7. Redox reactions - Rajasthan Board (RBSE) STD 11 Science Chemistry Questions

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M.C.Q (1 Marks)

Sample Questions

7. Redox reactions questions

One sample from each question group in this chapter. Select any group above to see the full set with answer keys.

Which reaction is $NOT$ a redox reaction?

A
$2 \mathrm{KClO}_3+\mathrm{I}_2 \rightarrow 2 \mathrm{KIO}_3+\mathrm{Cl}_2$
B
$\mathrm{H}_2+\mathrm{Cl}_2 \rightarrow 2 \mathrm{HCl}$
✓
$\mathrm{BaCl}_2+\mathrm{Na}_2 \mathrm{SO}_4 \rightarrow \mathrm{BaSO}_4+2 \mathrm{NaCl}$
D
$\mathrm{Zn}+\mathrm{CuSO}_4 \rightarrow \mathrm{ZnSO}_4+\mathrm{Cu}$

Answer: C.

On balancing the given redox reaction,

$aCr _2 O _7^{2-}+ bSO _3^{2-}( aq )+ cH ^{+}( aq ) \rightarrow 2 aCr ^{3+}( aq )+ bSO _4^{2-}( aq )+\frac{ c }{2} H _2 O ( l )$

the coefficients a, b and $c$ are found to be, respectively-

Answer: B.

Which of the following reactions is the metal displacement reaction? Choose the right option.

A
$2 \mathrm{KClO}_{3} \stackrel{\Delta}{\longrightarrow} 2 \mathrm{KCl}+3 \mathrm{O}_{2}$
✓
$\mathrm{Cr}_{2} \mathrm{O}_{3}+2 \mathrm{Al} \stackrel{\Delta}{\longrightarrow} \mathrm{Al}_{2} \mathrm{O}_{3}+2 \mathrm{Cr}$
C
$\mathrm{Fe}+2 \mathrm{HCl} \rightarrow \mathrm{FeCl}_{2}+\mathrm{H}_{2} \uparrow$
D
$2 \mathrm{~Pb}\left(\mathrm{NO}_{3}\right)_{2} \rightarrow 2 \mathrm{PbO}+4 \mathrm{NO}_{2}+\mathrm{O}_{2} \uparrow$

Answer: B.

What is the change in oxidation number of carbon in the following reaction $?$

$CH_4\, _{( g )}+4 Cl _{2}\,_{( g )} \rightarrow CCl _{4}\,_{( l )}+4 HCl\,_ {( g )}$