CBSE 12th Chemistry Delhi Set 1 - 2023
CBSE 2023 Previous Year
3 hDuration
70Total Marks
18Questions
1Sections
Instructions
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Paper Structure
Chemistry
Chemistry
Q1.
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Which of the following would not be a good choice for reducing nitrobenzene to aniline?
Q2.
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Which property of transition metals enables them to behave as catalysts?
Q3.
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The following experimental rate data were obtained for a reaction carried out at $$25^{\circ} \mathrm{C}$$
$$A_{(g)}+B_{(g)} \rightarrow C_{(g)}+D_{(g)}$$
Initial $$\mathrm{[A_{(g)}]/mol~dm^{-3}}$$
Initial $$\mathrm{[B_{(g)}]/mol~dm^{-3}}$$
Initial rate/mol $$\mathrm{dm^{-3}s^{-1}}$$
$$3.0 \times 10^{-2}$$
$$2.0 \times 10^{-2}$$
$$1.89 \times 10^{-4}$$
$$3.0 \times 10^{-2}$$
$$4.0 \times 10^{-2}$$
$$1.89 \times 10^{-4}$$
$$6.0 \times 10^{-2}$$
$$4.0 \times 10^{-2}$$
$$7.56 \times 10^{-4}$$
$$\text { What are the orders with respect to } \mathrm{A}_{(\mathrm{g})} \text { and } \mathrm{B}_{(\mathrm{g})} \text { ? }$$
Q4.
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Assertion (A): For a zero order reaction the unit of rate constant and rate of reaction are same.
Reason (R) : Rate of reaction for zero order reaction is independent of concentration of reactant.
Q5.
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Which of the following molecules has a chiral centre correctly labelled with an asterisk (*) ?
Q6.
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1 mole of liquid A and 2 moles of liquid $$B$$ make a solution having a total vapour pressure 40 torr. The vapour pressure of pure $$A$$ and pure $$B$$ are 45 torr and 30 torr respectively. The above solution
Q7.
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If molality of a dilute solution is doubled, the value of the molal elevation constant $$\left(\mathrm{K}_{\mathrm{b}}\right)$$ will be
Q8.
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The magnetic moment of $$\left[\mathrm{NiCl}_4\right]^{2-}$$
[Atomic number : $$\mathrm{Ni}=28$$ ]
Q9.
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Assertion (A): Trans $$\left[\mathrm{Cr} \mathrm{Cl}_2(\mathrm{ox})_2\right]^{3-}$$ shows optical isomerism.
Reason (R): Optical isomerism is common in octahedral complexes involving bidentate ligands.
Q10.
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In the two tetrahedral structures of dichromate ion
Q11.
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Which one of the following has lowest $$\mathrm{pK}_{\mathrm{a}}$$ value?
Q12.
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Assertion (A): Acetic acid but not formic acid can be halogenated in presence of red $$\mathrm{P}$$ and $$\mathrm{Cl}_2$$.
Reason (R): Acetic acid is a weaker acid than formic acid.
Q13.
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Hydrolysis of sucrose is called
Q14.
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Assertion (A): Proteins are polymers of $$\alpha$$-amino acids connected by a peptide bond.
Reason (R): A tetrapeptide contains 4 amino acids linked by 4 peptide bonds.
Q15.
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A voltaic cell is made by connecting two half cells represented by half equations below:
$$\begin{aligned}
& \mathrm{Sn}_{(a q)}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Sn}_{(\mathrm{s})} \mathrm{E}^{\mathrm{o}}=-0.14 \mathrm{~V} \\
& \mathrm{Fe}^{3+}{ }_{(\mathrm{aq})}+\mathrm{e}^{-} \rightarrow \mathrm{Fe}^{2+}{ }_{(\mathrm{aq})} \mathrm{E}^{\mathrm{o}}=+0.77 \mathrm{~V}
\end{aligned}$$
Which statement is correct about this voltaic cell?
Q16.
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Four half reactions I to IV are shown below:
I. $$2 \mathrm{Cl}^{-} \rightarrow \mathrm{Cl}_2+2 \mathrm{e}^{-}$$
II. $$4 \mathrm{OH}^{-} \rightarrow \mathrm{O}_2+2 \mathrm{H}_2 \mathrm{O}+2 \mathrm{e}^{-}$$
III. $$\mathrm{Na}^{+}+\mathrm{e}^{-} \rightarrow \mathrm{Na}$$
IV. $$2 \mathrm{H}^{+}+2 \mathrm{e}^{-} \rightarrow \mathrm{H}_2$$
Which two of these reactions are most likely to occur when concentrated brine is electrolysed?
Q17.
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Which of the following cell was used in Apollo space programme?
Q18.
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Which of the following alcohols will not undergo oxidation?