[mkboy21]

I finished up a chem problem and i was wondering if it is right
Heres the problem

4.442 moles of frozen ethanol C2H6O at -205.8C need to be converted to gas at 143.2C. How many kJ of heat are required? Ethanol melts at -114.0C and it boils at 78.00C. qFUS = 109 J/g qVAP=879 j/G Cp --> 2.45 j*g/k

i got

q1= (204.63g)(-144.0 k) (2.45 J*g/k) = -721293.464 J
q2=(204.63g)(109 J/g) = 22304.67 J
q3=(204.63g)(78.00 k)(2.45 J*g/k) = 39104.793 J
q4=(204.63g)((879 J/g) = 179869.71 J
q5=(204.63g)(78.00 k)((2.45 J*g/k_ = 39104.793
q6= -440.90 kJ

Is this correct?

[xiankai]

i dont know why there are so many "q"s but u should be calculating the heat change; in otherwords, the temperature change, and not the temperature given.

[Borek]

Idea is probably:

q1 - heating solid ethanol
q2 - melting it
q3 - heating liquid
q4 - evaporation
q5 - gas heating