Assertion. The oxidation number of platinum in Zeise's salt is + 4.
Reason. Zeise's salt is non-ionic complex.

Options

A. If both assertion and reason are true, but reason is not the true explanation of the assertion
B. If both assertion and reason are true, but reason is not the true explanation of the assertion
C. If assertion is true, but reason is false
D. If both assertion and reason are false

Explanation

To solve the problem, we need to analyze both the assertion and the reason provided in the question.

### Step 1: Determine the oxidation number of platinum in Zeise's salt.

1. **Identify the components of Zeise's salt**: The formula for Zeise's salt is K[PtCl3(C2H4)]. Here, K represents potassium, Pt represents platinum, Cl represents chlorine, and C2H4 represents ethylene (an alkyne).

2. **Assign known oxidation states**:
- Potassium (K) has an oxidation state of +1.
- Each chlorine (Cl) has an oxidation state of -1. Since there are three chlorine atoms, their total contribution is -3.
- Ethylene (C2H4) is a neutral ligand, so it has an oxidation state of 0.

3. **Set up the equation**: The overall charge of the complex ion [PtCl3(C2H4)] is 0 (since it is part of a neutral compound with K+). Therefore, we can set up the equation:
\[ \text{Oxidation state of Pt} + \text{(oxidation state of Cl)} + \text{(oxidation state of C2H4)} = 0 \]
Substituting the known values:
\[ x + (-3) + 0 = 0 \]
where \( x \) is the oxidation state of platinum.

4. **Solve for x**:
\[ x - 3 = 0 \implies x = +3 \]

### Conclusion for Step 1:
The oxidation number of platinum in Zeise's salt is +3, not +4 as stated in the assertion.

### Step 2: Analyze the reason provided.

1. **Understanding the nature of Zeise's salt**: The question states that Zeise's salt is a non-ionic complex. However, we need to check if it actually forms ions in solution.

2. **Dissociation in aqueous solution**: When Zeise's salt dissolves in water, it dissociates into K+ and the complex ion [PtCl3(C2H4)].
\[ K[PtCl3(C2H4)] \rightarrow K^+ + [PtCl3(C2H4)]^- \]
This indicates that Zeise's salt does produce ions in solution.

### Conclusion for Step 2:
Since Zeise's salt dissociates into ions in solution, it is classified as an ionic complex rather than a non-ionic complex.

### Final Conclusion:
- The assertion that the oxidation number of platinum in Zeise's salt is +4 is **false**.
- The reason that Zeise's salt is a non-ionic complex is also **false**.

Thus, both the assertion and the reason are incorrect.