# Enthalpy Changes [closed]

0.50 g of Mg is added to a 50 mL HCl solution. The temperature increased by 5.2 degree Celsius. Calculate the enthalpy change for the reaction per mole of Mg that reacted.

• What is the concentration of the HCl solution? Did all the Mg react? – Karsten Theis Nov 21 '19 at 4:14

We assume all the Mg reacts, which means that $$\frac{1}{48}$$ mol of Mg reacts with 50 ml
The enthalpy change for $$\frac{1}{48}$$ mol is given by $$\Delta H = mC\Delta T = 50 \times 4.186 \times 5.2 \space J$$
Therefore, the enthalpy change per mole is $$48 \times \Delta H = 52.241 \space kJ \space mol^{-1}$$