Choose the correct options:
Order of Acidic strength is based on the experimental value of pka value of given acid
This question involves comparing the relative strengths of acids and bases, and solubility trends of sulfates. Let's analyze each option step by step:
In acetic acid (a weak acid and leveling solvent), the acidic strength order depends on the extent of dissociation. Perchloric acid (HClO4) is the strongest due to high polarity and weak conjugate base. HCl is stronger than H2SO4 and HNO3 because acetic acid differentiates their strengths better than water. The order is correct.
For alkali metal hydroxides, basic strength increases down the group. This is due to decreasing lattice energy and ionization enthalpy, making the release of OH- easier. The order is correct.
In pyridine derivatives, alkyl groups at ortho positions increase basicity by inductive effect but steric hindrance can reduce it. 2,6-dimethylpyridine has high basicity due to inductive effect. 2-methylpyridine is stronger than pyridine. However, 2-t-butyl pyridine has severe steric hindrance, reducing basicity below pyridine. The correct order should be: 2,6-dimethylpyridine > 2-methylpyridine > Pyridine > 2-t-butyl pyridine. Thus, this option is incorrect.
For sulfate salts of alkaline earth metals, solubility decreases down the group due to decreasing hydration energy compared to lattice energy. The correct order is: MgSO4 > CaSO4 > SrSO4 > BaSO4. This option reverses the order, so it is incorrect.
Options 1 and 2 are correct, while options 3 and 4 are incorrect.
Acid-Base Strength: Depends on factors like bond polarity, stability of conjugate base, and solvent effects. For acids, lower pKa means stronger acid. For bases, higher pKb means weaker base.
Solubility Trends: For sulfates, solubility decreases with increasing atomic number due to lattice energy dominating over hydration energy.
Steric Effects: In organic bases, bulky groups near the basic site can hinder protonation, reducing basicity.
Amongst the following, the total number of compounds soluble in aqueous NaOH is
