Question

Zinc metal reacts with hydrochloric acid according to the following balanced equation. Zn(s)+2HCl(aq)→ZnCl2(aq)+H2(g) When 0.106 g of Zn(s) is combined with enough HCl to make 52.3 mL of solution in a coffee-cup calorimeter, all of the zinc reacts, raising the temperature of the solution from 22.4 ∘C to 24.2 ∘C.

Find ΔHrxn for this reaction as written. (Use 1.0 g/mL for the density of the solution and 4.18 J/g⋠∘C as the specific heat capacity.)

ΔHrxn = _____kJ/mol