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Mobile App Problem 3
$$ \begin{aligned} &\text { Point out the oxidation number of } \mathrm{C} \text { in the following : }\\\ &\mathrm{CH}_{4}, \mathrm{C}_{3} \mathrm{H}_{8}, \mathrm{C}_{2} \mathrm{H}_{6}, \mathrm{C}_{4} \mathrm{H}_{10}, \mathrm{CO}, \mathrm{CO}_{2} \text { and } \mathrm{HCO}_{3}^{-}, \mathrm{CO}_{3}^{2-} \end{aligned} $$
Problem 5
Select the nature or type of redox change in the following reactions: (ii) \(2 \mathrm{Cu}^{+} \longrightarrow \mathrm{Cu}^{2+}+\mathrm{Cu}^{0}\) (b) \(\quad \mathrm{Cl}_{2} \longrightarrow \mathrm{ClO}^{-}+\mathrm{Cl}^{-}\) (c) \(2 \mathrm{KClO}_{3} \stackrel{\Delta}{\longrightarrow} 2 \mathrm{KCl}+3 \mathrm{O}_{2}\) (d) \(\quad\left(\mathrm{NH}_{4}\right)_{2} \mathrm{Cr}_{2} \mathrm{O}_{7} \longrightarrow \mathrm{N}_{2}+\mathrm{Cr}_{2} \mathrm{O}_{3}+4 \mathrm{H}_{2} \mathrm{O}\) (e) \(10 \mathrm{FeSO}_{4}+2 \mathrm{KMnO}_{4}+8 \mathrm{H}_{2} \mathrm{SO}_{4} \longrightarrow 2 \mathrm{MnSO}_{4}+5 \mathrm{Fe}_{2}\left(\mathrm{SO}_{4}\right)_{3}+\) \(\mathrm{K}_{2} \mathrm{SO}_{4}+8 \mathrm{H}_{2} \mathrm{O}\) (f) \(5 \mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4}+2 \mathrm{KMnO}_{4}+3 \mathrm{H}_{2} \mathrm{SO}_{4} \longrightarrow \mathrm{K}_{2} \mathrm{SO}_{4}+2 \mathrm{MnSO}_{4}+\) \(10 \mathrm{CO}_{2}+8 \mathrm{H}_{2} \mathrm{O}\)
Problem 7
Identify the substance acting as oxidunt or reductant if any in the following: (i) \(\mathrm{AICl}_{3}+3 \mathrm{~K} \longrightarrow \mathrm{Al}+3 \mathrm{KCI}\) (ii) \(\mathrm{SO}_{2}+2 \mathrm{H}_{2} \mathrm{~S} \longrightarrow 3 \mathrm{~S}+\mathrm{H}_{2} \mathrm{O}\) (iii) \(\mathrm{BaCl}_{2}+\mathrm{Na}_{2} \mathrm{SO}_{4} \longrightarrow \mathrm{BaSO}_{4}+2 \mathrm{NaCl}\) (iv) \(3 \mathrm{I}_{2}+6 \mathrm{NaOH} \longrightarrow \mathrm{NalO}_{3}+5 \mathrm{NaI}+3 \mathrm{H}_{2} \mathrm{O}\)
Problem 8
Write the half reactions for the following redox reactions: (a) \(2 \mathrm{Fe}^{3+}{ }_{\text {(aq. })}+2 \mathrm{I}_{(\mathrm{aq})} \longrightarrow 2 \mathrm{Fe}^{2+}{ }_{\text {(aq.) }}+\mathrm{I}_{2(\mathrm{aq} .)}\) (b) \(\mathrm{Zn}_{(\mathrm{s})}+2 \mathrm{H}_{(\text {aq. })}^{+} \longrightarrow \mathrm{Zn}^{2+}\) (aq.) \(+\mathrm{H}_{2(\mathrm{~g})}\) (c) \(\mathrm{Al}_{(\mathrm{s})}+3 \mathrm{Ag}^{+}{ }_{\text {(aq.) }} \longrightarrow \mathrm{Al}_{\text {(aq.) }}^{3+}+3 \mathrm{Ag}_{(\mathrm{s})}\)
