List of top Chemistry Questions asked in COMEDK UGET

In which one of the following pairs does the stability of the monovalent ion increase with respect to the molecule, while the magnetic character remains the same for both?

When $9.2 \times 10^{-3} \, kg$ of formic acid is added to $600 \, ml$ of water, the freezing point of water is depressed. If $30\%$ of formic acid undergoes dissociation, what would be the freezing point of the solution? Given $K_f$ of $H_2O = 1.86 \, K \, kg \, mol^{-1}$ and molar mass of formic acid $= 46 \, amu$.

Convert Benzene $\rightarrow$ 3-Bromophenol by choosing appropriate reagents (i) to (v) in the correct sequence.
\[ \text{(i) } NaNO_2/HCl \, (0^\circ C) \] \[ \text{(ii) Conc. } HNO_3/H_2SO_4 \] \[ \text{(iii) } H_2O/283 \, K \] \[ \text{(iv) } Fe/HCl \] \[ \text{(v) } Br_2/Fe \]

An aqueous solution of $CrCl_3 \cdot 6H_2O$ having molar mass $266.5 \, g \, mol^{-1}$, containing $2.665 \, g$ of the solute after processing, when treated with excess of $AgNO_3$, gives $2.87 \, g$ of $AgCl$. Given molar mass of $AgCl = 143.5 \, g \, mol^{-1}$. Choose the correct formula of the compound which gives these results.

Identify the final product $[Z]$ formed when chlorobenzene undergoes the given series of reactions.

0.4 g of propane burns completely at 300 K in a bomb calorimeter. The temperature of the calorimeter and surrounding water rises by $0.4^\circ C$. If the heat capacity of the calorimeter and contents is $24 \, kJ \, K^{-1}$, what is the enthalpy for the reaction? Assume that propane gas shows ideal behaviour.

Two volatile liquids X and Y form an ideal solution at 298 K and have vapour pressures equal to 100 mm and 200 mm of Hg respectively in their pure state. The mole fraction of X in the solution is 0.4 and the mole fraction of Y in the vapour phase is $ \frac{a}{20} $. Calculate the value of $a$.

Match the metals in Column II with their characteristic properties given in Column I.

What volume of $0.2M \, CH_3COOH$ needs to be added to $100 \, ml$ of $0.4M \, CH_3COONa$ solution to prepare a buffer of pH equal to $4.91$? Given that $pK_a$ of $CH_3COOH$ is $4.76$.

Two statements, Assertion and Reason are given. Choose the correct option from the following.
Assertion: In the secondary structure of RNA, double helix structure is formed.
Reason: In the double structure of RNA, two nucleic acid chains are wound about each other and held together by hydrogen bonds between pairs of bases.

Given that the freezing point of benzene is $ 5.48^\circ C $ and its $ K_f $ value is $ 5.12^\circ C/m $, what would be the freezing point of a solution of 20 g of propane in 400 g of benzene?

200 ml of an aqueous solution contains 3.6 g of Glucose and 1.2 g of Urea maintained at a temperature equal to 27$^{\circ}$C. What is the Osmotic pressure of the solution in atmosphere units?
Given Data R = 0.082 L atm K$^{-1}$ mol$^{-1}$
Molecular Formula: Glucose = C$_6$H$_{12}$O$_6$, Urea = NH$_2$CONH$_2$

An inorganic compound W undergoes the following reactions: $ W + \text{Na}_2\text{CO}_3 \xrightarrow{\text{O}_2 / \text{heat}} X + H^+ \xrightarrow{} Y(s) $ $ Y(aq) + \text{KCl} (aq) \xrightarrow{} Z(s) $ Z appears in the form of orange crystals and is used as an oxidising agent in acid medium. Identify the compound W.

A current of 3.0 A is passed through 750 ml of 0.45 M solution of CuSO₄ for 2 hours with a current efficiency of 90\%. If the volume of the solution is assumed to remain constant, what would be the final molarity of CuSO₄ solution?

For a reaction $ 5X + Y \to 3Z $, the rate of formation of Z is $ 2.4 \times 10^{-5} \, \text{mol L}^{-1} \text{s}^{-1} $. Calculate the average rate of disappearance of X.

At 700 K, the Equilibrium constant value for the formation of HI from $ H_2 $ and $ I_2 $ is 49.0. 0.7 mole of HI(g) is present at equilibrium. What will be the concentrations of $ H_2 $ and $ I_2 $ gases if we initially started with HI(g) and allowed the reaction to reach equilibrium at the same temperature?

Identify the final product formed when Toluene undergoes a series of reactions with reagents given in the order:
(i) $ \text{Cl}_2 / \text{Sunlight} $
(ii) $ \text{H}_2\text{O}/373 \, \text{K} $
(iii) Acetophenone / $ \text{OH}^- $ at 293 K

4 statements are given below. Identify the incorrect statement:

(A) Phenol has lower $ pK_a $ value than $ \text{p} $-cresol.
(B) 2-Chlorophenol is more acidic than phenol.
(C) Ortho and para nitrophenols can be separated by steam distillation since $ \text{p} $-Nitrophenol is more steam volatile than $ o $-Nitrophenol.
(D) Phenol on reaction with $ \text{Cr}_2\text{O}_7^{2-} / \text{H}^+ $ yields a conjugated diketone.

A Hydrocarbon $ [A] $ (molecular formula $ C_3H_6 $) on reaction with $ \text{Br}_2/\text{CCl}_4 $ gave $ [B] $. When $ [B] $ is heated with 2 moles of alcoholic KOH, it gave compound $ [C] $. 3 moles of Compound $ [C] $ when passed through red hot Iron tube forms $ [D] $. Identify $ [D] $.

The Enthalpy of combustion of C$_6$H$_6$COOH(s) at 25$^\circ$C and 1.0 atm pressure is -2546 kJ/mol. What is the Internal energy change for this reaction?

Arrange the following redox couples in the increasing order of their reducing strength:
Cu$^{2+}$/Cu$^{+}$ $E^\circ = -0.34$ V
Ag$^+$/Ag $E^\circ = -0.8$ V
Ca$^{2+}$/Ca $E^\circ = +2.87$ V
Cr$^{3+}$/Cr$^{2+}$ $E^\circ = +0.74$ V

Match the Vitamins given in Column I with the diseases caused by their deficiency as given in Column II.

Based on Crystal Field theory, match the Complex ions listed in Column I with the electronic configuration in the d orbitals of the central metal ion listed in Column II.

The Activation energy for the reaction A $\rightarrow$ B + C, at a temperature $T_K$ was 0.04606 RT J/mol. What is the ratio of Arrhenius factor to the Rate constant for this reaction?

Choose the incorrect statement from the following: