The oxidation state of N in HNO3 is :

a.) +7

b.) +10

c.) +5

d.) +3

To determine the oxidation state of nitrogen (N) in nitric acid (HNO3), we can analyze the compound's structure and apply some basic rules of oxidation states. The correct answer is a.) +5. Let’s break this down step by step.

Understanding Oxidation States

Oxidation states are a way to keep track of electrons in chemical compounds. They help us understand how atoms bond and interact with each other. Here are some key rules to remember:

• The oxidation state of hydrogen is typically +1.
• The oxidation state of oxygen is usually -2.
• The sum of the oxidation states in a neutral compound must equal zero.

Analyzing HNO3

Now, let’s apply these rules to HNO3:

• In HNO3, we have one hydrogen atom (H), one nitrogen atom (N), and three oxygen atoms (O).
• The oxidation state of hydrogen is +1.
• Each oxygen has an oxidation state of -2, and since there are three oxygen atoms, their total contribution is 3 × (-2) = -6.

Setting Up the Equation

Now, we can set up an equation to find the oxidation state of nitrogen (let's call it x):

x (oxidation state of N) + 1 (from H) + (-6) (from O) = 0

This simplifies to:

x - 5 = 0

Solving for x gives us:

x = +5

Conclusion

Thus, the oxidation state of nitrogen in HNO3 is +5. This means that nitrogen is in a relatively high oxidation state, which is characteristic of its role in strong acids like nitric acid. Understanding oxidation states is crucial for predicting the behavior of compounds in chemical reactions, especially in redox processes.