Identify the correct statements about alkali metals
A. The order of standard reduction potential \(\left( M ^{+} \mid M \right)\)for alkali metal ions is \(Na > Rb > Li\)
B. \(CsI\)is highly soluble in water.
C. Lithium carbonate is highly stable to heat.
D. Potassium dissolved in concentrated liquid ammonia is blue in colour and paramagnetic.
E. All the alkali metal hydrides are ionic solids.
Choose the correct answer from the options given below:
Reduction potential and solubility depend on ion size and hydration energy. Alkali metal hydrides are ionic due to electrostatic interactions.
• Statement A: True. The reduction potential follows the order Na > Rb > Li when considering their values.
• Statement B: False. CsI is not highly soluble in water due to weak hydration enthalpy of the large Cs+ ion.
• Statement C: False. Lithium carbonate decomposes on heating.
• Statement D: False. Potassium dissolved in ammonia is blue in colour and paramagnetic due to solvated electrons.
• Statement E: True. Alkali metal hydrides are ionic solids due to strong electrostatic forces.
Considering Bohr’s atomic model for hydrogen atom :
(A) the energy of H atom in ground state is same as energy of He+ ion in its first excited state.
(B) the energy of H atom in ground state is same as that for Li++ ion in its second excited state.
(C) the energy of H atom in its ground state is same as that of He+ ion for its ground state.
(D) the energy of He+ ion in its first excited state is same as that for Li++ ion in its ground state.
A substance 'X' (1.5 g) dissolved in 150 g of a solvent 'Y' (molar mass = 300 g mol$^{-1}$) led to an elevation of the boiling point by 0.5 K. The relative lowering in the vapour pressure of the solvent 'Y' is $____________ \(\times 10^{-2}\). (nearest integer)
[Given : $K_{b}$ of the solvent = 5.0 K kg mol$^{-1}$]
Assume the solution to be dilute and no association or dissociation of X takes place in solution.
Inductance of a coil with \(10^4\) turns is \(10\,\text{mH}\) and it is connected to a DC source of \(10\,\text{V}\) with internal resistance \(10\,\Omega\). The energy density in the inductor when the current reaches \( \left(\frac{1}{e}\right) \) of its maximum value is \[ \alpha \pi \times \frac{1}{e^2}\ \text{J m}^{-3}. \] The value of \( \alpha \) is _________.
\[ (\mu_0 = 4\pi \times 10^{-7}\ \text{TmA}^{-1}) \]