Commercial cold packs consist of solid ammonium nitrate and water.NH₄NO₃ absorbs 25.69 kJ of heat per mole dissolved in water.In a coffee-cup calorimeter,5.60 g NH₄NO₃ is dissolved in 100.0 g of water at 22.0 $\circ$ C.What is the final temperature of the solution? Assume that the solution has a specific heat capacity of 4.18 J/g.K.

Question

Quizplus · Accepted Answer

The heat absorbed by the dissolution of NH₄NO₃ is calculated using q = m × C × ΔT. The moles of NH₄NO₃ are 5.60 g / 80.04 g/mol = 0.07 mol. The heat absorbed is 0.07 mol × 25.69 kJ/mol = 1.7983 kJ = 1798.3 J. Using q = m × C × ΔT, where m = 105.6 g (mass of solution), C = 4.18 J/g.K, and q = 1798.3 J, we solve for ΔT: ΔT = q / (m × C) = 1798.3 J / (105.6 g × 4.18 J/g.K) = 4.1 K. The final temperature is 22.0°C - 4.1°C = 17.9°C.

Commercial Cold Packs Consist of Solid Ammonium Nitrate and Water ∘\circ∘

Commercial Cold Packs Consist of Solid Ammonium Nitrate and Water $\circ$