First, we need to find the moles of sodium acetate trihydrate NaCH3COO3H2O in 10.0 g.The molar mass of NaCH3COO3H2O is: 22.99 g/mol for Na + 12.01 g/mol for C + 3 1.01 g/mol for H + 2 16.00 g/mol for O + 3 18.02 g/mol for 3H2O = 136.08 g/molNow, we can find the moles of NaCH3COO3H2O:moles = mass / molar mass = 10.0 g / 136.08 g/mol = 0.0735 molNext, we need to find the heat released when the sodium acetate trihydrate dissolves in water. We can use the heat of solution for this:q_solution = moles heat of solution = 0.0735 mol -7126 J/mol = -524.1 JNow, we need to find the heat absorbed by the solution as it cools from 25C to 15C. We can use the specific heat capacity and the mass of the solution for this:q_cooling = mass specific heat capacity Tmass of the solution = 100.0 mL 1.0 g/mL = 100.0 gT = 15C - 25C = -10Cq_cooling = 100.0 g 4.18 J/gC -10C = -4180 JFinally, we can find the heat of crystallization by adding the heat released during the dissolution and the heat absorbed during cooling:q_crystallization = q_solution + q_cooling = -524.1 J + -4180 J = -4704.1 JTherefore, the heat of crystallization when 10.0 g of sodium acetate trihydrate is dissolved in 100.0 mL of water and the solution is allowed to cool to 15C is approximately -4704.1 J.