Of the reactions below, which one is a decomposition reaction?
A) NH4Cl NH3 + HCI
B) 2Mg + O2→2MgO
C) 2N2+3H2 → 2NH3
D) 2CH4+4022CO2 + 4H2O
E) Cd(NO3)2 + Na2S CdS + 2NaNO3
The Correct Answer and Explanation is :
The correct answer is A) NH4Cl → NH3 + HCl.
This is a decomposition reaction, which is a type of chemical reaction where a single compound breaks down into two or more simpler substances. In option A, ammonium chloride (NH4Cl) decomposes into ammonia (NH3) and hydrogen chloride (HCl) when heated. This is a classic example of a thermal decomposition reaction, common among ionic salts containing volatile ions.
To better understand, here’s a breakdown of why A is a decomposition reaction and why the others are not:
- B) 2Mg + O2 → 2MgO: This is a synthesis reaction where magnesium (Mg) and oxygen (O2) combine to form magnesium oxide (MgO). Here, simpler substances combine to form a more complex compound.
- C) 2N2 + 3H2 → 2NH3: This is also a synthesis reaction, known specifically as the Haber process, where nitrogen (N2) and hydrogen (H2) gases react under high pressure and temperature in the presence of a catalyst to form ammonia (NH3).
- D) 2CH4 + 4O2 → 2CO2 + 4H2O: This is a combustion reaction where methane (CH4) burns in the presence of oxygen (O2) to produce carbon dioxide (CO2) and water (H2O).
- E) Cd(NO3)2 + Na2S → CdS + 2NaNO3: This is a double displacement reaction where cadmium nitrate (Cd(NO3)2) reacts with sodium sulfide (Na2S) to form cadmium sulfide (CdS) and sodium nitrate (NaNO3).
Decomposition reactions are important in various industrial and biological processes. They can be induced by heat, light, or chemical means and are crucial for the breakdown of complex materials into simpler ones, facilitating recycling and waste management processes, or even in the digestion of food in biological organisms.
Now, let’s generate an image that visually represents the decomposition reaction of ammonium chloride into ammonia and hydrogen chloride.
Here’s the visual representation of the decomposition reaction of ammonium chloride (NH4Cl) into ammonia (NH3) and hydrogen chloride (HCl). The diagram shows the labeled reactants and products, the direction of the reaction, and the molecular structures, along with a symbol indicating that the reaction is thermally induced. You can see how the complex compound breaks down into simpler ones upon heating.
