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(c) Calcium bromide is an ionic compound.
The table shows the formulae and melting points of caffeine and
任 calcium bromide.
\begin{tabular}{|l|c|c|}
\hline \multicolumn{1}{|c|}{ Name } & Formula & Melting point in \( { }^{\circ} \mathrm{C} \) \\
\hline caffeine & \( \mathrm{C}_{8} \mathrm{H}_{10} \mathrm{~N}_{4} \mathrm{O}_{2} \) & 235 \\
\hline calcium bromide & \( \mathrm{CaBr}_{2} \) & 730 \\
\hline
\end{tabular}
The relative formula mass of calcium bromide is similar to the relative formula mass of caffeine.
Explain why calcium bromide has a much higher melting point than caffeine.
(5)
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