Oxyacids & Their Derivatives – Lecture Review

Fill-in-the-blank flashcards covering definitions, formulas and key properties of oxyacids of P, S, N, Cl, B and related concepts presented in the lecture.

A “pyro” acid is produced by condensing two moles of an oxy-acid and is characterized by the _ linkage.

X–O–X (e.g., P–O–P)

The molecular formula of pyro-sulphuric acid (oleum) is _.

H₂S₂O₇

Removing one H₂O molecule from a single oxy-acid molecule gives a _ acid.

meta

Meta-phosphoric acid has the formula _.

HPO₃

Meta-boric acid is represented by the formula _.

HBO₂

Lower-oxidation-state acids obtained by loss of oxygen are called _ acids.

hypo

Hypo-phosphorous acid, noted for its reducing P–H bonds, has the formula _.

H₃PO₂

Adding an extra oxygen to an oxy-acid (with an –O–O– bond) produces a _ acid.

peroxy (or per)

The characteristic –O–O– linkage found in per-acids is called a _ linkage.

peroxy

Nitrogen in its oxy-acids is generally _ hybridized.

sp²

The formula for nitrous acid is _.

HNO₂

The formula for nitric acid is _.

HNO₃

Per-nitric (peroxynitric) acid is written as _.

HNO₄

The sequence of chlorine oxy-acids begins with hypochlorous acid whose formula is _.

HOCl (or HClO)

Perchloric acid, the highest oxy-acid of chlorine, has the formula _.

HClO₄

Oxy-acids HOBr and HOI exist only in _, not as isolated solids.

solution

Hypo-phosphorous acid is _-basic because it contains only one replaceable hydrogen.

mono (or 1)

Phosphorous (phosphonic) acid, H₃PO₃, is _-basic.

di (2)

Orthophosphoric acid, H₃PO₄, is _-basic.

tri (3)

Pyro-phosphoric acid (H₄P₂O₇) has a basicity of _.

four (tetra)

Metaphosphoric acid (HPO₃) rarely exists as monomer; it polymerises to cyclic or linear units described as _ metaphosphate.

poly (e.g., (HPO₃)ₙ)

Sodium hexametaphosphate (commercially called _) is used to soften hard water.

Calgon

In polyphosphoric acids, the number of P–O–P linkages equals (n − 1), where n is the number of _ atoms.

phosphorus

Heating 2 H₃PO₄ removes one H₂O and yields the compound _.

H₄P₂O₇ (pyro-phosphoric acid)

Caro’s acid, a peroxomonosulphuric acid, has the formula _.

H₂SO₅

Marshall’s acid, a peroxodisulphuric acid, is written as _.

H₂S₂O₈

The salt K₂S₂O₈ is commonly known as _.

potassium per-sulphate (or potassium peroxodisulfate)

Sulphuric acid (H₂SO₄) is _-basic.

di

Removing one H₂O from two H₂SO₄ molecules forms _ acid.

pyro-sulphuric (H₂S₂O₇)

Thiosulphuric acid differs from sulphuric acid by replacing one oxygen with _.

sulphur

Meta-boric acid on further heating ultimately yields the oxide _.

B₂O₃

Concentrated H₂SO₄ acts as a dehydrating agent, turning sucrose black in the classic _ of sugar.

charring

Formic acid plus conc. H₂SO₄ decomposes to give _ gas and water.

carbon monoxide (CO)

Oxalic acid heated with conc. H₂SO₄ produces CO, _, and H₂O.

CO₂

Malonic acid with conc. H₂SO₄ yields the rare carbon suboxide, formula _.

C₃O₂

Oxy-acids of P containing P–H bonds (e.g., H₃PO₂) can undergo disproportionation to give PH₃ and a higher-oxidation acid.

phosphoric

In naming salts, an “-ate” anion comes from an “-ic” acid, whereas an “-ite” anion comes from an “-” acid.

ous

An oxy-acid’s basicity equals the number of _ hydrogens it can donate.

replaceable (or acidic)