Nitrifying and denitrifying bacteria play important roles in the nitrogen cycle - VCE - SSCE Chemistry - Question 4 - 2005 - Paper 1
Question 4
Nitrifying and denitrifying bacteria play important roles in the nitrogen cycle. They are involved in the following reactions.
NH₄⁺(aq) → NO₃⁻(aq) reaction 1
NO₃... show full transcript
Worked Solution & Example Answer:Nitrifying and denitrifying bacteria play important roles in the nitrogen cycle - VCE - SSCE Chemistry - Question 4 - 2005 - Paper 1
Step 1
Reaction 1
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
In reaction 1, ammonium ions (NH₄⁺) are oxidized to nitrite (NO₂⁻) and then to nitrate (NO₃⁻). This process involves the oxidation of ammonium and is carried out by nitrifying bacteria. Therefore, reaction 1 is correctly described as oxidation.
Step 2
Reaction 2
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
In reaction 2, nitrate ions (NO₃⁻) are reduced to nitrogen gas (N₂). This reduction process is facilitated by denitrifying bacteria, which convert nitrates into nitrogen gas, contributing to the nitrogen cycle by releasing nitrogen back into the atmosphere. Hence, reaction 2 is correctly described as reduction.
Step 3
Summary of both reactions
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Combining both analyses, the correct representation of each reaction is:
Reaction 1: oxidation
Reaction 2: reduction
Thus, the alternative that correctly describes both reactions is option D: oxidation for reaction 1 and reduction for reaction 2.
