COMEDK 2025 Evening Shift

Choose the incorrect statement.

Identify $[\mathrm{X}]$ used in the given reaction.
$[\mathrm{X}]+$ Copper $/ 573 \mathrm{~K} \rightarrow[\mathrm{Y}]$
$[\mathrm{Y}] \xrightarrow[\text { (ii) } \mathrm{H}_2 \mathrm{O} / \mathrm{H}^{+}]{\text {(i) } \mathrm{CH}_3 \mathrm{Mg...

What are the intermediates formed during the reactions $A$ and $B$ ?
A. Reimer-Tiemann reaction.
B. Dehydration of alcohols in the slow rate determining step.

Which one of the following is the product $(\mathrm{Z})$ formed at the end of the given reaction:
$$\begin{aligned}
& \text { Propan-1-ol }+\mathrm{SOCl}_2 \rightarrow[\mathrm{X}] \\
& {[\mathrm{X}]+\mathrm{HC} \equiv \mathrm{C}-\mathrm{Na}...

Identify X, Y and Z formed in the reaction:

The ratio of the difference between the radii of $3^{\text {rd }}$ and $4^{\text {th }}$ orbits of the $\mathrm{He}^{+}$and those of $\mathrm{Li}^{2+}$ is:

The number of electrons with azimuthal quantum numbers $l=1$ and $l=2$ for Cr in the ground state electronic configurations are respectively.
[Given: $\mathrm{Cr}(\mathrm{Z}=24)$ ]

Two statements, one Assertion and the other Reason are given. Choose the right option.
Assertion : Insulin is called a protein whereas Glycyl alanine is not called a protein
Reason : A polypeptide with amino acid residue less than 100 can a...

Identify the correct statement.

Which of the following is a water soluble vitamin?

An organic compound $[\mathrm{X}]$ (Molecular formula $\mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_2$ ) reacts with dil. $\mathrm{H}_2 \mathrm{SO}_4$ to form an alcohol [B] and a carboxylic acid [C]. Reaction of compound $[\mathrm{B}]$ with Jon...

The bond angles in the following molecules decreases in the order. $\mathrm{BF}_3, \mathrm{NH}_3, \mathrm{PF}_3$ and $\mathrm{XeF}_2$

Arrange the following in the increasing order of their covalent character.
$\mathrm{CaF}_2 ; \mathrm{CaCl}_2 ; \mathrm{CaBr}_2 ; \mathrm{CaI}_2$

For a reaction,
\(A+B \rightleftharpoons 2 C\)
1.0 mole of $A, 1.5$ mole of $B$ and 0.5 mole of $C$ were taken in a 1 L vessel. At equilibrium, the concentration of $C$ was $1.0 \mathrm{~mol} \mathrm{~L}^{-1}$. The equilibrium constant for ...

Consider the reaction
\(\mathrm{Fe}_2 \mathrm{O}_3(\mathrm{~s})+3 \mathrm{CO}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{Fe}(\mathrm{l})+3 \mathrm{CQ}_2(\mathrm{~g})\)
In accordance with Le-Chatlier's principle, which of the following will n...

The decomposition of $\mathrm{PH}_3$ follows first order kinetics. The time required for $3 / 4^{\text {th }}$ of $\mathrm{PH}_3$ to decompose is 75.76 s . Calculate the fraction of original amount of $\mathrm{PH}_3$ which will remain after...

Choose the correct statement.

During a chemical reaction $\mathrm{X} \rightarrow \mathrm{Y}$, the rates of reaction starting with initial concentrations of X as $4.0 \times 10^{-3} \mathrm{M}$ and $2.0 \times 10^{-3} \mathrm{M}$ are $4.8 \times 10^{-4} \mathrm{~mol} \ma...

When the temperature of a reaction $\mathrm{A}+\mathrm{B} \rightarrow \mathrm{C}$ is increased from 300 K to 310 K the rate constant increases by $12 \%$. What is the Activation energy of the reaction?

The order of a reaction $\mathrm{W}+\mathrm{X} ---- \rightarrow \mathrm{Y}+\mathrm{Z}$ with respect to W is 3 and with respect to X is 1. If the concentrations of both W and X are tripled, the rate of reaction will increase by _________ tim...

Two statements, one Assertion and the other Reason are given. Identify the correct option
Assertion : Primary and secondary amides on treatment with $\mathrm{Br}_2$ and alcoholic NaOH yield primary and secondary amines respectively and the ...

Choose the correct statement from the options given

An optically active compound $[\mathrm{X}]$ (Molecular formula $\mathrm{C}_8 \mathrm{H}_{11} \mathrm{~N}$ ) reacts with $\mathrm{CHCl}_3$ / Ethanolic KOH on heating to form an isocyanide. On reaction with $\mathrm{NaNO}_2 / \mathrm{HCl}$, i...

