Why do the actinoids exhibit a higher number of oxidation states than lanthanoids?

Reaction of \(C _6 H _5 CH _2 Br\) with aqueous sodium hydroxide follows

In Kolbe's reaction, phenol undergoes :

Benzene ring in phenol is expected to give the characteristic substitution or replacement reactions i.e. halogenation, nitration, sulphonation, alkylation etc. In these reactions, the attacking reagent is electrophile. The phenolic group activates the ortho and para positions in the ring due to conjugation. Disubstitution reactions are quite fast as the electron density in the ring has increased considerably. Phenols do not respond to nucleophilic substitution reactions as it is influenced by phenolic group.

Minor product in above reaction is:

For a fixed volume of liquid solvent, the solubility of a gaseous solute depends upon......
(A) Nature of the gas.
(B) Pressure at constant temperature.
(C) Temperature at constant pressure.
(D) Nature of solvent.
Choose the correct answer from the options given below:

Answer the question on the basis of passage given below :
Adsorption is a surface phenomenon and it differs from absorption which occurs throughout the body of the substance that absorbs. In physiosorption the attractive forces are mainly van der Waal's forces while in chemisorption ionic/covalent bonds are formed between particles of adsorbent and adsorbate. The catalytic activity of finely divided iron in Haber's process of ammonia manufacture can be explained by adsorption theory. Adsorption being an exothermic process, the heat of adsorption is utilised in enhancing the rate of the reaction. Adsorption has many applications being used in gas masks, control of humidity, chromatograph separation, curing diseases etc.
Chromatography is based on:

Which of the following have lowest value of pK, in their aqueous solution?

Which of the following is a straight chain polysaccharide composed only of ß-Dglucose units?

If \(\left[\begin{array}{ll}x+y & 4 \\ 1+z & y\end{array}\right]=\left[\begin{array}{ll}2 & 4 \\ 5 & 6\end{array}\right]\), then

If \(\int_0^a 3 x^2 d x=8\), then the value of \(a\) is:

The formation of pomato is an example of:

The maximum value of the function f(x) = \(x^2\) (60 - x) in [20, 80] is:

The solution of the differential equation \((x+1) \frac{d y}{d x}+1-2 e^{-y}=0 ; y(0)=0\) is