Question

Complete the following reactions,
(i) ${\mathrm{H}}_2\left(\mathrm{g}\right)+\mathrm{M}\mathrm{n}\mathrm{O}\left(\mathrm{s}\right)\stackrel{∆}{\to }\mathrm{M}\mathrm{n}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$
(ii) $\text{CO}\left(\text{g}\right)+{\text{H}}_2\left(\text{g}\right)\underset{\text{Catalyst}}{\overset{\Delta }{\to }}$
(iii) ${\text{C}}_3{\text{H}}_8\left(\text{g}\right)+3{\text{H}}_2\text{O}\left(\text{g}\right)\underset{\text{Catalyst}}{\overset{\Delta }{\to }}$
(iv) $\text{Zn}\left(\text{s}\right)+\text{NaOH}\left(\text{aq}\right)\stackrel{\text{Heat}}{\to }$
After completing the above reactions in the balanced equations the coefficient for H₂(g) will be:

• A. 1, 2, 7, 1
• B. 1, 2, 4, 2
• C. 1, 2, 1, 1
• D. 1, 3, 4, 2

Answer 1

Answer: (A)

(i) ${\mathrm{H}}_2\left(\mathrm{g}\right)+{\mathrm{Mn}}_{}\mathrm{O}\left(\mathrm{s}\right)\stackrel{∆}{\to }{\mathrm{Mn}}_{}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$
(ii) $\text{CO}\left(\text{g}\right)+{\text{2H}}_2\left(\text{g}\right)\underset{\text{Catalyst}}{\overset{\Delta }{\to }}\underset{\text{Methanol}}{{\text{CH}}_3\text{OH}\left(\mathit{\text{l}}\right)}$
(iii) ${\text{C}}_3{\text{H}}_8\left(\text{g}\right)+3{\text{H}}_2\text{O}\left(\text{g}\right)\stackrel{\text{Ni, 1270 K}}{\to }3\text{CO}\left(\text{g}\right)+7{\text{H}}_2\left(\text{g}\right)$
$\text{Zn}\left(\text{s}\right)+\text{2NaOH}\left(\text{aq}\right)\stackrel{\text{Heat}}{\to }\underset{\text{Sod.zincate}}{{\text{Na}}_2{\text{ZnO}}_2\left(\text{aq}\right)}+{\text{H}}_2\left(\text{g}\right)$