MCQ
Which one of the following reactions does not involve either oxidation or reduction
  • A
    $VO_2^ + \, \to \,{V_2}{O_3}$
  • B
    $Na\, \to \,N{a^ + }$
  • $CrO_4^{2 - }\, \to \,C{r_2}O_7^{2 - }$
  • D
    $Z{n^{2 + }}\, \to \,Zn$

Answer

Correct option: C.
$CrO_4^{2 - }\, \to \,C{r_2}O_7^{2 - }$
(c) $\mathop {CrO_4^{2 - }}\limits^{ * \,\,\,\,\,\,\,\,\,\,\,\,} \mathop {C{r_2}O_7^{2 - }}\limits^{ * \,\,\,\,\,\,\,\,\,\,\,\,\,} $

$x + [( - 2) \times 4] = - 2$$2x + ( - 2) \times 7 = - 2$$x = 8 - 2 = + 6$$2x = 14 - 2 = 12$,$x = \frac{{12}}{2} = + 6$

In this reaction oxidation and reduction are not involved because there is no change in oxidation number.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Which one of the following arrangements represents the correct order of electron gain enthalpy (with negative sign) of the given atomic species :-
Find correct one
$0.3\,g$ of an organic compound gave $50\,ml$. of nitrogen collected at $300\,K$ and $715 \,mm$ pressure in Dumas method. Calculate the percentage......$\%$ of nitrogen in the  compound (aqueous tension of water at $300\, K$ is $15\, mm$)
$\Delta H$ and $\Delta E$ for the reaction, $Fe _{2} O _{3}( s )+3 H _{2}( g ) \rightarrow 2 Fe ( s )+ H _{2} O (l)$ at constant temperature are related as
Concentrated $HNO _{3}$ reacts with Iodine to give
In which of the following molecule all bond length are same
How many moles of potassium chlorate to be heated to produce $5.6\, litre$ oxygen at $STP$ ?
An aqueous solution of $NaCl$ shows the depression of freezing point of water equal to $0.372\,K$. The boiling point of $BaCl_2$ solution of same molality will be  .........$^oC$ .$[K_f \,(H_2O)= 1.86\,K\,kg\,mol^{-1}$ ; $K_b\,(H_2O) = 0.52\,K\,kg\,mol^{-1} ]$
$2-$ chloro $-2-$ methylpentane on reaction with sodium methoxide in methanol yields :

$(1)\,\,\begin{array}{*{20}{c}}
  {\,\,\,\,\,\,C{H_3}} \\ 
  | \\ 
  {{C_2}{H_5}C{H_2}C - OC{H_3}} \\ 
  | \\ 
  {\,\,\,\,\,\,\,\,C{H_3}} 
\end{array}$

$(2)\,\,\begin{array}{*{20}{c}}
  {{C_2}{H_5}C{H_2}C = C{H_2}} \\ 
  {\,\,\,\,|} \\ 
  {\,\,\,\,\,\,\,\,\,\,C{H_3}} 
\end{array}$

$(3)\,\,\begin{array}{*{20}{c}}
  {{C_2}{H_5}CH = C - C{H_3}} \\ 
  {\,\,\,\,\,\,\,\,\,\,\,|} \\ 
  {\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,C{H_3}} 
\end{array}$

Which statement is correct about $CO_2$. If central atom use $s + P_x$ orbitals in hybridisation
$(i)$ $\pi $ bond will be formed by $P_Y$ and $P_Z$
$(ii)$ molecule can be in $XY$ plane
$(iii)$ molecule can be in $XZ$ plane
$(iv)$ molecule can be in infinite plane
$(v)$ molecule can be in $YZ$ plane
Correct code is