What is aqua regia Why are gold and platinum soluble in it?

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What is aqua regia Why are gold and platinum soluble in it?

Aqua regia, as we know, consists of nitric acid, i.e., HNO3 which acts as a strong oxidizing agent. This nitric acid converts the gold or platinum metal to their corresponding ions by oxidizing them. This tetrachloroaurate present in aqua regia then quickly dissolves to form chloroauric acid, i.e., HAuCl4.

What happens when gold reacts with aqua regia?

The equilibrium reaction takes place between HCl and gold which leads to the production of chloroaurate anions in the solution. The formation of chloroauric acid takes place once the gold gets completely soluble in aqua regia due to the presence of free chlorine.

Why aqua regia dissolves gold which is insoluble in all other acids?

In aqua regia HCl is a very strong acid and free chlorine is a very strong oxidising agent as it is present in high concentration. Nitric acid reacts with HCl to form nitrosyl chloride NOCl,chlorine and water. Chlorine dissolves gold oxidizing this metal Au to Au(III)ions forming soluble tetrachloroaurate(III)complex.

When gold dissolves in aqua regia What is reduced?

Identifying oxidation numbers allows the identification of elements that are reduced and oxidized. Nitrogen goes from a +5 to a +4 state and is reduced; gold goes from a 0 to +3 state and is oxidized. With gold oxidized, Cl- ions in solution from hydrochloric acid combine with Au3+ to form AuCl4-, the chloroaurate ion.

What is aqua regia and how does it dissolve gold?

aqua regia, mixture of concentrated nitric and hydrochloric acids, usually one part of the former to three parts of the latter by volume. This mixture was given its name (literally, “royal water”) by the alchemists because of its ability to dissolve gold. It is a red or yellowish liquid.

Which of the following sulphides is soluble in aqua regia?

Aqua regia is a yellow-orange (sometimes red) fuming liquid, so named by alchemists because it can dissolve the noble metals gold and platinum, though not all metals….Aqua regia.

Names
Solubility in water Miscible
Vapor pressure 21 mbar
Hazards
NFPA 704 (fire diamond) 3 0 0 OX

Which sulphides are soluble only in aqua regia?

When gold dissolves in aqua regia products formed are?

chloroauric acid
When gold dissolves in aqua regia, chloroauric acid is formed.

When gold dissolves in aqua regia the products formed are?

Once the above reaction with $HCl$ reaches equilibrium it leads to the formation of chloroaurate anions(${left[ {AuC{l_4}} right]^ – }$) and the gold ions are removed from the solution making way for oxidation to occur. Hence the product is $HAuC{l_4}$ .

Which is soluble only in aqua regia?

Aqua regia is a yellow-orange (sometimes red) fuming liquid, so named by alchemists because it can dissolve the noble metals gold and platinum, though not all metals….Aqua regia.

Names
Melting point −42 °C (−44 °F; 231 K)
Boiling point 108 °C (226 °F; 381 K)
Solubility in water Miscible
Vapor pressure 21 mbar

Is ZnS soluble in aqua regia?

Zinc Sulfide ZnS 2.19 355 10,000 22,000-750 (0.45-14.0) 14,000-1000 (0.7-10) Soluble in acid; insoluble in water. Germanium Ge 4.0 550 7000 5000-600 (2.0-17) 5000-900 (2.0-1.4) Insoluble in water; soluble in hot H2SO4 and aqua regia.

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