What is the frequency of a X-ray photon whose momentum is 1.1 x 10-23 kg-ms-2 ?
5 x 1016 Hz
0.5 x 1027 Hz
0.5 x 1018 Hz
5 x 1018 Hz
The magnitude of orbital angular momentum of an electron of azimuthal quantum number 2 is :
B.
Orbital angular momentum =
where l = azimuthal quantum number
The solubility product of Mg(OH)2 at 25°C is 1.4 x 10-11 .What is the solubility of Mg(OH)2 in g/L ?
0.0047 g/L
0.047 g/L
0.0087 g/L
0.087 g/L
The heat of formarion of CO2 is - 393 kJ mol-1 .The amount of heat evolved in the formation of 0.156 kg of CO2 .
- 1393 kJ
+ 1165.5 kJ
+ 1275.9 kJ
- 1165.5 kJ
The bond energy is the energy required to :
dissociate one mole of the substance
dissociate bond in 1 kg of the substance
break one mole of similar bonds
break bonds in one mole of the substance
Heat of neutralisation of an acid with a base is 13. 7 kcal when :
both acid and base are weak
acid is weak and base is strong
both acid and base are strong
acid is strong and base is weak
Hess's law is based on :
law of conservation of mass
law of conservation of energy
enthalpy is a state function
none of the above