List of top Questions asked in UP Board XII

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.
Write chemical equations of the following reactions:
Write a short note on RNA.
Explain the mechanism of electrophilic substitution in haloarenes with the help of an example.
Explain Valence Bond Theory (VBT) in coordination compounds.
Why does the +3 and +4 oxidation state of Cerium (Ce) remain stable?
Is oxidation of bromide ion into bromine by ferric ion possible?
The boiling point of alcohols increases with the increase in the number of carbon atoms but decreases on branching. Why?
Explain velocity (rate) constant of a reaction.
Explain co-ordination number by giving an example.
Write structural formula of primary, secondary, and tertiary benzylic alcohol.
Four alternatives are given in each part of this question. Choose the correct alternative and write it in your answer-book. Number of moles in 180 g of water is:
Write general electronic configuration of d-block and f-block elements.
Write chemical equations for the reaction of (x) ethanamine with HCl and (y) aniline with \( NaNO_2 \) and dilute HCl at \( 0^\circ C \).
State important applications of phenol.
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 \( HgSO_4 \).
What are amines? Write one differentiating test for primary, secondary, and tertiary amines.
State the role of hormones in our body.
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.
Define specific resistance and conductance of a cell.
46 g ethanol is dissolved in 54 g water. Calculate mole fraction of ethanol and water.
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
Write the difference between Galvanic cell and Electrolytic cell.
Write ions produced in an aqueous solution of \( K_4[Fe(CN)_6] \). What is the oxidation number of \( Fe \) in this compound?
Explain the effect of temperature and concentration on the velocity of a reaction.