Question

Heating \( \text{Ba(NO}_3\text{)}_2 \) produces:

• A. \( \text{N}_2 \)
• B. \( \text{BaO} + \text{NO}_2 + \text{O}_2 \)
• C. \( \text{N}_2\text{O} \)
• D. \( \text{NO}_2 \)

Hint:

All alkaline earth metal nitrates decompose on heating to give a metal oxide, brown fumes of \( \text{NO}_2 \), and \( \text{O}_2 \). In contrast, alkali metal nitrates (except \( \text{LiNO}_3 \)) decompose to give metal nitrites and oxygen gas.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The thermal decomposition of metal nitrates depends on the position of the metal in the electrochemical series and its polarizing power.
Most group 2 (alkaline earth metal) nitrates decompose upon heating to yield the corresponding metal oxide, nitrogen dioxide gas, and oxygen gas.

Step 2: Key Formula or Approach:
The general chemical equation for the thermal decomposition of an alkaline earth metal nitrate is:
\[ 2\text{M(NO}_3\text{)}_2 \xrightarrow{\Delta} 2\text{MO} + 4\text{NO}_2 + \text{O}_2 \]
where M represents a group 2 element such as Beryllium, Magnesium, Calcium, Strontium, or Barium.

Step 3: Detailed Explanation:
Barium (Ba) belongs to group 2 of the periodic table.
When barium nitrate, \( \text{Ba(NO}_3\text{)}_2 \), is strongly heated, it undergoes thermal decomposition.
The balanced chemical equation for this reaction is:
\[ 2\text{Ba(NO}_3\text{)}_2 \xrightarrow{\Delta} 2\text{BaO} + 4\text{NO}_2\uparrow + \text{O}_2\uparrow \]
The products formed are Barium oxide (BaO), Nitrogen dioxide (\( \text{NO}_2 \), a brown gas), and Oxygen (\( \text{O}_2 \), a colorless gas).
Therefore, heating barium nitrate produces \( \text{BaO} + \text{NO}_2 + \text{O}_2 \).

Step 4: Final Answer:
Heating \( \text{Ba(NO}_3\text{)}_2 \) produces \( \text{BaO} + \text{NO}_2 + \text{O}_2 \).