List of top Chemistry Questions asked in COMEDK UGET

The EMF of the cell \(Al/Al^{3+}(0.01M) \parallel Fe^{2}+(0.02M)/Fe\) is 1.209 V. The EMF of the cell can be increased by
For a given reaction of the type \( \frac{3}{5}X(aq) \rightarrow \frac{1}{2}Y(aq) + Z(g) \), the correct expression for the rate of disappearance of \(X\) with reference to \(Y\) is}
Two statements, One Assertion [A] and the other Reason [R] are given. Identify the correct option.
Assertion [A]: The decreasing order of the acidic character of the following is \(B>D>A>C\).
Reason [R]: Fluorine has larger \(-I\) effect than Cl and Br.
\(X \rightarrow 2Y\) is a first order reaction where \(1.0 \, \text{mol/L}\) of the reactant yields \(0.4 \, \text{mol/L}\) of \(Y\) in 200 minutes. Calculate the half-life period of the reaction in minutes.
The following results were obtained during study of the reaction \(2NO(g) + Cl_2(g) \rightarrow 2NOCl(g)\). Determine the value of \([X]\) in mol/L.
Two statements, one Assertion (A) and the other Reason (R) are given. Choose the correct option.
Assertion: 2-aminoethanoic acid and p-aminobenzene sulphonic acid can exist as Zwitter ions while p-aminobenzoic acid cannot.
Reason: When the acid group is a relatively strong proton donor and the \(-NH_2\) group is sufficiently basic it can accept a \(H^+\) ion from the acid group to form the dipolar ion.
Match the reactions of glucose given in Column I with the major product formed in the reaction as in Column II.
The conductivity of \(0.01\ M\) solution of \(CH_3COOH\) at 298 K is \(1.65 \times 10^{-4}\ S cm^{-1}\). What is the \(pK_a\) value of the acid if \(\lambda^0(H^+)\) and \(\lambda^0(CH_3COO^-)\) are \(349.1\ Scm^2 mol^{-1}\) and \(40.9\ Scm^2 mol^{-1}\) respectively?
A certain gas absorbs photon of wavelength \(4.0 \times 10^{-7} \, m\) and emits radiation at two wavelengths. If one of the emissions occurs at \(7.5 \times 10^{-7} \, m\), what is the wavelength at which the second emission occurs?
Cyclohexanol undergoes a series of reactions as given. Identify compound (iv).
\[ C_6H_{11}OH + CrO_3 \rightarrow (i) + C_6H_5MgI \rightarrow (ii) + \text{dil. }HCl \rightarrow (iii) + \text{Conc. }H_3PO_4 \rightarrow (iv) \]
Identify X, the final product formed when 2 moles of ethanal undergoes the following series of reactions with reagents (i) to (iv).
\[ \mathrm{CH_3CHO \xrightarrow[(ii)\ HCl]{(i)\ dil.\ NaOH} \xrightarrow{(iii)\ NaBH_4} \xrightarrow{(iv)\ Cr_2O_7^{2-}/H^+}{} [X]} \]
Match the structures in Column I with their correct IUPAC names given in Column II.
Which one of the following options represents the decreasing order of oxidation number of the central atom in:
\[ \mathrm{Cr_2O_7^{2-}, \; CrO_2^{-}, \; MnO_4^{-}, \; BrO_3^{-}} \]
Two statements, one Assertion (A) and the other Reason (R) are given. Choose the correct option.
Assertion (A): Maltose, a disaccharide, is a reducing sugar and is obtained by the partial hydrolysis of starch in presence of the enzyme diastase.
Reason (R): Hydrolysis of one mole of Maltose gives one mole each of \( \alpha\text{-D-Glucose} \) and \( \beta\text{-D-Fructose} \).
What is the spin only magnetic moment of the metal ion in P and the oxidation number of Sulphur in the oxidised product Z?
Choose the correct statement.
Arrange the following in the decreasing order of their \(pK_a\) values.
Given that the standard enthalpy of combustion of \(C(s)\) and \(CS_2(l)\) are \(-393.3\) and \(-1108.76 \, \text{kJ/mol}\) respectively and the standard enthalpy of formation of \(CS_2\) is \(128.02 \, \text{kJ/mol}\). What is \(\Delta H_f^\circ\) of \(SO_2\)?
Which one of the following statements is correct?
Benzene diazonium chloride when warmed with water gives a compound, whose sodium salt when reacted with allyl bromide gives compound [X]. Identify [X].
An unsaturated hydrocarbon [A] undergoes the following series of reactions. Identify [A].
For a reaction \(X_2(l) + Y_2(g) \rightleftharpoons 2XY(g)\), the \(\Delta H^0\) and \(\Delta S^0\) are \(+29.3 \, \text{kJ/mol}\) and \(104.1 \, \text{J K}^{-1}\text{mol}^{-1}\) respectively at 298 K. Find the free energy change in kJ/mol.
Identify the compound which gives an optically active haloalkane on reaction with \(H_2/Ni\) on heating.
Which one of the following reactions does not give the correct combination of reactants and the major products formed in the reaction?
Match the coordination compounds in Column I having the given type of hybridisation of \(M^{n+}\) ion and magnetic moment as given in Column II.