Answer to Question #174602 in General Chemistry for Fidjel

Question

2.02g of solid magnesium metal is placed into 80mL of a 0.60mol/L solution of hydrochloric acid.

The reaction is carried out in a simple calorimeter made of Styrofoam cups. The temperature in the solution changed from 21.0°C to 31.3°C.

According to this information, what is the enthalpy of reaction, in kJ, for the reaction as written?

Mg(s) + 2 HCl(aq) → MgCl₂(aq) + H₂(g)   ΔH = ? kJ.

Answer 1

ΔH = $-$ mcΔT

ΔH = − (80g)(4.19J/g°C)(10.3°C)

Thus ;

ΔH = $-$3.45256 kJ