Physical Chemistry
Some Basic Concepts of Chemistry
MCQ (Single Correct Answer)
Chemical Equilibrium
MCQ (Single Correct Answer)
Inorganic Chemistry
Periodic Table and Periodicity
MCQ (Single Correct Answer)
Chemical Bonding and Molecular Structure
MCQ (Single Correct Answer)
Hydrogen and It's Compounds
MCQ (Single Correct Answer)
d and f Block Elements
MCQ (Single Correct Answer)
Coordination Compounds
MCQ (Single Correct Answer)
Environmental Chemistry
MCQ (Single Correct Answer)
Organic Chemistry
IUPAC Nomenclatures
MCQ (Single Correct Answer)
General Organic Chemistry
MCQ (Single Correct Answer)
Haloalkanes and Haloarenes
MCQ (Single Correct Answer)
Alcohol, Phenols and Ethers
MCQ (Single Correct Answer)
Aldehyde and Ketone
MCQ (Single Correct Answer)
Carboxylic Acids and Its Derivatives
MCQ (Single Correct Answer)
Compounds Containing Nitrogen
MCQ (Single Correct Answer)
Chemistry in Everyday Life
MCQ (Single Correct Answer)
Practical Organic Chemistry
MCQ (Single Correct Answer)
1
COMEDK 2024 Evening Shift
MCQ (Single Correct Answer)
+1
-0

Identify the correct statement regarding corrosion of iron rod left exposed to atmosphere.

A

The reaction occurring at the cathodic area is:

$$ \mathrm{O}_2(\mathrm{~g})+2 \mathrm{H}_2 \mathrm{O}(\mathrm{l})+4 \mathrm{e} \rightarrow 4 \mathrm{OH}^{-} $$

B

The reaction occurring at the cathodic area is:

$$ \mathrm{O}_2(\mathrm{~g})+4 \mathrm{H}^{+}(\mathrm{aq})+4 \mathrm{e} \rightarrow 2 \mathrm{H}_2 \mathrm{O}(\mathrm{l}) ; \mathrm{E}^0=+1.23 \mathrm{~V} $$

C

Reaction occurring at anodic area is:

$$ 2 \mathrm{H}_2 \mathrm{O}(\mathrm{l}) \rightarrow \mathrm{O}_2(\mathrm{~g})+4 \mathrm{H}^{+}+4 \mathrm{e} $$

D

The overall reaction occurring during the corrosion process is:

$$ 2 \mathrm{Fe}_{(\mathrm{S})}+3 / 2 \mathrm{O}_2(\mathrm{~g})+6 \mathrm{H}^{+} \rightarrow 2 \mathrm{Fe}^{3+}+3 \mathrm{H}_2 \mathrm{O} ; \mathrm{E}^0=-1.23 \mathrm{~V} $$

2
COMEDK 2024 Evening Shift
MCQ (Single Correct Answer)
+1
-0

Given below are 2 statements: Assertion and Reason. Choose the correct option.

Assertion: When Molar conductivity for a strong electrolyte is plotted versus $$\sqrt{C}(\mathrm{~mol} / \mathrm{L})^{1 / 2}$$, a straight line is obtained with intercept equal to Molar conductivity at infinite dilution for the electrolyte and Slope equal to $$-\mathrm{A}$$. All electrolytes of a given type have the same $$\mathrm{A}$$ value.

Reason: At infinite dilution, strong electrolytes of the same type will have different number of ions due to incomplete dissociation.

A
Assertion is correct but Reason is incorrect statement.
B
Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
C
Both Assertion and Reason are incorrect statements.
D
Assertion is incorrect but Reason is correct statement.
3
COMEDK 2024 Evening Shift
MCQ (Single Correct Answer)
+1
-0

What is the quantity of charge, in Faraday units, required for the reduction of 3.5 moles of $$\mathrm{Cr}_2 \mathrm{O} 7^{2-}$$ in acid medium?

A
6.0
B
10.5
C
21.0
D
3.0
4
COMEDK 2024 Evening Shift
MCQ (Single Correct Answer)
+1
-0

A dry cell consists of a moist paste of $$\mathrm{NH}_4 \mathrm{Cl}$$ and $$\mathrm{ZnCl}_2$$ contained in a $$\mathrm{Zn}$$ casing which encloses a Carbon rod surrounded by black $$\mathrm{MnO}_2$$ paste. What is the role of $$\mathrm{ZnCl}_2$$ in it?

A
It prevents pressure being developed in the cell due to $$\mathrm{NH}_3$$ gas formation.
B
It serves as cathode thus permitting Carbon rod to act as anode.
C
It acts as the anode while Carbon rod acts as the cathode.
D
It keeps the contents dry and prevents leakage of electrolyte.
COMEDK Subjects