CBSE 12th Chemistry Delhi Set 1 - 2023
Paper was held on
Tue, Feb 28, 2023 5:00 AM
Chemistry
Which of the following molecules has a chiral centre correctly labelled with an asterisk (*) ?
View Question Which of the following alcohols will not undergo oxidation?
View Question A voltaic cell is made by connecting two half cells represented by half equations below:
$$\begin{aligned}
& \mathrm{Sn}
View Question Four half reactions I to IV are shown below:
I. $$2 \mathrm{Cl}^{-} \rightarrow \mathrm{Cl}_2+2 \mathrm{e}^{-}$$
II. $$4
View Question Which property of transition metals enables them to behave as catalysts?
View Question In the two tetrahedral structures of dichromate ion
View Question 1 mole of liquid A and 2 moles of liquid $$B$$ make a solution having a total vapour pressure 40 torr. The vapour pressu
View Question Which of the following would not be a good choice for reducing nitrobenzene to aniline?
View Question If molality of a dilute solution is doubled, the value of the molal elevation constant $$\left(\mathrm{K}_{\mathrm{b}}\r
View Question Hydrolysis of sucrose is called
View Question Which one of the following has lowest $$\mathrm{pK}_{\mathrm{a}}$$ value?
View Question Which of the following cell was used in Apollo space programme?
View Question The following experimental rate data were obtained for a reaction carried out at $$25^{\circ} \mathrm{C}$$
$$A_{(g)}+B_{
View Question The magnetic moment of $$\left[\mathrm{NiCl}_4\right]^{2-}$$
[Atomic number : $$\mathrm{Ni}=28$$ ]
View Question Assertion (A): Proteins are polymers of $$\alpha$$-amino acids connected by a peptide bond.
Reason (R): A tetrapeptide c
View Question Assertion (A): For a zero order reaction the unit of rate constant and rate of reaction are same.
Reason (R) : Rate of r
View Question Assertion (A): Acetic acid but not formic acid can be halogenated in presence of red $$\mathrm{P}$$ and $$\mathrm{Cl}_2$
View Question Assertion (A): Trans $$\left[\mathrm{Cr} \mathrm{Cl}_2(\mathrm{ox})_2\right]^{3-}$$ shows optical isomerism.
Reason (R):
View Question (a) (i) What should be the signs (positive/ negative) for $$\mathrm{E}_{\text {Cell }}^0$$ and $$\Delta \mathrm{G}^0$$ f
View Question What happens to the rate constant $$k$$ and activation energy $$E_a$$ as the temperature of a chemical reaction is incre
View Question (a) Which of the following species cannot act as a ligand? Give reason.
$$\mathrm{OH}^{-}, \mathrm{NH}_4^{+}, \mathrm{CH
View Question Why is boiling point of o-dichlorobenzene higher than p-dichlorobenzene but melting point of para isomer is higher than
View Question For the pair phenol and cyclohexanol, answer the following
(a) Why is phenol more acidic than cyclohexanol?
(b) Give one
View Question (a) (i) Draw the zwitter ion structure for sulphanilic acid.
(ii) How can the activating effect of $$-\mathrm{NH}_2$$ gr
View Question Give the reaction of glucose with hydrogen cyanide. Presence of which group is confirmed by this reaction?
View Question (a) For the reaction
$$2 \mathrm{~N}_2 \mathrm{O}_{5(\mathrm{~g})} \rightarrow 4 \mathrm{NO}_{2(\mathrm{~g})}+\mathrm{O}
View Question (a) On the basic of crystal field theory write the electronic configuration for $$\mathrm{d}^5$$ ion with a strong field
View Question (a) Illustrate Sandmeyer's reaction with an equation.
(b) Explain, why $$\left(\mathrm{CH}_3\right)_2 \mathrm{NH}$$ is m
View Question Give reasons for any 3 of the following observations:
(a) Penta-acetate of glucose does not react with hydroxylamine.
(b
View Question (a) (i) Why is the $$\mathrm{C}-\mathrm{O}$$ bond length in phenols less than that in methanol?
(ii) Arrange the followi
View Question Read the passage carefully and answer the questions that follow :
Nucleophilic Substitution
Nucleophilic Substitution re
View Question Rahul set-up an experiment to find resistance of aqueous $$\mathrm{KCl}$$ solution for different concentrations at $$298
View Question (a) (i) Why is boiling point of $$1 \mathrm{~M} \mathrm{~NaCl}$$ solution more than that of $$1 \mathrm{M}$$ glucose sol
View Question (a) (i) Write the reaction involved in Cannizaro's reaction.
(ii) Why are the boiling point of aldehydes and ketones low
View Question (a) Why is chemistry of actinoids complicated as compared to lanthanoids?
(b) Complete the following reaction and justif
View Question