When a 2.00 g sample of ammonium nitrate (NH₄NO₃) dissolves in 48.0 g of water the temperature changes from 26.57 ° C to 23.50 ° C. Assuming the specific heat of the solution is 4.184 J/g × K, what is the enthalpy change for dissolving 2.00 g of ammonium nitrate in water?

Question

Quizplus · Accepted Answer

The enthalpy change can be calculated using q = mcΔT. Here, m = 50 g (2 g NH4NO3 + 48 g water), c = 4.184 J/g·K, and ΔT = 23.50 - 26.57 = -3.07 K. Thus, q = 50 g × 4.184 J/g·K × (-3.07 K) = -642 J. Since the temperature decreases, the process is endothermic, and the enthalpy change is positive, +642 J.

When a 200 G Sample of Ammonium Nitrate (NH4NO3) Dissolves in 48

When a 200 G Sample of Ammonium Nitrate (NH₄NO₃) Dissolves in 48