List of top Questions asked in COMEDK UGET- 2025

Identify the Alkane (molecular formula \( C_8H_{18} \)) which yields only a single monochloride on Chlorination in the presence of sunlight.
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 Br = 80 u)
Match the reactions given in Column I with the major product formed given in Column II.

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 also be called a protein if it has a well-defined conformation of a protein.
An example of disproportionation reaction is :
For a reaction, \( A + B \rightleftharpoons 2C \), \( 1.0 \) 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 \( 1.0\,\text{mol L}^{-1} \). The equilibrium constant for the reaction is \( x/15 \). The value of \( x \) is:
Two statements, one Assertion and the other Reason, are given. Choose the correct option.
Assertion: During the electrolysis of aqueous NaCl, \( Cl_2 \) is liberated at the anode in preference to \( O_2 \) and water gets reduced to \( H_2 \) at cathode.
Reason: The reaction at anode with lower oxidation potential is not preferred due to over potential of oxygen.
The decomposition of \( PH_3 \) follows first order kinetics. The time required for \( \frac{3}{4} \)th of \( PH_3 \) to decompose is \( 75.76\,s \). Calculate the fraction of original amount of \( PH_3 \) which will remain after \( 2.0 \) minutes.
The bond angles in the following molecules decreases in the order \( BF_3, NH_3, PF_3 \) and \( XeF_2 \)
Identify the correct coefficients (a), (b), (c) and (d) in the following equations
\[ \text{i) } xMnO_4^- + (a)\,SO_3^{2-} + (b)\,H^+ \rightarrow xMn^{2+} + (a)\,SO_4^{2-} + (c)\,H_2O \]
\[ \text{ii) } (c)\,S_2O_3^{2-} + (d)\,MnO_4^- + H_2O \rightarrow (d)\,MnO_2 + (b)\,SO_4^{2-} + xOH^- \]
An aqueous solution of volume \( V \) ml contains a non-volatile solute of unknown mass \( W_B \) g and molar mass \( M_B \) g/mol. If the Osmotic pressure of the solution is \( 1.013 \) bar, which one of the following is the mathematical expression to be used to calculate \( W_B \)?
The ratio of \( N_2 \) and \( O_2 \) gases in the atmosphere is \( 4:1 \). The ratio of the mole fractions of the dissolved gases \( N_2:O_2 \) in rain water will be approximately --------. At \( 293\,K \), \( K_H \) for Nitrogen and Oxygen in kbar units are \( 76.48 \) and \( 34.86 \) respectively.
When the temperature of a reaction \( A + B \rightarrow C \) 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 \( W + X \rightarrow Y + Z \) 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 -------- times.
Identify the correct statement.
Two moles of an ideal gas at 1 bar pressure and 298 K is expanded into vacuum to double the volume. The work done is:
For the cell reaction \( 4Br^- + O_2 + 4H^+ \rightarrow 2Br_2 + 2H_2O \) at \( 298\,K \), the \( E^0_{\text{cell}} = 0.16\,V \). What would be the \( K_c \) (Equilibrium constant) value if the reverse reaction were to take place?
The first electron gain enthalpy of oxygen is \( -141 \, \text{kJ mol}^{-1} \), its second electron gain enthalpy is:
An intrinsic semiconductor has equal concentrations of hole and electron which is equal to \(4 \times 10^{8}\,\text{m}^{-3}\). During its conversion to extrinsic semiconductor, concentration of hole increases to \(8 \times 10^{10}\,\text{m}^{-3}\). The new electron concentration is:
Arrange the complex ions in the increasing order of their magnetic moments
\[ \text{A. } [Fe(H_2O)_6]^{2+} \quad \text{B. } [Fe(CN)_6]^{4-} \quad \text{C. } [Fe(CN)_6]^{3-} \quad \text{D. } [FeF_6]^{3-} \]
A capacitor of capacitance \(4\,\mu F\) is charged to a potential of \(24\,V\) and then connected in parallel to an uncharged capacitor of capacitance \(6\,\mu F\). The final potential difference across each capacitor will be:
A uniformly charged conducting sphere of \(0.2\,\text{m}\) diameter has a surface charge density of \(70\,\mu \text{C m}^{-2}\). The electric flux leaving the surface of the sphere is:
Two electric dipoles of dipole moments \(3.9 \times 10^{-30}\,\text{C m}\) and \(5.2 \times 10^{-30}\,\text{C m}\) are placed in two different uniform electric fields of strengths \(16 \times 10^{4}\,\text{N C}^{-1}\) and \(4 \times 10^{4}\,\text{N C}^{-1}\) respectively. What is the ratio of maximum torque experienced by the electric dipoles?
An aqueous solution of an electrolyte \( A_3B \) is prepared by dissolving \( 0.5625 \) g in \( 750 \) ml of water and is found to be \( 80\% \) ionised. If \( K_b \) for water is \( 0.52 \, \text{K kg mol}^{-1} \), calculate the boiling point of the solution at \( 1.0 \) atm pressure.