Which statement is not true

Options

A. `Ni(CO_(4)) ` is diamagnetic
B. `BI_(3)` is stronger lewis acid than `BF_(3)`
C. Graphite conducts electricity whereas diamond does not
D. `C Cl_(4)` is hydrolysed whereas `BCl_(3)` is inert

Answer

To solve the question "Which statement is not true?", we will analyze each of the four statements provided and determine their validity step by step.

### Step-by-Step Solution:

1. **Statement 1: NiCO is diamagnetic.**
- **Analysis:**
- Nickel (Ni) has an atomic number of 28. Its electronic configuration is:
\[ \text{Ni: } [\text{Ar}] 4s^2 3d^8 \]
- In the presence of CO, a strong field ligand, the electrons in the d-orbitals will pair up, leading to no unpaired electrons.
- Since there are no unpaired electrons, NiCO is indeed diamagnetic.
- **Conclusion:** This statement is **true**.

2. **Statement 2: Bi3+ is a stronger Lewis acid than BF3.**
- **Analysis:**
- Lewis acids are electron pair acceptors. The ability to act as a Lewis acid increases with the size of the atom because larger atoms can stabilize the positive charge better.
- Bismuth (Bi) is larger than boron (B), and thus Bi3+ can accept electron pairs more readily than BF3.
- **Conclusion:** This statement is **true**.

3. **Statement 3: Graphite conducts electricity, whereas diamond does not.**
- **Analysis:**
- In graphite, each carbon atom is bonded to three other carbon atoms, leaving one free electron per carbon that can move and conduct electricity.
- In diamond, each carbon atom is bonded to four other carbon atoms, resulting in no free electrons available for conduction.
- **Conclusion:** This statement is **true**.

4. **Statement 4: CCl4 is hydrolyzed, whereas BCl3 is inert.**
- **Analysis:**
- CCl4 (carbon tetrachloride) does not hydrolyze because it lacks vacant d-orbitals to accommodate additional electron pairs from water.
- BCl3 (boron trichloride) is electron-deficient and readily hydrolyzes to form B(OH)3 in the presence of water.
- **Conclusion:** This statement is **not true**.

### Final Answer:
The statement that is **not true** is **Statement 4**: "CCl4 is hydrolyzed, whereas BCl3 is inert."