Question

A $20.0 \mathrm{mL}$ solution containing $0.2 \mathrm{g}$ impure ${\mathrm{H}}_2{\mathrm{O}}_2$ reacts completely with $0.316 \mathrm{g}$ of ${\mathrm{KMnO}}_4$ in acid solution. The purity of ${\mathrm{H}}_2{\mathrm{O}}_2$ (in $\mathrm{\%}$) is______  (mol. wt. of ${\mathrm{H}}_2{\mathrm{O}}_2=34$; mol. wt. of ${\mathrm{KMnO}}_4=158$)

JEE Main 2020 (04 Sep Shift 1)

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Question

In polythionic acid, ${\mathrm{H}}_2{ \mathrm{S}}_x{\mathrm{O}}_6(x=3$ to $5$) the oxidation state(s) of sulphur is/are:

JEE Main 2021 (27 Aug Shift 1)

Options

• A: $+6$ only
• B: $+5$ only
• C: $0$ and $+5$ only
• D: $+3$ and $+5$ only

Question

$15 \mathrm{mL}$ of aqueous solution of ${\mathrm{Fe}}^{2+}$ in acidic medium completely reacted with $20 \mathrm{mL}$ of $0.03 \mathrm{M}$ aqueous ${\mathrm{Cr}}_2{{\mathrm{O}}_7}^{2-}.$ The molarity of the ${\mathrm{Fe}}^{2+}$ solution is _______ $\times {10}^{-2}\mathrm{M}$ (Round off to the Nearest Integer).

JEE Main 2021 (17 Mar Shift 1)

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Question

In basic medium ${\mathrm{CrO}}_4^{2-}$ oxidises ${\mathrm{S}}_2{\mathrm{O}}_3^{2-}$ to form ${{\mathrm{SO}}_4}^{2-}$ and itself changes into $\mathrm{Cr}{\left(\mathrm{OH}\right)}_4^{-}$.The volume of $0.154{\mathrm{MCrO}}_4^{2-}$ required to react with $40 \mathrm{mL}$ of $0.25{\mathrm{MS}}_2{{\mathrm{O}}_3}^{2-}$ is _____ $\mathrm{mL}.$ (Rounded-off to the nearest integer)

JEE Main 2021 (25 Feb Shift 1)

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Question

When $10 \mathrm{mL}$ of an aqueous solution of ${\mathrm{Fe}}^{2+}$ ions was titrated in the presence of dil ${\mathrm{H}}_2{\mathrm{SO}}_4$ using diphenylamine indicator, $15 \mathrm{mL}$ of $0.02 \mathrm{M}$ solution of ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ was required to get the end point. The molarity of the solution containing ${\mathrm{Fe}}^{2+}$ ions is $\mathrm{x}\times {10}^{-2} \mathrm{M}$. The value of $\mathrm{x}$ is ______. (Nearest integer)

JEE Main 2021 (25 Jul Shift 1)

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Question

$20 \mathrm{mL}$ of $0.02 \mathrm{M}$ hypo solution is used for the titration of $10 \mathrm{mL}$ of copper sulphate solution, in the presence of excess of $\mathrm{KI}$ using starch as an indicator. The molarity of ${\mathrm{Cu}}^{2+}$ is found to be $\_\_\_\_\_\times {10}^{-2}\mathrm{M}$ (nearest integer)

Given : $$\begin{gathered} 2{\mathrm{Cu}}^{2+}+4{\mathrm{I}}^{-}\to {\mathrm{Cu}}_2{\mathrm{I}}_2+{\mathrm{I}}_2 \\ {\mathrm{I}}_2 + 2{\mathrm{S}}_2{\mathrm{O}}_3^{-2} \to 2{\mathrm{I}}^{—} + {\mathrm{S}}_4{\mathrm{O}}_6^{-2} \end{gathered}$$

JEE Main 2022 (26 Jul Shift 2)

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Question

The normality of ${\mathrm{H}}_2{\mathrm{SO}}_4$ in the solution obtained on mixing $100 \mathrm{mL}$ of $0.1\mathrm{M} {\mathrm{H}}_2{\mathrm{SO}}_4$ with $50 \mathrm{mL}$ of $0.1\mathrm{M} \mathrm{NaOH}$ is____$\times {10}^{-1} \mathrm{N}$.

