Which of the following are the products formed while heating silver nitrate?
a. NO_2, O_2 and Ag_2
b. NO, O_2 and Ag
c. NO_2, O_2 and Ag
d. NO_2 and Ag
The Correct Answer and Explanation is:
The correct answer is: c. NO₂, O₂ and Ag.
Explanation:
When silver nitrate (AgNO₃) is heated, it undergoes thermal decomposition, breaking down into its component elements and compounds. The chemical reaction can be represented as follows:
2AgNO3heat2Ag+O2+2NO2
- Silver (Ag): Silver nitrate decomposes to form silver metal (Ag). Silver is a stable metal and remains in its elemental form after the decomposition.
- Oxygen (O₂): Oxygen is released during the decomposition of silver nitrate. The nitrate ion (NO₃⁻) decomposes, and oxygen is liberated in the process.
- Nitrogen dioxide (NO₂): Nitrogen dioxide is formed as a byproduct of the decomposition of the nitrate ion (NO₃⁻). The nitrogen in silver nitrate reacts to form nitrogen dioxide (NO₂), which is a brown gas with a characteristic color and pungent odor.
Reaction Details:
Silver nitrate decomposes when heated above a certain temperature (usually around 450°C). The nitrate ion (NO₃⁻) is broken down into nitrite ions (NO₂⁻) and oxygen (O₂). The nitrite ions further decompose to produce nitrogen dioxide (NO₂), and the silver cation (Ag⁺) combines with the nitrate to form silver metal (Ag).
Thus, the thermal decomposition of silver nitrate leads to the formation of silver (Ag), oxygen (O₂), and nitrogen dioxide (NO₂), which matches option c. This is a classic example of a decomposition reaction, where a single reactant breaks down into multiple products under heat.
Reactions in Detail:
AgNO3heatAg+NO2+O2
This reaction is significant because nitrogen dioxide (NO₂) is a toxic gas, and silver is often recovered for industrial or laboratory use from silver nitrate through this reaction.