List of top Questions asked in UP Board XII

Explain the mechanism of electrophilic substitution in haloarenes with the help of an example.
Differentiate between elimination and substitution reactions in haloalkanes by an example.
Write chemical equations of the following reactions:
Explain first-order reaction. The value of velocity (rate) constant \( k \) for a first-order reaction is \( 5 \times 10^{-14} \, \text{s}^{-1} \). Calculate the half-life period of the reaction.
Explain Valence Bond Theory (VBT) in coordination compounds.
Is oxidation of bromide ion into bromine by ferric ion possible?
Explain velocity (rate) constant of a reaction.
Why does the +3 and +4 oxidation state of Cerium (Ce) remain stable?
Explain co-ordination number by giving an example.
Write structural formula of primary, secondary, and tertiary benzylic alcohol.
The boiling point of alcohols increases with the increase in the number of carbon atoms but decreases on branching. Why?
Write chemical equations for the reaction of (x) ethanamine with HCl and (y) aniline with \( NaNO_2 \) and dilute HCl at \( 0^\circ C \).
Write general electronic configuration of d-block and f-block elements.
State important applications of phenol.
State the role of hormones in our body.
Write a short note on Rosenmund reduction. Write only the chemical equation of the reaction of ethyne with water in presence of \( H_2SO_4 \) and \( HgSO_4 \).
State the difference between molecularity of a reaction and order of a reaction. Write the velocity equation for the reaction \( H_2(g) + Cl_2(g) \rightarrow 2HCl(g) \), which is a zero-order reaction.
What are amines? Write one differentiating test for primary, secondary, and tertiary amines.
Write ions produced in an aqueous solution of \( K_4[Fe(CN)_6] \). What is the oxidation number of \( Fe \) in this compound?
Write the difference between Galvanic cell and Electrolytic cell.
Calculate the normality of a solution prepared by dissolving 325 g of anhydrous sodium carbonate (\( Na_2CO_3 \)) in 250 mL of water. Equivalent weight of \( Na_2CO_3 \) is 5
The configuration showing maximum oxidation state is:
Electrode potential of standard hydrogen electrode is:
The true statement for the formula \( K = Ae^{-E_a / RT} \) is:
What is the difference between nuclear fission and nuclear fusion? Explain each of them with the help of an appropriate example. Why is in both incidents the nuclear energy released?