Which of the following does not have intermolecular hydrogen bonding?

Which of the following statements is NOT correct for $\mathrm{H}_2-\mathrm{O}_2$ fuel cell?

Identify the element reduced in following reaction.

$$\mathrm{Cr}_2 \mathrm{O}_7^{2-}+14 \mathrm{H}^{+}+6 \mathrm{I}^{-} \longrightarrow 2 \mathrm{Cr}^{3+}+3 \mathrm{H}_2 \mathrm{O}+3 \mathrm{I}_2$$

Calculate the pH of buffer solution containing 0.027 M weak acid and 0.054 M of its salt with strong base if $\mathrm{pK}_{\mathrm{a}}$ is 4.2.