1. A calorimeter contains 500 g of water at 25°C. You place a hand warmer containing 200 g of liquid sodium acetate inside the calorimeter. When the sodium acetate finishes crystallizing, the temperature of the water inside the calorimeter is 39.4°C. The specific heat of water is 4.18 J/g-°C. What is the enthalpy of fusion (Hf) of the sodium acetate? (Show your work.) Where necessary, use q = mHf.

Question

1.	A calorimeter contains 500 g of water at 25°C. You place a hand warmer containing 200 g of liquid sodium acetate inside the calorimeter. When the sodium acetate finishes crystallizing, the temperature of the water inside the calorimeter is 39.4°C. The specific heat of water is 4.18 J/g-°C. What is the enthalpy of fusion (Hf) of the sodium acetate? (Show your work.) Where necessary, use q = mHf.

aaronq · Answer

First find the change in enthalpy from the water data.

$\Delta H_{water}=m_{water}*C^{water}_P*\Delta T_{water}$

(recall $\Delta T=T_f-T_i$)

then use the moles, n, of sodium acetate to find the standard enthalpy:

 $\Delta H_{water}=\Delta H^o_{fusion}*n_{sodium~acetate}$