Answer :
Nitrification is a biological process in soil where ammonia (NH₃) or ammonium ions (NH₄⁺) are converted into nitrite ions (NO₂⁻) by bacteria, and further, the nitrite ions are converted into nitrate ions (NO₃⁻) by different bacteria. This process is very important in the nitrogen cycle, which is a critical component for soil fertility and agriculture.
Let's evaluate each option:
A. This option does not indicate any chemical reaction. It simply displays the molecular formula for water (H₂O) and nitrogen gas (N₂), and indicates the presence of bacteria in the soil. This does not correspond to the nitrification process.
B. This option shows the progression from NH₄⁺, which is ammonium, to NO₂⁻, which is nitrite, and finally to NO₃⁻, which is nitrate. This sequence accurately reflects the nitrification process, where ammonium is first oxidized to nitrite, and then nitrite is further oxidized to nitrate, both steps facilitated by different types of bacteria.
C. This option depicts a completely different process. [tex]\( N_2(g) + 3H_2(g) \rightarrow 2NH_3(g) \)[/tex] is actually the chemical equation for the Haber process, where nitrogen gas (N₂) is chemically combined with hydrogen gas (H₂) under high pressure and temperature to form ammonia (NH₃). This is a process used for industrial ammonia production and is not related to nitrification.
D. The symbols in this option do not correspond to any real chemical species and appear to be a typographical error. NO and N₂O are real compounds—nitric oxide and nitrous oxide, respectively—but "NO," "NO," and "41" don't make chemical sense in the context of nitrification.
The correct answer is:
B. NH₄⁺ → NO₂⁻ → NO₃⁻ (bacteria in the soil)
Let's evaluate each option:
A. This option does not indicate any chemical reaction. It simply displays the molecular formula for water (H₂O) and nitrogen gas (N₂), and indicates the presence of bacteria in the soil. This does not correspond to the nitrification process.
B. This option shows the progression from NH₄⁺, which is ammonium, to NO₂⁻, which is nitrite, and finally to NO₃⁻, which is nitrate. This sequence accurately reflects the nitrification process, where ammonium is first oxidized to nitrite, and then nitrite is further oxidized to nitrate, both steps facilitated by different types of bacteria.
C. This option depicts a completely different process. [tex]\( N_2(g) + 3H_2(g) \rightarrow 2NH_3(g) \)[/tex] is actually the chemical equation for the Haber process, where nitrogen gas (N₂) is chemically combined with hydrogen gas (H₂) under high pressure and temperature to form ammonia (NH₃). This is a process used for industrial ammonia production and is not related to nitrification.
D. The symbols in this option do not correspond to any real chemical species and appear to be a typographical error. NO and N₂O are real compounds—nitric oxide and nitrous oxide, respectively—but "NO," "NO," and "41" don't make chemical sense in the context of nitrification.
The correct answer is:
B. NH₄⁺ → NO₂⁻ → NO₃⁻ (bacteria in the soil)
