List of top Chemistry Questions asked in CBSE CLASS XII

Which of the following is the slope of the first order reaction in the plot of ln[R] vs. time ?

Alkyl halides undergoing nucleophilic bimolecular substitution reaction involve: 

The correct IUPAC name of \([ \text{Pt}(\text{NH}_3)_2\text{Cl}_2 ]^{2+} \) is:

Furanose ring of fructose is formed due to reaction between :

Write the products of the following reactions:

The charge required for the reduction of 1 mol of MnO$_4^-$ to MnO$_2$ is

Give explanation for each of the following observations:

(a) With the same d-orbital configuration (d4), Mn3+ ion is an oxidizing agent whereas Cr2+ ion is a reducing agent.

(b) Actinoid contraction is greater from element to element than that among lanthanoids.

(c) Transition metals form a large number of interstitial compounds with H, B, C, and N.

(ii) Account for the following:
(I) We cannot determine the order of a reaction by taking into consideration the balanced chemical equation.
(II) A bimolecular reaction may become kinetically first order under a specified condition.
State Faraday’s second law of electrolysis. How much electricity is required in terms of Faraday for the reduction of 1 mole of $Cr_2\text{O}_7^{2-} \text{ to Cr}^{3+}$?
In an electrochemical cell, the following reaction takes place : $2\text{Cu}^{2+} (\text{aq}) + \text{Zn} (\text{s}) \rightarrow 2\text{Cu} (\text{s}) + \text{Zn}^{2+} (\text{aq})$
$E^\circ_{\text{cell}} = 1.28 \, \text{V}$
As the reaction progresses, what will happen to the overall voltage of the cell?
Which among the following is a false statement ?
The synthesis of alkyl fluoride is best carried out by:
The charge required for the reduction of 1 mol of \( MnO_4^- \) to \( MnO_2 \) is
Which is the correct IUPAC name for
$\text{CH}_3$
Reactant ‘A’ underwent a decomposition reaction. The concentration of ‘A’ was measured periodically and recorded in the table given below:
Time (Hours)[A] (M)
00.40
10.20
20.10
30.05
Based on the above data, predict the order of the reaction and write the expression for the rate law.
State Raoult’s law for a solution containing volatile components. Why is the vapour pressure of an aqueous solution of glucose lower than that of water?
0.3 g of acetic acid (Molar mass = 60 g mol\(^{-1}\)) dissolved in 30 g of benzene shows a depression in freezing point equal to 0.45°C. Calculate the percentage association of acid if it forms a dimer in the solution.
(Given: \( K_f \) for benzene = 5.12 K kg mol\(^{-1}\))
Why are haloarenes less reactive towards nucleophilic substitution reactions? How does the presence of nitro (–NO₂) group at ortho- and para-positions in haloarenes increase the reactivity towards nucleophilic substitution reactions?
Complete each synthesis by giving missing starting material, reagent, or products:
synthesis by giving missing starting material, reagent
Draw the structure of the major monohalo product for each of the following reactions:
major monohalo product

Convert Propanoic acid to Ethane

Observe the graph in the given figure and answer the following questions:
linear relationship between log |R0| and time.

(a) Predict the order of reaction.
(b) What is the slope of the curve?
PCl$_3$, 2KCl does not give precipitate of AgCl with AgNO$_3$ solution. Write the structural formula and IUPAC name of the complex.
For the reaction:
2H$_2$O$_2$ $\xrightarrow{I^-}$ 2H$_2$O + O$_2$
Given mechanism:
(I) H$_2$O$_2$ + I$^-$ → H$_2$O + IO$^-$ (slow)
(II) H$_2$O$_2$ + IO$^-$ → H$_2$O + I$^-$ + O$_2$ (fast)
(1) Write rate law for the reaction.
(2) Write the overall order and molecularity of the reaction.

Name the type of isomerism exhibited by the following compounds. Also, draw their corresponding isomers.

(I) \( [\text{Co(NH}_3\text{)}_6][\text{Cr(CN)}_6] \)

(II) \( [\text{Co(en)}_3]^{3+} \)

(III) \( [\text{Co(NH}_3\text{)}_3(\text{NO}_2)_3] \)