Ethanol (c2h5oh) melts at -114â°c. the enthalpy of fusion is 5.02 kj/mol. the specific heats of solid and liquid ethanol are 0.97 j/gk and 2.3 j/gk, respectively. how much heat (kj) is needed to convert 25.0 g of solid ethanol at -135â°c to liquid ethanol at -50â°c?

4.18925 kJ heat is needed to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50°C.

Explanation:

Temperature of Solid

Melting temperature of Solid

Temperature of liquid

Specific heats of solid  ethanol = 0.97 J/gK

Specific heats of liquid ethanol = 2.3 J/gK

Heat required to melt the the 25 g solid at 159 K

= 159 K - 138 K = 21 K

Heat required to melt and raise the temperature of upto 223 K

= 223 K - 159 K  = 64 K

Total heat to convert solid ethanol to liquid ethanol at given temperature :

(1kJ=1000J)

Hence, 4.18925 kJ of heat will be required to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50°C.

these nuts