Given elements are: Indium (In), Thallium (Tl), Aluminum (Al), Lead (Pb), Tin (Sn), and Germanium (Ge).
We need to determine the most stable oxidation states of the elements with the highest and lowest first ionization enthalpies from this group.
Position in the periodic table:
Ionization enthalpy trends:
- Ionization enthalpy generally increases across a period and decreases down a group.
- Among these elements, **Aluminum (Al)** has the highest first ionization enthalpy because it is the lightest and topmost element in its group.
- Thallium (Tl) has the lowest first ionization enthalpy due to its position in Period 6, where the inert pair effect becomes significant.
Oxidation states:
Aluminum (Al), with the highest ionization enthalpy, typically shows a +3 oxidation state. This is the most stable oxidation state for Al, as it readily loses all three valence electrons.
Thallium (Tl), with the lowest ionization enthalpy, shows both +3 and +1 oxidation states. However, due to the **inert pair effect**, the +1 oxidation state is more stable than +3.
This trend is also seen in other heavier p-block elements like Pb and Sn, where the +2 oxidation state becomes more stable compared to the +4 state because of the inert pair effect.
Conclusion:
- The element with the highest first ionization enthalpy is **Aluminum (Al)**, which has a most stable oxidation state of **+3**.
- The element with the lowest first ionization enthalpy is **Thallium (Tl)**, which has a most stable oxidation state of **+1**.
Final Answer:
The final answer is $ (2)\ +4\ \text{and}\ +1 $.
For the reaction, $H_2(g) + I_2(g) \rightleftharpoons 2HI(g)$
Attainment of equilibrium is predicted correctly by:
Match List - I with List - II:
List - I:
(A) Electric field inside (distance \( r > 0 \) from center) of a uniformly charged spherical shell with surface charge density \( \sigma \), and radius \( R \).
(B) Electric field at distance \( r > 0 \) from a uniformly charged infinite plane sheet with surface charge density \( \sigma \).
(C) Electric field outside (distance \( r > 0 \) from center) of a uniformly charged spherical shell with surface charge density \( \sigma \), and radius \( R \).
(D) Electric field between two oppositely charged infinite plane parallel sheets with uniform surface charge density \( \sigma \).
List - II:
(I) \( \frac{\sigma}{\epsilon_0} \)
(II) \( \frac{\sigma}{2\epsilon_0} \)
(III) 0
(IV) \( \frac{\sigma}{\epsilon_0 r^2} \) Choose the correct answer from the options given below:
Consider the following statements:
A. Surface tension arises due to extra energy of the molecules at the interior as compared to the molecules at the surface of a liquid.
B. As the temperature of liquid rises, the coefficient of viscosity increases.
C. As the temperature of gas increases, the coefficient of viscosity increases.
D. The onset of turbulence is determined by Reynolds number.
E. In a steady flow, two streamlines never intersect.
Choose the correct answer from the options given below: