${\mathrm{MnO}}_4^{2-}$ undergoes disproportionation reaction in acidic medium but ${\mathrm{MnO}}_4^{-}$ does not?

Nitric acid reacts with PbO but does not react with PbO₂ , because -

The oxidation state of P in ${\mathrm{HPO}}_3^{2-}$ is-

the oxidation state of P in ${\mathrm{PO}}_4^{3-}$?

The oxidation state of two S-atoms in ${\mathrm{Na}}_2{\mathrm{S}}_2{\mathrm{O}}_3$ is -

$$\begin{gathered} \mathrm{(a}) {\mathrm{E}}_{{\mathrm{K}}^{+}/\mathrm{K} }^{\mathrm{o}}= -2.93 \mathrm{V} ; {\mathrm{E}}_{{\mathrm{Ag}}^{+}/\mathrm{Ag}}^{\mathrm{o}}= 0.80 \mathrm{V} \\ \mathrm{} \end{gathered}$$

$$\begin{gathered} \mathrm{(b}) {\mathrm{E}}_{{\mathrm{Hg}}^{+2}/\mathrm{Hg}}^{\mathrm{o}}= 0.79\mathrm{V}; {\mathrm{E}}_{{\mathrm{Mg}}^{+2}/\mathrm{Mg}}^{\mathrm{o}}= -2.37\mathrm{V} \\ \mathrm{} \end{gathered}$$

$\mathrm{(c}) {\mathrm{E}}_{{\mathrm{Cr}}^{+3}/\mathrm{Cr}}^{\mathrm{o}}=-0.74 \mathrm{V}$

Based on standard electrode potentials given above, what is the correct arrangement for increasing order of reducing power of elements? 

The compound AgF₂ (unstable) acts as a/ an:

Among the following hydrohalic compounds, the best reductant is -

$$\begin{gathered} 1. \mathrm{HCl} \\ 2. \mathrm{HBr} \\ 3. \mathrm{HI} \\ 4. \mathrm{HF} \end{gathered}$$

The incorrect oxidation number of the underlined atom in the following species

Identify the incorrect option.

Identify the reaction from having the top position in the EMF series (standard reduction potential) according to their electrode potential at 298 K.

Standard reduction potentials of the half reactions are given below : 

$F_{2\left(g\right)} + 2e^{-}\to 2{F^{-}}_{\left(aq\right)} ; E° =+2.85 V$

$C{l}_{2\left(g\right)} + 2e^{-}\to 2{C{l}^{-}}_{\left(aq\right)} ; E° =+1.36 V$

$B{r}_{2\left(g\right)} + 2e^{-}\to 2{B{r}^{-}}_{\left(aq\right)} ; E° =+1.06 V$

$I_{2\left(g\right)} + e^{-}\to 2{I^{-}}_{\left(aq\right)} ; E° =+0.53 V$

The strongest oxidizing and reducing agents, respectively, are: 

A solution contains Fe²⁺, Fe³⁺ and I^– ions. This solution was treated with iodine at 35^°C. E° for Fe³⁺/Fe²⁺ is +0.77 V and E° for I₂/2I^– = 0.536 V.
The favourable redox reaction is-

The compound that contains zero oxidation state of Fe :

$a Zn + b N{O}_3^{-} + c{H}^{+} \to d N{H}_4^{+} + e H_{2}O +f Z{n}^{+2}$  ; a , b, c, d, e and f respectively are : 

Which is the best description of the behavior of bromine in the reaction given below:-

${\mathrm{H}}_2\mathrm{O}+{\mathrm{Br}}_2\to \mathrm{HOBr}+\mathrm{HBr}$

Oxidation numbers of A, B and C are + 2, +5 and –2 respectively possible formula of compound is :

A non feasible reaction among the following is : -

Standard electrode potentials are

$F{e}^{+2}/Fe E° = -0.\mathrm{44 }$

$\mathrm{ }F{e}^{+3}/F{e}^{+2} E° =0.77$

If $F{e}^{+2} , F{e}^{+3}$ and Fe  block are kept together, then :- 

The oxidation states(O.S.) of sulphur in the anions ${{\mathrm{SO}}_3}^{2-}, {\mathrm{S}}_2{{\mathrm{O}}_4}^{2-} \mathrm{and} {\mathrm{S}}_2{{\mathrm{O}}_6}^{2-}$ follow the order -

Fluorine reacts with ice as per the following reaction

H₂O(s) + F₂(g) → HF(g) + HOF(g)

