select the correct statement set ? (1) Bis - (glycinato) Zinc (II) is optically active
(2) `[NiCl_4]^(2-) and [PtCl_4]^(2-)` differ in shapes
(3) `[Ni(CN)_4]^(2-)and [Ni(CO)_4]` have same magnetic moment
(4) Cis `[Co(NH_3)_2(en)_2]` cannot show optical activity

Options

A. 1,2
B. 1,3
C. 1,2,3
D. 1,3,4

Answer

To solve the question, we need to analyze each statement provided in the options and determine their correctness based on our knowledge of coordination chemistry.

### Step-by-Step Solution:

1. **Statement 1: Bis-(glycinato) Zinc (II) is optically active.**
- **Analysis:** Bis-(glycinato) Zinc (II) has a chelating ligand (glycinate) that can create a chiral environment around the zinc ion. Since it can exist in non-superimposable mirror images, it is optically active.
- **Conclusion:** This statement is **correct**.

2. **Statement 2: `[NiCl_4]^(2-)` and `[PtCl_4]^(2-)` differ in shapes.**
- **Analysis:** `[NiCl_4]^(2-)` is a tetrahedral complex due to the presence of a d8 configuration, while `[PtCl_4]^(2-)` is typically square planar due to the d8 configuration of platinum. Therefore, they do differ in shape.
- **Conclusion:** This statement is **correct**.

3. **Statement 3: `[Ni(CN)_4]^(2-)` and `[Ni(CO)_4]` have the same magnetic moment.**
- **Analysis:** Both `[Ni(CN)_4]^(2-)` and `[Ni(CO)_4]` are low-spin complexes. Nickel in both cases has a d8 configuration and will have no unpaired electrons, making them diamagnetic. Thus, they will have the same magnetic moment (which is zero).
- **Conclusion:** This statement is **correct**.

4. **Statement 4: Cis `[Co(NH_3)_2(en)_2]` cannot show optical activity.**
- **Analysis:** The cis isomer of `[Co(NH_3)_2(en)_2]` can have a plane of symmetry, which means it does not have non-superimposable mirror images and thus cannot be optically active.
- **Conclusion:** This statement is **correct**.

### Final Conclusion:
All four statements are correct. Therefore, the correct statement set is **1, 2, 3, and 4**.