Ionisation energies of `Ni` and `Pt` in `Kjmol^(-1)` are given below
`{:(,ubrace((IE)_(1)+(IE)_(2)),ubrace((IE)_(3)+(IE)_(4))),(Ni,2.49,8.80),(Pt,2.60,6.70):}`
So, (select the correct statement)

Options

A. Nickle (II) compounds tend to be thermodynamically more stable than platinum(II)
B. Platinum (IV) compounds tend to be more stable than nickel (IV)
C. (A) & (B) both
D. None is correct

Answer

To solve the question regarding the ionization energies of Nickel (Ni) and Platinum (Pt), we will analyze the provided data step by step.

### Given Data:
The ionization energies (IE) for Ni and Pt are as follows:

- For Nickel (Ni):
- Sum of first and second ionization energies: \( (IE_1 + IE_2) = 2.49 \, \text{Kj/mol} \)
- Sum of third and fourth ionization energies: \( (IE_3 + IE_4) = 8.80 \, \text{Kj/mol} \)

- For Platinum (Pt):
- Sum of first and second ionization energies: \( (IE_1 + IE_2) = 2.60 \, \text{Kj/mol} \)
- Sum of third and fourth ionization energies: \( (IE_3 + IE_4) = 6.70 \, \text{Kj/mol} \)

### Step 1: Compare the sum of first and second ionization energies
- For Ni: \( 2.49 \, \text{Kj/mol} \)
- For Pt: \( 2.60 \, \text{Kj/mol} \)

**Conclusion**: Since \( 2.49 < 2.60 \), it indicates that Ni has a lower energy requirement to remove the first two electrons compared to Pt. This suggests that Ni²⁺ compounds are more thermodynamically stable than Pt²⁺ compounds.

### Step 2: Compare the sum of third and fourth ionization energies
- For Ni: \( 8.80 \, \text{Kj/mol} \)
- For Pt: \( 6.70 \, \text{Kj/mol} \)

**Conclusion**: Since \( 6.70 < 8.80 \), it indicates that Pt has a lower energy requirement to remove the third and fourth electrons compared to Ni. This suggests that Pt⁴⁺ compounds are more stable than Ni⁴⁺ compounds.

### Final Conclusion:
Based on the analysis:
1. Ni²⁺ compounds are more thermodynamically stable than Pt²⁺ compounds.
2. Pt⁴⁺ compounds are more stable than Ni⁴⁺ compounds.

### Answer:
Both statements regarding the stability of Ni²⁺ and Pt⁴⁺ compounds are correct. Therefore, the correct option is that both statements A and B are true.

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