Anonymous
Anonymous asked in Science & MathematicsChemistry · 2 months ago

Ethanol (C2H5OH) melts at -114 ∘C and boils at 78 ∘C. The enthalpy of fusion of ethanol is 5.02 kJ/mol, and its enthalpy of vaporization...?

Copy-pasted the problem again into here because it was too long above.

Ethanol (C2H5OH) melts at -114 ∘C and boils at 78 ∘C. The enthalpy of fusion of ethanol is 5.02 kJ/mol, and its enthalpy of vaporization is 38.56 kJ/mol. The specific heat of solid and liquid ethanol are 0.97 J/g⋅K are 2.3 J/g⋅K respectively.

How much heat is required to convert 50.0 g of ethanol at 31 ∘C to the vapor phase at 78 ∘C?

How much heat is required to convert 50.0 g of ethanol at -148 ∘C to the vapor phase at 78 ∘C?

Thanks for all of the help

2 Answers

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  • 2 months ago
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    (50.0 g) x (2.3 J/g⋅K) x (78 - 31) K = 5405 J =

    5.405 kJ to warm the liquid to its boiling point

    (50.0 g EtOH) / (46.0684 g EtOH/mol) x (38.56 kJ/mol) =

    41.85 kJ to vaporize the liquid

    5.405 kJ + 41.85 kJ = 47.3 kJ total

    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

    (50.0 g) x (0.97 J/g⋅K) x (- 114 - (-148)) K = 1649 J =

    1.649 kJ to warm the solid to its melting point

    (50.0 g EtOH) / (46.0684 g EtOH/mol) x (5.02 kJ/mol) = 5.448 kJ to melt the solid

    (50.0 g) x (2.3 J/g⋅K) x (78 - (-114)) K = 22080 J =

    22.080 kJ  to warm the liquid to its boiling point

    (50.0 g EtOH) / (46.0684 g EtOH/mol) x (38.56 kJ/mol) = 41.85 kJ to vaporize the liquid

    1.649 kJ + 5.448 kJ + 22.080 kJ + 41.85 kJ = 71.0 kJ total

  • david
    Lv 7
    2 months ago

    Ethanol (C2H5OH) melts at -114 ∘C and boils at 78 ∘C. The enthalpy of fusion of ethanol is 5.02 kJ/mol, and its enthalpy of vaporization is 38.56 kJ/mol. The specific heat of solid and liquid ethanol are 0.97 J/g⋅K are 2.3 J/g⋅K respectively.

      50 g / 46  =  1.087 mol

    How much heat is required to convert 50.0 g of ethanol at 31 ∘C to the vapor phase at 78 ∘C?   50.0[2.3*(78 - 31)]  +  38,560(1.087)  ///  just use a calculator .. answer will be in joules = = if you want kJ just divide by 1000

    How much heat is required to convert 50.0 g of ethanol at -148 ∘C to the vapor phase at 78 ∘C?  50.0[(148 - 114)(0.97)]  +  5.02(1.087)  +  ]....  I'M TIRED.  I quit, yu try the rest

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