science

Tetrahydroxyborate

Tetrahydroxyborate is a science 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 Tetrahydroxyborate rather than just read about it. In short: Tetrahydroxyborate is an inorganic anion with the chemical formula [BH4O4]− or [B(OH)4]−. It contributes no colour to tetrahydroxyborate salts.

Key takeaways

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

Reference excerpt

Tetrahydroxyborate is an inorganic anion with the chemical formula [BH4O4]− or [B(OH)4]−. It contributes no colour to tetrahydroxyborate salts. It is found in the mineral hexahydroborite, Ca(B(OH)4)2 · 2 H2O, originally formulated CaB2O4 · 6 H2O. It is one of the boron oxoanions, and acts as a weak base. The systematic names are tetrahydroxyboranuide (substitutive) and tetrahydroxidoborate(1−) (additive). It can be viewed as the conjugate base of boric acid.

Structure Tetrahydroxyborate has a symmetric tetrahedral geometry, isoelectronic with the hypothetical compound orthocarbonic acid (C(OH)4).

Chemical properties

Basicity Tetrahydroxyborate acts as a weak Brønsted–Lowry base because it can assimilate a proton (H+), yielding boric acid with release of water:

B(OH)−4 + H+ ⇌ B(OH)3 + H2O It can also release a hydroxide anion HO−, thus acting as a classical Arrhenius base:

B(OH)−4 ⇌ B(OH)3 + OH− (pK = 9.14 to the left) Thus, when boric acid is dissolved in pure (neutral) water, most of it will exist as tetrahydroxyborate ions.

With diols In aqueous solution, the tetrahydroxyborate anion reacts with cis-vicinal diols (organic compounds containing similarly-oriented hydroxyl groups in adjacent carbon atoms), (R1,R2)=C(OH)−C(OH)=(R3,R4)) such as mannitol, sorbitol, glucose and glycerol, to form anion esters containing one or two five-member −B−O−C−C−O− rings. For example, the reaction with mannitol can be written as

[B(OH)4]− + H(HCOH)6H ⇌ [B(OH)2(H(HCOH)2(HCO−)2(HCOH) )]− + 2 H2O [B(OH)2(H(HCOH)2(HCO−)2(HCOH)2H)]− + H(HCOH)6H ⇌ [B(H(HCOH)2(HCO−)2(HCOH)2H)2]− + 2 H2O Giving the overall reaction

[B(OH)4]− + 2 H(HCOH)6H ⇌ [B(H(HCOH)2(HCO−)2(HCOH)2H)2]− + 4 H2O These mannitoborate esters are fairly stable and thus depletes the tetrahydroxyborate from the solution. The addition of mannitol to an initially neutral solution containing boric acid or borates lowers the pH enough for the be titrated by a strong base as NaOH, including with an automated a potentiometric titrator. This is a reliable method to assay the amount of borate content present in the solution.

Other chemical reactions Upon treatment with a strong acid, a metal tetrahydroxyborate converts to boric acid and the metal salt. Oxidation of tetrahydroxyborate gives the perborate anion [B2O4(OH)4]2−:

2 [B(OH)4]− + 2 O → [B2O4(OH)4]2− + 2 H2O When heated to a high temperature, tetrahydroxyborate salts decompose to produce metaborate salts and water, or to produce boric acid and a metal hydroxide:

n [B(OH)4]− → (([BO2]−)n) + 2n H2O [B(OH)4]− → B(OH)3 + HO−

Production Tetrahydroxyborate salts are produced by treating boric acid with an alkali such as sodium hydroxide, with catalytic amounts of water. Other borate salts may be obtained by altering the process conditions.

Uses Tetrahydroxyborate can be used as a cross-link in polymers.

Occurrence The tetrahydroxyborate anion is found in Na[B(OH)4], Na2[B(OH)4]Cl and CuII[B(OH)4]Cl.

Illustrations

Worked examples

Example 1 — a first encounter with Tetrahydroxyborate

Start with the simplest possible case. Write down what Tetrahydroxyborate claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 Tetrahydroxyborate 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 Tetrahydroxyborate 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 Tetrahydroxyborate

In research: Tetrahydroxyborate appears in science 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 Tetrahydroxyborate 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: Tetrahydroxyborate is common in secondary-school and first-year university syllabi. It links to neighbouring topics Anions, Borates, so understanding it makes those chapters shorter.
In everyday life: Look for Tetrahydroxyborate 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 Tetrahydroxyborate in 20 minutes

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

Frequently asked questions

What is Tetrahydroxyborate in simple terms?

Tetrahydroxyborate is an inorganic anion with the chemical formula [BH4O4]− or [B(OH)4]−. It contributes no colour to tetrahydroxyborate salts.

Why does Tetrahydroxyborate matter?

Because it connects several science 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 Tetrahydroxyborate?

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 Tetrahydroxyborate.