−, each with the two copper atoms connected by two bridging chlorine atoms. These anions are arranged in columns consisting of distorted edge-sharing CuCl6 octahedra, stacked in double chains parallel to the a axis. The columns occupy the edges and the centre of the cell's projection on the bc plane. The potassium atoms are located between these columns; each K+ cation is surrounded by nine chlorine atoms. The mineral is optically biaxial (negative), with α = 1.653, β = 1.780, γ = 1.900', 2V= 85°. The mineral is named from the Latin sanguis (blood), alluding to its color. Theoretical calculations for this topology give the lattice parameters as a = 1388.1 pm, b = 427.7 pm, c = 896.5 pm, α = 79.855°, cell volume V = 0.523891 nm3, calculated density 2.65 g/cm3.

Theoretical An alternative theoretical structure for the compound has a cubic crystal system, symmetry group Pm3m[221], with the copper atoms arranged as corners of a cubic grid, a potassium atom at the center of each cube and a chlorine atom at the midpoint of each edge. The latice parameters are a = b = c = 485.8 pm, V = 0.114684 nm3, predicted density 3.03 g/cm3.

References

Worked examples

Example 1 — a first encounter with Potassium trichloridocuprate(II)

Start with the simplest possible case. Write down what Potassium trichloridocuprate(II) 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 Potassium trichloridocuprate(II) 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 Potassium trichloridocuprate(II) 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 Potassium trichloridocuprate(II)

In research: Potassium trichloridocuprate(II) 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 Potassium trichloridocuprate(II) 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: Potassium trichloridocuprate(II) is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chloro complexes, Copper(II) compounds, Potassium compounds, so understanding it makes those chapters shorter.
In everyday life: Look for Potassium trichloridocuprate(II) 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 Potassium trichloridocuprate(II) in 20 minutes

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Frequently asked questions

What is Potassium trichloridocuprate(II) in simple terms?

Why does Potassium trichloridocuprate(II) 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 Potassium trichloridocuprate(II)?

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 Potassium trichloridocuprate(II).