Question

Which of the following acids is capable of dissolving gold?
A.Hydrochloric acid
B.Nitric acid
C.Sulfuric acid
D.A combination of A and B.
E.A combination of A and C.

Answer 1

Hint:Gold is promptly solvent in water regia, or in some other combination delivering early chlorine, among such blends being arrangements of nitrates, chlorides, and corrosive sulfates. Generally any chloride, bromide, or iodide will break down gold in presence of an oxidizing specialist. The activity is substantially more fast if heat is applied, or if the gold is alloyed with one of the base metals.

Complete answer:
Aqua regia is a combination of nitric acid and hydrochloric acid, ideally in a molar proportion of 1:3. Aqua regia is a yellow-orange (once in a while red) raging fluid, so named by chemists since it can break down the respectable metals, gold and platinum, however not all metals. After mixing of concentrated hydrochloric acid and concentrated nitric acid, substance responses happen. These responses bring about the unstable items’ nitrosyl chloride and chlorine gas:
$HN{O}_{3(aq)}+3HC{l}_{(aq)}\to NOC{l}_{(g)}+C{l}_{(g)}+2H_2{O}_{(l)}$
A combination of hydrochloric acid and nitric acid in the proportion 3:1. It is a solid acid and can break down any metals including honorable metals like gold and silver.

Thus , based on the above explanation the correct answer to the question is, option D.

Note:
Nitric acid is an incredible oxidizer, which will really disintegrate a basically imperceptible measure of gold, framing gold particles $(A{u}^{3+})$ . The hydrochloric acid gives a prepared supply of chloride particles $(C{l}^{-})$, which respond with the gold particles to deliver tetrachloroaurate (III) anions, likewise in arrangement. The response with hydrochloric acid is an equilibrium response that favors formation of chloroaurate anions $(AuC{l_4}^{-})$. This outcomes in removal of gold particles from solution and permits further oxidation of gold to happen. The gold disintegrates to become chloroauric acid. Moreover, gold might be broken down by the chlorine present in water regia.