This reaction is a redox reaction because-

The oxidation number of sulphur and nitrogen in H₂SO₅ and NO₃^- are respectively-

What will be the formulas for the following compounds

(a) Mercury(II) chloride  and (b) Thallium(I) sulphate

Consider the following reactions:

(a) 6 CO_2(g) + 6H₂O_(l) → C₆H₁₂O_6(aq) + 6O_2(g)

(b) O_3(g) + H₂O_2(l) → H₂O_(l) + 2O_2(g)

It is more appropriate to write these reactions as following because:

(a) 6CO_2(g) + 12H₂O_(l) → C₆H₁₂O_6(aq) + 6H₂O_(l) + 6O_2(g)

(b) O_3(g) + H₂O_2(l) → H₂O_(l) + O_2(g) + O_2(g)

In the manufacture of benzoic acid from toluene, we use alcoholic potassium permanganate as an oxidant because -

Consider the following reactions :

2 S₂O₃^2–_(aq) + I_2(s) → S₄O₆^2–_(aq) + 2I^–_(aq)

S₂O₃^2–_(aq) + 2Br_2(l) + 5H₂O_(l) → 2SO₄^2–_(aq) + 4Br^–_(aq) + 10H⁺_(aq)

The same reductant, thiosulphate react differently with iodine and bromine because-

The correct statement(s) about the given reaction is -

$\stackrel{}{\mathrm{X}}{\mathrm{eO}}_{6\left(\mathrm{aq}\right)}^{4-}+2{{\mathrm{F}}^{-1}}_{\left(\mathrm{aq}\right)}+6{{\mathrm{H}}^{+}}_{\left(\mathrm{aq}\right)}\to \stackrel{}{\mathrm{X}}{\mathrm{eO}}_{3\left(\mathrm{g}\right)}+{\stackrel{}{\mathrm{F}}}_{2\left(\mathrm{g}\right)}+3{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)}$

Consider the following reactions:

Consider the following reactions:

(a) H₃PO_2(aq) + 4AgNO_3(aq) + 2H₂O_(l) → H₃PO_4(aq) + 4Ag_(s) + 4HNO_3(aq)

(b) H₃PO_2(aq) + 2CuSO_4(aq) + 2H₂O_(l) → H₃PO_4(aq) + 2Cu_(s) + H₂SO_4(aq)

$$\begin{gathered} \left(\mathrm{c}\right) {\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CHO}}_{\left(\mathrm{l}\right) }+ 2{{\left[\mathrm{Ag}{\left({\mathrm{NH}}_3\right)}_2\right]}^{+}}_{\left(\mathrm{aq}\right)} + 3{{\mathrm{OH}}^{-}}_{\left(\mathrm{aq}\right)}\to {\mathrm{C}}_6{\mathrm{H}}_5{{\mathrm{COO}}^{-}}_{\left(\mathrm{aq}\right)} + {\mathrm{Ag}}_{\left(\mathrm{s}\right)} + 4{{\mathrm{NH}}_3}_{\left(\mathrm{aq}\right)} +{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)} \\ \left(\mathrm{d}\right) {\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CHO}}_{\left(\mathrm{l}\right)} + 2{{\mathrm{Cu}}^{2+}}_{\left(\mathrm{aq}\right)} + 5{{\mathrm{OH}}^{-}}_{\left(\mathrm{aq}\right)}\to \mathrm{No} \mathrm{change} \mathrm{observed} \end{gathered}$$

Draw the inference about the behaviour of Ag⁺ and Cu²⁺ ions from these reactions 

The oxidising agent and reducing agent in the given reaction are

$$\begin{gathered} 5{\mathrm{P}}_{4\left(\mathrm{s}\right)}+12{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)}+12{{\mathrm{HO}}^{-}}_{\left(\mathrm{aq}\right)}\to \\ 8{\mathrm{PH}}_{3\left(\mathrm{g}\right)}+12{{\mathrm{HPO}}_2^{-}}_{\left(\mathrm{aq}\right)} \end{gathered}$$

The correct statement about the given reaction is-

(CN)_2(g) + 2OH^-_(aq) $\mathbf{\to }$CN^-_(aq) + CNO^-_(aq) + H₂O_(l)

The ${\mathrm{Mn}}^{3+}$ ion is unstable in solution and undergoes disproportionation reaction to give ${\mathrm{Mn}}^{2+}, {\mathrm{MnO}}_2 \mathrm{and} {\mathrm{H}}^{+}$ ion. The balanced ionic equation for the reaction is-