Which is the correct sequence in the following properties. For the correct order mark `( T)` and for the incorrect order mark `( F) :`
`{:((a)"Acidity order ":SiF_(4) lt SiCl_(4) lt SiBr_(4) lt Sil,,
(b)"Melting point":NH_(3) gt SbH_(3) gt AsH_(3) gt PH_(3),,),
((c )"Boiling point " :NH_(3) gt SbH_(3) gt AsH_(3) gt PH_(3),
,(d)"Dipole moment order ":NH_(3) gt SbH_(3) gt AsH_(3) gt PH_(3),=,5):}`

Options

A. FTFT
B. TFTF
C. FFTT
D. FFTF

Explanation

To solve the question, we will analyze each property one by one and determine whether the given sequences are correct (T) or incorrect (F).

### Step 1: Analyze Acidity Order
**Given Order:** SiF₄ < SiCl₄ < SiBr₄ < SiI₄

- **Explanation:** Acidity increases with the electronegativity of the halogen. Fluorine is the most electronegative, followed by chlorine, bromine, and iodine. As we move down the group, the size of the halogen increases, leading to decreased acidity due to increased crowding around the silicon atom.
- **Conclusion:** The correct order should be SiI₄ > SiBr₄ > SiCl₄ > SiF₄. Thus, the given order is incorrect.

**Mark:** (F)

### Step 2: Analyze Melting Point Order
**Given Order:** NH₃ > SbH₃ > AsH₃ > PH₃

- **Explanation:** The melting point of these hydrides is influenced by intermolecular hydrogen bonding. NH₃ has strong hydrogen bonds due to the high electronegativity of nitrogen, leading to a higher melting point compared to the others, which have weaker Van der Waals forces.
- **Conclusion:** The order given is correct.

**Mark:** (T)

### Step 3: Analyze Boiling Point Order
**Given Order:** NH₃ > SbH₃ > AsH₃ > PH₃

- **Explanation:** The boiling point is influenced by molecular mass and hydrogen bonding. NH₃ has hydrogen bonding, but SbH₃ has a higher molecular mass and thus a higher boiling point than NH₃. Therefore, the correct order should be SbH₃ > NH₃ > AsH₃ > PH₃.
- **Conclusion:** The given order is incorrect.

**Mark:** (F)

### Step 4: Analyze Dipole Moment Order
**Given Order:** NH₃ > SbH₃ > AsH₃ > PH₃

- **Explanation:** Dipole moment is influenced by the difference in electronegativity. NH₃ has the highest dipole moment due to nitrogen's high electronegativity. As we move down the group, the electronegativity decreases, leading to lower dipole moments in SbH₃, AsH₃, and PH₃.
- **Conclusion:** The order given is correct.

**Mark:** (T)

### Final Summary of Results
- (a) Acidity order: **(F)**
- (b) Melting point: **(T)**
- (c) Boiling point: **(F)**
- (d) Dipole moment order: **(T)**

### Final Answer
The correct sequence is:
- (a) F
- (b) T
- (c) F
- (d) T

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