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The reaction between potium metal and chlorine gas is described by the following thermochemical equation: K(s) + ½Cl2(g) = KCl(s) ΔH = –437 kJ mol–1 What will be the enthalpy change (to 2 significant figures) for the reaction when 6.0 g of potium metal reacts with chlorine gas at constant pressure? The relative atomic m of potium is 39. ΔH = to 2 significant figures.