The maximum polarity and dipole moment among the following is :

Match the reactions given in Column I with the major product formed given in Column II.

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Identify the final product $[\mathrm{Y}]$ in the following reaction.

Arrange the complex ions in the increasing order of their magnetic moments
A. $\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$
B. $\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{4-}$
C. $\left[\mathrm{Fe}(\mathrm{CN})_6\right...

Which of the coordination compounds [(i) to (v)] are used for the following processes :
A: Electroplating
B: Removal of excess copper from human body
C: Estimation of hardness of water
(i) DMG
(ii) $\mathrm{Na}_2 \mathrm{EDTA}$
(iii) Cis-pl...

Which of the following compounds has electrons symmetrically distributed in both $\mathrm{t}_{2 \mathrm{~g}}$ and $\mathrm{e}_{\mathrm{g}}$ orbitals?

Find the correct matches.

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...

The electronic configuration of the element with atomic number 78 is :

Choose the correct metal/ ion from the brackets which -------------------------
A. has chemical reactivity similar to that of the first few members of the Lanthanoids $(\mathrm{Zn}, \mathrm{Ca}, \mathrm{Fe}, \mathrm{Cu})$.
B. has stable $4 ...

For the cell reaction $4 \mathrm{Br}^{-}+\mathrm{O}_2+4 \mathrm{H}^{+} \rightarrow 2 \mathrm{Br}_2+2 \mathrm{H}_2 \mathrm{O}$ at 298 K , the $\mathrm{E}^0$ cell $=0.16 \mathrm{~V}$. What would be the $\mathrm{K}_{\mathrm{c}}$ (Equilibrium c...

For a cell $2 \mathrm{M}_{(\mathrm{S})}+\mathrm{O}_2(\mathrm{~g})+4 \mathrm{H}^{+} \rightarrow 2 \mathrm{M}^{2+}(\mathrm{aq})+2 \mathrm{H}_2 \mathrm{O}_{(\mathrm{l})}$ the $\mathrm{E}^0$ cell $=+1.67 \mathrm{~V}$. When $\left[\mathrm{M}^{2+...

Identify the two incorrect electrochemical reactions shown as taking place in the given cells at the respective electrodes.

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Two statements, one Assertion and the other Reason, are given. Choose the correct option.
Assertion : During the electrolysis of aqueous $\mathrm{NaCl}, \mathrm{Cl}_2$ is liberated at the anode in preference to $\mathrm{O}_2$ and water gets...

When $0.1 \mathrm{~mol} \mathrm{~L}^{-1}$ of KCl was filled in a Conductivity cell the resistance was 80 ohms at 298 K . (Conductivity of 0.1 M KCl at 298 K is $1.29 \mathrm{~S} \mathrm{~m}^{-1}$. The same cell when filled with an unknown e...

Which of the following is the most stable free radical?

The correct order of reactivity of halogens with alkanes is :

The number of grams of bromine that will completely react with 5 g of pentene is :
[Atomic mass of $\mathrm{Br}=80 \mathrm{u}$ ]

Identify the Carbonyl compound which will not be formed when hydration of Alkynes is carried out with dil. $\mathrm{H}_2 \mathrm{SO}_4 / \mathrm{Hg}^{2+}$ at 333 K .
Acetone, Butanal, Ethanal, Butanone.

Which of the following alkene on reductive ozonolysis gives ketones only as the product

Consider the following reaction
\(\text { Propyne }+\mathrm{CH}_3 \mathrm{MgBr} \xrightarrow{\text { dry ether }} \mathbf{X}\)
Identify ' X ' from the following.

Identify the Alkane (molecular formula $\mathrm{C}_8 \mathrm{H}_{18}$ ) which yields only a single monochloride on Chlorination in the presence of sunlight.

What would be the major product formed in the reaction?

Identify the type of reaction:

Choose the incorrect statement from the following.

Match the IUPAC names in Column II with the correct structures given in Column I.

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An aqueous solution of volume V ml contains a non-volatile solute of unknown mass $W_B \mathrm{~g}$ and molar mass $M_B \mathrm{~g} / \mathrm{mol}$. If the Osmotic pressure of the solution is 1.013 bar, which one of the following is the mat...

The ratio of $\mathrm{N}_2$ and $\mathrm{O}_2$ gases in the atmosphere is $4: 1$.
The ratio of the mole fractions of the dissolved gases $\mathrm{N}_2$ : $\mathrm{O}_2$ in rain water will be approximately ........ (At $293 \mathrm{~K}, \mat...