Silver Reaction Causes Black Tarnish
Silver objects often turn black due to a chemical process called tarnishing. This occurs when the metal undergoes a chemical reaction with specific substances present in its environment.
Identifying the Substance Causing Blackening
The primary cause of silver tarnishing is its reaction with sulphur or sulphur-containing compounds. Hydrogen sulfide ($H_2S$), a gas commonly found in the atmosphere, is a frequent culprit.
The Chemical Reaction
When silver ($Ag$) comes into contact with sulphur ($S$), they react to form silver sulfide ($Ag_2S$). This compound is insoluble in water and possesses a distinct black color.
The chemical equation for this reaction can be represented as:
$2Ag(s) + S(s) \rightarrow Ag_2S(s)$
In the presence of hydrogen sulfide and oxygen, the reaction is more complex but still results in the formation of black silver sulfide.
Analysis of Options
- Magnesium (Mg), Zinc (Zn), and Carbon (C) do not directly cause silver to form a black tarnish through common reactions.
- Sulphur is the element that chemically reacts with silver to produce the black coating.
Therefore, sulphur is the substance with which silver reacts to turn black.
Similar Questions
- What is oxidization?
- Which of the following determines that a chemical reaction has not taken place?
- Which chemical process results in the formation of plaque on copper, the rusting of iron and the blackening of silver?
When electricity is passed through an aqueous solution of sodium chloride (called brine), it decomposes to form sodium hydroxide. This process is called:
When Barium Chloride (BaCl2) solution is mixed with Sodium Sulfate (Na2SO4) solution, a white product Barium Sulfate (BaSO4) is formed. This product is known as a ______.
Which of the following statements about carbon monoxide in the air is correct?
During an experiment, iron nails are placed in copper sulphate solution, and a reddish-brown deposit forms on the nails. What does this observation demonstrate about the type of chemical reaction and the substances involved?
When dilute Hydrochloric acid (HCl) reacts with Sodium Hydrogen Carbonate (NaHCO3), which is the product formed along with Sodium chloride (NaCl) and Water (H2O)?
Which metal reacts violently with cold water, producing a metal hydroxide, hydrogen gas, and enough heat for the hydrogen to catch fire?
In the reaction Na2SO4(aq) + BaCl2(aq) → BaSO4(*) + 2NaCl(aq), what will be the actual physical state that can replace (*)?
Important Questions from Chemical Reaction
Which of the following statement is/are true?
I. In physical change new substance is formed. substance is formed.
II. In chemical change no new substance is formed.
Which of the following cells involves similar chemical reactions?
The information not obtained from balanced chemical equation is
Oxygen cannot be obtained by which one of the following methods?
Which is the most reactive metal?
