chemistry

Nickel(II) chromate

Nickel(II) chromate 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 Nickel(II) chromate rather than just read about it. In short: Nickel(II) chromate is an inorganic compound with the chemical formula (NiCrO4). It is red-brown in color and has a high heat tolerance.

Key takeaways

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

Reference excerpt

Nickel(II) chromate is an inorganic compound with the chemical formula (NiCrO4). It is red-brown in color and has a high heat tolerance. It is very slightly soluble in water and soluble in acid. It and the ions that compose it (nickel(II) and chromate) have been linked to tumor formation and gene mutation, particularly to wildlife.

Synthesis Nickel(II) chromate can be formed in the lab by heating a mixture of chromium(III) oxide and nickel oxide at between 700 °C and 800 °C under oxygen at 1000 atm pressure. It can be produced at 535 °C and 7.3 bar oxygen, but the reaction takes days to complete. If the pressure is too low or temperature too high but above 660 °C, then the nickel chromium spinel NiCr2O4 forms instead. It is claimed it can be made using a hydrothermal technique. Precipitates of Ni2+ ions with chromate produce a brown substance that contains water.

Properties The structure of nickel chromate is the same as for chromium vanadate, CrVO4. Crystals have an orthorhombic structure with unit cell sizes a = 5.482 Å, b = 8.237 Å, c = 6.147 Å. The cell volume is 277.6 Å3 with four formula per unit cell. Nickel chromate is dark in color, unlike most other chromates which are yellow. The infrared spectrum of nickel chromate show two sets of absorption bands. The first includes lines at 925, 825, and 800 cm−1 due to Cr-O stretching, and the second has lines at 430, 395, 365 (very weak) due to Cr-O rock and bend and 310 cm−1 produced from Ni-O stretching.

Reactions When heated at lower oxygen pressure around 600 °C, nickel chromate decomposes to the nickel chromite spinel, nickel oxide and oxygen.

4 NiCrO4 → 2 NiCr2O4 + 2 NiO + 3 O2 (gas)

Related compounds Nickel chromates can also crystallize with ligands. For instance, with 1,10-phenanthroline it can form:

[Ni(1,10-phenanthroline)CrO4•3H2O]•H2O – triclinic olive-colored crystals Ni(1,10-phenanthroline)3Cr2O7•3H2O – orange crystals Ni(1,10-phenanthroline)3Cr2O7•8H2O – yellow powder

References

Illustrations

Worked examples

Example 1 — a first encounter with Nickel(II) chromate

Start with the simplest possible case. Write down what Nickel(II) chromate 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 Nickel(II) chromate 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 Nickel(II) chromate 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 Nickel(II) chromate

In research: Nickel(II) chromate 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 Nickel(II) chromate 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: Nickel(II) chromate is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chromates, Nickel compounds, Oxidizing agents, so understanding it makes those chapters shorter.
In everyday life: Look for Nickel(II) chromate 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Nickel(II) chromate” →

Affiliate

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

How to study Nickel(II) chromate in 20 minutes

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

Frequently asked questions

What is Nickel(II) chromate in simple terms?

Nickel(II) chromate is an inorganic compound with the chemical formula (NiCrO4). It is red-brown in color and has a high heat tolerance.

Why does Nickel(II) chromate 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 Nickel(II) chromate?

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 Nickel(II) chromate.