Standard electrode potentials are:

$F{e}^{+2}/Fe$ ,$E°$ $=$ $-0.\mathrm{44 }$

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

Choose the correct observation if $F{e}^{+2},$ $F{e}^{+3}$, and Fe  block are kept together:

1. $F{e}^{+3}$ increases 

2. $F{e}^{+3}$ decreases 

3. $\frac{F{e}^{+2}}{F{e}^{+3}}$ remains unchanged 

4. $F{e}^{+2}$ decreases

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:

1. ${\mathrm{S}}_2{{\mathrm{O}}_4}^{2-}<{{\mathrm{SO}}_3}^{2-}<{\mathrm{S}}_2{{\mathrm{O}}_6}^{2-}$

2. ${{\mathrm{SO}}_3}^{2-}<{\mathrm{S}}_2{{\mathrm{O}}_4}^{2-}<{\mathrm{S}}_2{{\mathrm{O}}_6}^{2-}$

3. ${\mathrm{S}}_2{{\mathrm{O}}_4}^{2-}<{\mathrm{S}}_2{{\mathrm{O}}_6}^{2-}<{{\mathrm{SO}}_3}^{2-}$

4. ${\mathrm{S}}_2{{\mathrm{O}}_6}^{2-}<{\mathrm{S}}_2{{\mathrm{O}}_4}^{2-}<{{\mathrm{SO}}_3}^{2-}$

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-

The formulas for the following compounds are: 

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

1. HgCl₂,  Tl₂SO₄

2. Hg₂Cl₂, Tl₂SO₄

3. HgCl₂,  TlSO₄

4. HgCl₂,  Tl₃SO₄

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

(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) 

because:

1. Water molecules are also the product of photosynthesis

2. Water molecules are not a product of photosynthesis.

3. Oxygen molecules are also the product of photosynthesis.

4. Oxygen molecules are not a product of photosynthesis.

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

1. The cost of adding an acid or a base can be reduced.

2. The reactions can proceed at a faster rate.

3. Both '1' and '2'

4. Neither '1' nor '2'

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-

1. Br₂ is a stronger oxidizing agent than I₂

2. I₂ is a stronger oxidizing agent than Br₂

3. Both '1' and '2'

4. Neither '1' nor '2'

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

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

1. ${\mathrm{XeO}}_6^{4-}$ oxidises F^-

2. The oxidation number of F increases from -1  to  zero

3. ${\mathrm{XeO}}_6^{4-}$ is a stronger oxidizing agent that ${\mathrm{F}}^{-}$

4. All of the above.

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 

1. Ag⁺ is a stronger oxidizing agent than Cu²⁺

2. Cu²⁺ is a stronger oxidizing agent than Ag⁺

3. Ag⁺ and Cu²⁺ are reducing agents

4.  Ag⁺ is a reducing agent and Cu²⁺ is an oxidising agent