Which of the following statements is correct

Options

A. oxidation number of Fe in `[Fe(H_(2)O)_(5)NO]SO_(4)` is +1
B. oxidation number of sodium in sodium amalgam is -1
C. oxidation state of carbon in HCN is + 4
D. All statement are correct

Explanation

To determine which of the given statements is correct regarding oxidation states, we will analyze each statement step by step.

### Step 1: Analyze the first statement about the oxidation state of iron.
- The statement claims that the oxidation number of iron is +1.
- To find the oxidation state of iron in a coordination complex, we can use the "X method" where we let the oxidation state of iron be \( x \).
- The complex is neutral overall, and we know that water is neutral (0 charge).
- If there are five ligands (which are neutral), their contribution to the charge is 0.
- If we have sulfate (SO4) with a charge of -2, we can set up the equation:
\[ x + 0 + (-2) = 0 \]
Simplifying this gives:
\[ x - 2 = 0 \implies x = +2 \]
- Thus, the oxidation state of iron is +2, not +1. Therefore, this statement is **false**.

### Step 2: Analyze the second statement about sodium amalgam.
- The statement claims that sodium in sodium amalgam has an oxidation state of -1.
- Sodium amalgam is a mixture of sodium and mercury (Hg).
- In its elemental state, sodium has an oxidation state of 0.
- Since sodium is in a fused state, it remains in its elemental form, thus its oxidation state is indeed 0, not -1. Therefore, this statement is **false**.

### Step 3: Analyze the third statement regarding carbon in HCl.
- The statement claims that carbon's oxidation state in HCl is +4.
- In HCl, hydrogen (H) is bonded to chlorine (Cl). The typical oxidation state of hydrogen is +1.
- The oxidation state of chlorine is -1.
- To find the oxidation state of carbon, we consider the bonds:
- If we assume carbon is bonded to hydrogen and chlorine, we can set up the equation for carbon's oxidation state \( y \):
\[ y + 1 + (-1) = 0 \]
Simplifying this gives:
\[ y + 0 = 0 \implies y = 0 \]
- Thus, the oxidation state of carbon in HCl is 0, not +4. Therefore, this statement is **false**.

### Conclusion:
After analyzing all three statements, we find that all of them are incorrect. Therefore, none of the statements provided in the question is correct.