Magnesium reacts with aqueous hydrochloric acid, HCl(aq)\text{HCl(aq)}HCl(aq), as shown below:
Mg(s)+2HCl(aq)→MgCl2(aq)+H2(g)ΔH=−462 kJ mol−1 \text{Mg(s)} + 2\text{HCl(aq)} \rightarrow \text{MgCl}_2\text{(aq)} + \text{H}_2\text{(g)} \quad \Delta H = -462\text{ kJ mol}^{-1} Mg(s)+2HCl(aq)→MgCl2(aq)+H2(g)ΔH=−462 kJ mol−1A student adds an excess of magnesium to 150.0 cm3150.0\text{ cm}^3150.0 cm3 of 0.500 mol dm−30.500\text{ mol dm}^{-3}0.500 mol dm−3 HCl(aq)\text{HCl(aq)}HCl(aq). The initial temperature is 19.5 ∘C19.5\text{ }^\circ\text{C}19.5 ∘C.
Determine the maximum temperature reached in this reaction. Give your answer to 3 significant figures.
Assume that the specific heat capacity and density of the solution are the same as for water (c=4.18 J g−1 K−1c = 4.18\text{ J g}^{-1}\text{ K}^{-1}c=4.18 J g−1 K−1, and density =1.00 g cm−3= 1.00\text{ g cm}^{-3}=1.00 g cm−3), and that there are no heat losses.