JEE Main 2022 (27 Jul Shift 2)

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Question

A $2.0 \mathrm{g}$ sample containing ${\mathrm{MnO}}_2$ is treated with $\mathrm{HCl}$ liberating ${\mathrm{Cl}}_2$. The ${\mathrm{Cl}}_2$ gas is passed into a solution of $\mathrm{KI}$ and $60.0\mathrm{mL}$ of $0.1{\mathrm{MNaS}}_2{\mathrm{O}}_3$ is required to titrate the liberated iodine. The percentage of ${\mathrm{MnO}}_2$ in the sample is____. Nearest integer)
[Atomic masses (in $\mathrm{u}$) $\mathrm{Mn}=55;\mathrm{Cl}=35.5:\mathrm{O}=16,\mathrm{I}=127,\mathrm{Na}=23,\mathrm{K}=39,\mathrm{S}=32$]

JEE Main 2022 (28 Jun Shift 1)

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Question

Which of the given reactions is not an example of disproportionation reaction?

JEE Main 2022 (26 Jul Shift 1)

Options

• A: $2{\mathrm{H}}_2{\mathrm{O}}_2\to 2{\mathrm{H}}_2\mathrm{O}+{\mathrm{O}}_2$
• B: $2{\mathrm{NO}}_2+{\mathrm{H}}_2\mathrm{O}\to {\mathrm{HNO}}_3+{\mathrm{HNO}}_2$
• C: ${\mathrm{MnO}}_4^{-}+4{\mathrm{H}}^{+}+3{\mathrm{e}}^{-}\to {\mathrm{MnO}}_2+2{\mathrm{H}}_2\mathrm{O}$
• D: $3{\mathrm{MnO}}_4{}^{2-}+4{\mathrm{H}}^{+}\to 2{\mathrm{MnO}}_4{}^{-}+{\mathrm{MnO}}_2+2{\mathrm{H}}_2\mathrm{O}$

Question

Strong reducing and oxidizing agents among the following , respectively, are

JEE Main 2023 (06 Apr Shift 1)

Options

• A:

  ${\mathrm{Ce}}^{3+}$ and ${\mathrm{Ce}}^{4+}$

• B: ${\mathrm{Ce}}^{4+}$ and ${\mathrm{Tb}}^{4+}$
• C: ${\mathrm{Ce}}^{4+}$and ${\mathrm{Eu}}^{2+}$
• D: ${\mathrm{Eu}}^{2+}$ and ${\mathrm{Ce}}^{4+}$

Question

During the reaction of permanganate with thiosulphate, the change in oxidation of manganese occurs by value of $3$. Identify which of the below medium will favour the reaction.

JEE Main 2023 (06 Apr Shift 2)

Options

• A: Both aqueous acidic and neutral
• B: Aqueous neutral
• C: Both aqueous acidic and faintly alkaline
• D: Aqueous acidic

Question

Given below are two statements:
Statement I: In redox titration, the indicators used are sensitive to change in $\mathrm{pH}$ of the solution.
Statement II: In acid-base titration, the indicators used are sensitive to change in oxidation potential.

In the light of the above statements, choose the most appropriate answer from the options given below

JEE Main 2023 (08 Apr Shift 2)

Options

• A: Statement I is correct but Statement II is incorrect
• B: Both Statement I and Statement II are incorrect
• C: Statement I is incorrect but Statement II is correct
• D: Both Statement I and Statement II are correct

Question

Given below are two statements :
Statement (I) : Potassium hydrogen phthalate is a primary standard for standardisation of sodium hydroxide solution.
Statement (II) : In this titration phenolphthalein can be used as indicator.
In the light of the above statements, choose the most appropriate answer from the options given below:

JEE Main 2024 (01 Feb Shift 1)

Options

• A: Both Statement I and Statement II are correct
• B: Statement I is correct but Statement II is incorrect
• C: Statement I is incorrect but Statement II is correct
• D: Both Statement I and Statement II are incorrect