Question

A strip of magnesium metal having a mass of 1.22 g dissolves in 100.0 mL of 6.02 M HCl, which has a density of 1.10 g/mL. The hydrochloric acid is initially at 23.0°C, and the resulting solution reaches a final temperature of 45.5°C. The heat capacity of the calorimeter in which the reaction occurs is 562 J/°C. Calculate ΔH (in kJ/mol) for the reaction under the conditions of the experiment, assuming the specific heat of the final solution is the same as that for water, 4.184 J/g°C. (Report numerical answer 4 significant figures) Mg(s) + 2HCl(aq) -> MgCl2(aq)+ H2(g)

Answer 1

Step-by-step explanation:

- The highlighted text describes an experiment where a strip of magnesium metal with a mass of 1.22 g is dissolved in 100.0 mL of hydrochloric acid (HCl) with a concentration of 6.02 M.

- The density of the HCl solution is given as 1.10 g/mL.

- The initial temperature of the HCl solution is 23.0°C, and the final temperature after the reaction is 45.5°C.

- The heat capacity of the calorimeter used in the experiment is 562 J/°C.

- The goal of the experiment is to calculate the enthalpy change (ΔH) for the reaction between magnesium and hydrochloric acid under the given conditions.

- The balanced chemical equation for the reaction is Mg(s) + 2HCl(aq) -> MgCl2(aq) + H2(g).

- To calculate ΔH, the heat released by the reaction is determined using the temperature change and the heat capacity of the calorimeter.

- The heat capacity of the final solution is assumed to be the same as that of water, which is given as 4.184 J/g°C.

- The enthalpy change is calculated in kJ/mol, which means that the heat released by the reaction needs to be converted to kJ and divided by the number of moles of magnesium used in the reaction.