A beaker contains 150 mL of ethyl alcohol at 23.0 Part A What is the minimum amo

Question

A beaker contains 150 mL of ethyl alcohol at 23.0
Part A
What is the minimum amount of energy that must be removed to produce solid ethyl alcohol?

For uniformity, here are some of the values that you may find useful. Density of alcohol: 789 kg/m3 ; specific heat of alcohol: 2.46 kJ/kgC ; latent heat of vaporization of alcohol: 846 kJ/kg ; latent heat of fusion of alcohol: 109 kJ/kg ; melting point of alcohol: -114 C; boiling point of alcohol: 78.4 C; molar mass of alcohol: 46 g/mol .
Please express your answer in three significant figures.
C
Part A
What is the minimum amount of energy that must be removed to produce solid ethyl alcohol?

For uniformity, here are some of the values that you may find useful. Density of alcohol: 789 kg/m3 ; specific heat of alcohol: 2.46 kJ/kgC ; latent heat of vaporization of alcohol: 846 kJ/kg ; latent heat of fusion of alcohol: 109 kJ/kg ; melting point of alcohol: -114 C; boiling point of alcohol: 78.4 C; molar mass of alcohol: 46 g/mol .
Please express your answer in three significant figures.

Explanation / Answer

minimum amount of energy removed is Q = (m*Sa*dT) +(m*Lf)

initial temparature is T1 = 23C

melting point is -114C

change in temparature is 114+23 = 137C

mass m = density*volume = 789*150*10^-3*10^-3 m^3 = 0.118 kg

Sa = specific heat of alcohol: 2.46 kJ/kgC

Lf = latent heat of fusion of alcohol: 109 kJ/kg

then

minimum amount of energy removed is Q = (m*Sa*dT) +(m*Lf)

Q = (0.118*2.46*1000*137)+(0.118*109*1000) = 52630.36 J = 52.63 kJ

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