Why nitric acid do not react with gold and platinum?

Gold and platinum are inert metals. They comes below the hydrogen gas in electrochemical series, so these are very less reactive metals and can not replace hydrogen. So gold and platinum can not react with nitric acid.

Why does hno3 not react with noble metals?

The metals that come below hydrogen in the electrochemical series usually are very less reactive metals. That is why they cannot replace hydrogen and hence do not usually react with nitric acid, while the ones above hydrogen react with nitric acid very efficiently.

Which metal does not get affected by nitric acid?

Some precious metals, such as pure gold and platinum-group metals do not react with nitric acid, though pure gold does react with aqua regia, a mixture of concentrated nitric acid and hydrochloric acid.

Why are noble metals less reactive?

Noble metals already have there outermost electron shells completely filled. So they do not need to partake in reactions. Hence they’re their unreactivity.

How does gold react to nitric acid?

The two acidic testing solutions react with gold alloys by dissolving all or some of the metals within them. Nitric acid dissolves copper and silver by oxidizing them, as described by the chemical equations below. The more copper or silver within the gold alloy, the faster the alloy will dissolve.

What happens when gold is treated with a mixture of conc HNO3 and conc HCl?

Nitric acid will act as the oxidizer and is used to form gold ions (Au3+). The hydrochloric acid is then used to react with the gold ions to form tetrachloroaurate(III) anions. The gold ions can then be removed from the solution which further allows the oxidation of gold.

Why does gold not dissolve in nitric acid?

Aqua Regia is a mixture of two acids, hydrochloric acid and nitric acid. Nitric acid doesn’t really react with gold very much at all, and HCl, hydrogen chloric acid can’t get a hold of the gold to get the reaction going.

Why does gold not react with dilute acids?

When a metal piece is added to dilute acid, the metal forms its corresponding cation which reacts with the anion of the acid and forms a salt and hydrogen gas is evolved. We know gold is a noble metal and it lies below hydrogen in the reactivity series and thus it is unreactive towards acids.

Which of the following does not react with concentrated hno3?

Zinc. Chromium do not dissolve in concentrated nitric acid because of the formation of a passive film of oxide on the surface.

Why gold and platinum are called noble metals?

Noble elements are those elements which are resistant with corrosion and oxidation of air. Gold and platinum don’t take part in any chemical reaction. They are not affected by heat, air, water, acid and base. That’s why gold and platinum are called noble elements.

Why are platinum metals called noble metals?

Answer: Platinum and gold are called noble metals because of stability and do not react with other metals. Both resist oxidation and corrosion. Gold and Platinum jewelry always remains on high demand.

Does gold dissolve in concentrated nitric acid?

Lower karat gold alloys will dissolve more quickly than higher karat alloys because they contain more copper or silver, which dissolve in nitric acid, while gold does not.

What is the name of the compound HNO3?

Nitric acid is a nitrogen oxoacid of formula HNO3 in which the nitrogen atom is bonded to a hydroxy group and by equivalent bonds to the remaining two oxygen atoms. It has a role as a protic solvent and a reagent. It is a conjugate acid of a nitrate. Nitric acid (HNO3).

What is the percentage concentration of HNO3 in nitric acid?

The ACS defines two grades of reagent acid: nitric acid, having a concentration of 69.0-71.0 wt\% HNO3, and nitric acid, 90\%, having a concentration of 90 wt\% HNO3.

What is the difference between fuming nitric acid and fuming HNO3?

When the solution contains more than 86\% HNO3, it is referred to as fuming nitric acid. Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as white fuming nitric acid at concentrations above 95\%, or red fuming nitric acid at concentrations above 86\%.

Which of the following metals can dissolve in nitric acid?

Although chromium (Cr), iron (Fe), and aluminium (Al) readily dissolve in dilute nitric acid, the concentrated acid forms a metal-oxide layer that protects the bulk of the metal from further oxidation.