The heating curve for methane, $\ce{CH4}$, is shown below.

How much energy is required to melt 64 g of methane at 90 K? (the molar mass of methane is 16 g/mol.)

Summary Submit

Use the heat of fusion equation:

$$q=m H_{fus}$$

Since the heat of fusion is given as kJ per mole, we will need to convert the mass into moles.

$$q=(\pu{64 g})\left(\frac{\pu{1 mol}}{\pu{16 g}}\right) \left(\frac{\pu{0.94 kJ}}{\pu{1 mol}}\right)$$ $$q = \pu{3.76 kJ}$$