| List - IMolecule | List - IIBond enthalpy (kJ mol-1) |
|---|---|
| (A) HCl | (I) 435.8 |
| (B) N2 | (II) 498 |
| (C) H2 | (III) 946.0 |
| (D) O2 | (IV) 431.0 |
Bond enthalpy is the energy required to break one mole of a particular bond in a gaseous substance.
A. HCl: The H-Cl bond enthalpy is approximately 431 kJ mol$^{-1}$ (slightly lower than HBr and higher than HF due to periodic trends down the halogen group). Thus, A-IV.
B. N$_2$: The N≡N triple bond is very strong, with a bond enthalpy of approximately 946 kJ mol$^{-1}$. Thus, B-III.
C. H$_2$: The H-H single bond has a bond enthalpy of approximately 436 kJ mol$^{-1}$. Thus, C-I.
D. O$_2$: The O=O double bond has a bond enthalpy of approximately 498 kJ mol$^{-1}$. Thus, D-II.
Therefore, the correct matching is A-IV, B-III, C-I, D-II.
Identify the correct orders against the property mentioned:
A. H$_2$O $>$ NH$_3$ $>$ CHCl$_3$ - dipole moment
B. XeF$_4$ $>$ XeO$_3$ $>$ XeF$_2$ - number of lone pairs on central atom
C. O–H $>$ C–H $>$ N–O - bond length
D. N$_2$>O$_2$>H$_2$ - bond enthalpy
Choose the correct answer from the options given below:
A sphere of radius R is cut from a larger solid sphere of radius 2R as shown in the figure. The ratio of the moment of inertia of the smaller sphere to that of the rest part of the sphere about the Y-axis is : 
A constant voltage of 50 V is maintained between the points A and B of the circuit shown in the figure. The current through the branch CD of the circuit is :
The current passing through the battery in the given circuit, is: 