- 1(current)
Q. No.The bond dissociation energy of B – F in BF3 is 646 kJ mol–1 , whereas that of C – F in CF4 is 515 kJ mol–1. The correct reason for the higher B-F bond dissociation energy as compared to that of C-F is :
1. Smaller size of B-atom as compared to that of C-atom
2. Stronger σ bond between B and F in BF3 as compared to that between C and F in CF4
3. Significant pπ − pπ interaction between B and F in BF3 whereas there is no possibility of such interaction between C and F in CF4
4. Lower degree of pπ − pπ interaction between B and F in BF3 than that between C and F in CF4
| List-I (Metal) |
List-II (Application) |
||
| A. | \(\text{Cs}\) | I. | High-temperature thermometer |
| B. | \(\text{Ga}\) | II. | Water repellent sprays |
| C. | \(\text{B}\) | III. | Photoelectric cells |
| D. | \(\text{Si}\) | IV. | Bulletproof vest |
Choose the most appropriate answer from the options given below:
1. (A)-(III), (B)-(I), (C)-(IV), (D)-(II)
2. (A)-(IV), (B)-(III), (C)-(II), (D)-(I)
3. (A)-(II), (B)-(III), (C)-(IV), (D)-(I)
4. (A)-(I), (B)-(IV), (C)-(II), (D)-(III)
| Statement I: |
The chlorides of beryllium and aluminium have bridged chloride structures, are soluble in organic solvents, and act as Lewis bases. |
| Statement II: |
The hydroxides of beryllium and aluminium dissolve in excess alkali to form beryllate and aluminate ions, respectively. |
| 1. | Both Statement I and Statement II are true |
| 2. | Both Statement I and Statement II are false |
| 3. | Statement I is true but Statement II is false |
| 4. | Statement I is false but Statement II is true |
- 1(current)
Q. No.
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