Question

The tarnishing of silver ornaments in atmosphere is due to formation of :
A.\[A{g_2}O,A{g_2}S\]
B.$AgN{O_3},A{g_2}S$
C.$AgOH,A{g_2}C{O_3}$
D.\[Ag\]

Answer 1

Hint: To answer this question, recall the concept of tarnishing.
The tarnishing of silver ornaments in the air is due to the reaction of silver with oxygen and hydrogen sulphide.

Complete step by step answer:
Tarnish is a type of chemical reaction formed as a product when a metal and a nonmetal compound, especially oxygen and sulfur dioxide react and undergo oxidation. The reaction for tarnishing can be represented as:
\[8Ag + 4{H_2}S \to {\text{ }}4A{g_2}S{\text{ }} + {\text{ 4}}{H_2}\; + {\text{ }}4{e^ - }\]
\[4Ag + {O_2}\;\; \to 2A{g_2}O + 4{e^ - }\]
Silver tarnish can be considered as a type of corrosion, but unlike rust, the underlying metal remains undamaged. The process of tarnishing is fastened through tap water contact as it has the presence of chlorine), various food items, perfume and hair spray etc. For slowing down the process of tarnishing, silver ornaments should be cleaned regularly
\[Ag + air({O_2} + {H_2}S) \to A{g_2}O + A{g_2}S\].

Hence, we can conclude that the correct option is option A.

Note:
Prevention of tarnish can be achieved by the use of barriers such as lacquers to prevent the reactive chemical species contacting the silver. Silver objects are routinely coated with a cellulose nitrate-based lacquer after cleaning. In the coating here is the addition of corrosion inhibitors.