Nitrogen forms the largest number of oxides as it is capable of forming stable multiple bonds with oxygen. They range of `N_(2)O` (O.S of nitrogen +1) through `NO, N_(2)O_(3),NO_(2),N_(2)O_(4)` "to" `N_(2)O_(5)` (O.S of nitrogen +5). Following points are improtant regarding the study of oxides of nitrogen.
(a) All oxides of nitrogen expect `N_(2)O_(5)` are endothermic as a large amount of energy is required to dissociate the stable molecule of oxygen and nitrogen.
(b) The small electronegativity difference between oxygen and nitrogen make N-O bond easily breakle to give oxygen and hence oxides of nitrogen are said to be better oxidising agents.
(c) Expect `N_(2)O_(5)`, all are gases at ordinary temperature. `N_(2)O_(3)` is stable only at lower temperature (253K).
(d) Expect `N_(2)O` and NO which are neutal oxides, all are acidic oxides which dissolve in water forming coresponding oxy acids.
(e) They are also good example for illustrating the concept of resonance.
The gas which is acidic in nature is :

Options

A. NO
B. `N_2O`
C. `NO_2`
D. both (A) and (C )

Explanation

To determine which gas among the oxides of nitrogen is acidic in nature, we can analyze the information provided step by step.

### Step 1: Identify the Oxides of Nitrogen
The oxides of nitrogen mentioned are:
- \(N_2O\) (oxidation state of nitrogen +1)
- \(NO\) (oxidation state of nitrogen +2)
- \(N_2O_3\) (oxidation state of nitrogen +3)
- \(NO_2\) (oxidation state of nitrogen +4)
- \(N_2O_4\) (oxidation state of nitrogen +4)
- \(N_2O_5\) (oxidation state of nitrogen +5)

### Step 2: Classify the Oxides
From the information given:
- \(N_2O\) and \(NO\) are neutral oxides.
- All other oxides are acidic except for \(N_2O_5\), which is not mentioned as a gas at ordinary temperatures.

### Step 3: Determine the Acidic Nature
Acidic oxides are those that react with water to form acids. The oxides of nitrogen that are acidic include:
- \(N_2O_3\)
- \(NO_2\)
- \(N_2O_4\)

### Step 4: Focus on Gases at Ordinary Temperature
The problem states that all oxides of nitrogen except \(N_2O_5\) are gases at ordinary temperatures. Therefore, we need to focus on the gases that are acidic:
- \(NO_2\) is a brown gas and is known to be acidic as it reacts with water to form \(HNO_2\) (nitrous acid) and \(HNO_3\) (nitric acid).

### Step 5: Conclusion
Among the gases listed, the one that is acidic in nature is \(NO_2\).

### Final Answer
The gas which is acidic in nature is \(NO_2\).

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