Question

Which of the following is the strongest base? 1)Sc(OH)3 2)La(OH)3 3) Lu(OH)3 4) Yb(OH) ​

Answer 1

Answer:

answer is option 2

Explanation:

as moving down the group metallic character increases

Answer 2

The strongest base among the given substances is Lanthanum hydroxide.

• The elements, Lanthanum, Ytterbium, and Lutetium are lanthanides and belong to the same period.
• Due to Lanthanide contraction, that is a decrease in atomic size across the lanthanide series, the ionic character of lanthanides decreases from Lanthanum to Lutetium.
• As ionic character decreases, the basicity also decreases.
• So among the given three hydroxides of the lanthanide series, Lanthanum hydroxide is the most basic compound.
• Scandium and Lanthanum belong to the same group and as Lanthanum has a greater atomic size than scandium, ionization energy is less for Lanthanum.
• So it is easy to form lanthanum ion than scandium ion. As ionic character increases, basicity increases.
• Hence, Lanthanum hydroxide is the strongest base among the given compounds.