Questions
The number of equivalents of $Na _{2}S _{2}O _{3}$ required for the volumetric estimation of one equivalent of $Cu^{2+}$ is:
- $1/3$
- $1$
- $3/2$
- $2/3$
A volume of $100 ml$ of $ H _{2}O _{2}$ is oxidized by 100 ml of $ 1 M \ KMnO _{4}$ in acidic medium $ (MnO _{4}^{-}$ reduced to $ Mn^{2+}).$ A volume of $100 ml$ of same $H _{2}O _{2}$ is oxidized by $'V'$ ml of $1 M \ KMnO _{4}$ in basic medium ($ MnO _{4}^{-}$ reduced to $ MnO _{2}).$ The value of $'V'$ is
- $500$
- $100$
- $33.33$
- $166.67$
A solid $PQ$ has rock salt type structure in which $Q$ atoms are the corners of the unit cell. If the body-centered atoms in all the unit cells are missing, the resulting stoichiometry will be
- $PQ$
- $P{Q} _{2}$
- ${ P } _{ 3 }{ Q } _{ 4 }$
- ${ P } _{ 4 }{ Q } _{ 3 }$
In a solid $AB$ of $NaCl$ structure, A atoms occupy the corners of the cubic unit cell. If all the corner atoms are removed then the formula of the unit cell will be
- $A _{4}B _{4}$
- $B$
- $A _{3}B _{4}$
- $AB$
Number of electrons involved in the electrodeposition of 63.5 g of Cu from solution of $ CuSO _{4} $ is:
- $ 6.022\times 10^{23} $
- $ 3.011\times 10^{23} $
- $ 12.044\times 10^{23} $
- $ 6.022\times 10^{23} $
Write balanced half reactions for the following redox reaction:
$Cr _2O _7^{2-} + Fe^{2+}\rightarrow Cr^{3+} + Fe^{3+}$
- Reduction: $6e^-+ 14H^+ + Cr _2O _7^{2-} \rightarrow Cr^{3+} + 7H _2O $
Oxidation: $ \\ Fe^{2+} \rightarrow Fe^{3+} + e^{-}$ - Oxidation: $6e^-+ 14H^+ + Cr _2O _7^{2-} \rightarrow Cr^{3+} + 7H _2O $
Reduction: $ \\ Fe^{2+} \rightarrow Fe^{3+} + e^{-}$ - Reduction: $4e^-+ 14H^+ + Cr _2O _7^{2-} \rightarrow Cr^{3+} + 7H _2O $
Oxidation: $ \\ Fe^{2+} \rightarrow Fe^{3+} + e^{-}$ - Oxidation: $6e^-+ 14H^+ + Cr _2O _7^{2-} \rightarrow Cr^{3+} + 6H _2O $
Reduction: $ \\ Fe^{2+} \rightarrow Fe^{3+} + e^{-}$
Which particles are gained and lost during a redox reaction?
- Protons
- Neutrons
- Electrons
- Positrons
Two half reactions are given as follows:
$2e^{-} + H^{+} + H _5IO _6 \rightarrow IO^{3-} + 3H _2O $
$Cr \rightarrow Cr^{3+} + 3e^{-}$
Final balanced reaction is:
- $3H^{+} + 3H _5IO _6 + 2Cr \rightarrow 2Cr^{3+} + 3IO^{3-} + 9H _2O$
- $5H^{+} + 3H _5IO _6 + 2Cr \rightarrow 2Cr^{3+} + 3IO^{3-} + 10H _2O$
- $3H^{+} + 3H _5IO _6 + 4Cr \rightarrow 4Cr^{3+} + 3IO^{3-} + 9H _2O$
- $3H^{+} + 3H _5IO _6 + 3Cr \rightarrow 3Cr^{3+} + 3IO^{3-} + 9H _2O$
In the reaction, $FeS {2} + KMnO {4} + H^{+} \rightarrow Fe^{3+} + SO {2} + Mn^{2+} + H {2}O$, the equivalent mass of $FeS {2}$ would be equal to______.
- $\text{molar mass}$
- $\dfrac {\text {molar mass}}{10}$
- $\dfrac {\text {molar mass}}{11}$
- $\dfrac {\text {molar mass}}{13}$
How much volume of $0.1M$ $Zn{ \left( Mn{ O } _{ 4 } \right) } _{ 2 }$ is required to react with $50ml$ of $0.2M$ ferrous oxalate. Given ${ MnO } _{ 4 }^{ - }$ reduces into ${ Mn }^{ 2+ }$ in acidic medium.
- $30ml$
- $60ml$
- $40ml$
- None
For the redox reaction $MnO^- _4+C _2O^{3+} _4+H^+\rightarrow Mn^{2+}+CO _2+H _2O$. The correct whole number stoichiometric coefficients of $MnO^- _4, C _2O^{3+} _4$ and $H^+$ are respectively.
- $2.5, 16$
- $16, 5.2$
- $5, 16.2$
- $2, 16.5$
0.2 g of a sample of $
{\text{H}} _{\text{2}} {\text{O}} _{\text{2}}
$ required 10 mL of 1 N $
{\text{KMnO}} _{\text{4}}
$ in a titration in the presence of $
{\text{H}} _{\text{2}} {\text{SO}} _{\text{4}}
$. Purity of $
{\text{H}} _{\text{2}} {\text{O}} _{\text{2}}
$ is:
- 25%
- 85%
- 65%
- 95%
In alkaline medium, $ClO _2$ oxidizes $H _2O _2$ to $O _2$ and is itself reduced to ${ClO} _2^{\displaystyle-}$. Number of moles of $H _2O _2$ oxidized by 1 mole of $ClO _2$ is :
- 1
- 1.5
- 0.5
- 3.5
For the reaction of $MnO _2,+,C _2O _{4}^{2-},+,H^+,\rightarrow,Mn^{2+},+,CO _2,+,H _2O$ the correct whole number stoichiometric coefficients of $MnO _4$ , $C _2$$O _4$ and $H^+$ are respectively :
- 2 , 5 , 16
- 16 , 5 , 2
- 5 , 16 , 2
- 2 , 16 , 5