# Chemistry

How much energy in kilojoules is released when 25.0 g of ethanol (C2H5OH) vapor at 93.0 C is cooled to -10 C?

Ethanol has mp = -114.1 oC, bp = 78.3 oC, ΔHvap = 38.56 kJ/mol, and ΔHfus = 4.93 kJ/mol. The molar heat capacity is 112.3 J/(K.mol) for the liquid and 65.6 J/(K.mol) for the vapor

25.0g[(1.7)(93-78.3)+841+2.44(78-(-10))] and got 27.030 kJ but that isn't correct!!

1. 👍 0
2. 👎 0
3. 👁 827
1. q1 = energy released on vapor cooling from 93 C to 78.3 C
q1 = mass ethanol x specific heat ethanol vapor x (Tfinal - Tinitial) note: Tf is 78.3 and Ti is 93.0.

q2 = energy released on changing from vapor at 78.3 to liquid at 78.3
q2 = mass ethanol x heat vaporization

q3 = energy released on lidquid cooling from 78.3 to -10. Use same formula as in q1 but with correct specific heat.

Total energy released = q1 + q2 + q3

1. 👍 0
2. 👎 0
posted by DrBob222
2. 17.83kJ

1. 👍 0
2. 👎 0
posted by Kwame

## Similar Questions

1. ### Chemistry

How much energy (in kilojoules) is released when 26.5 of ethanol vapor at 86.0 is cooled to -12.0? Ethanol has = -114.5 , = 78.4 , = 38.56 and = 4.60 . The molar heat capacity is 113 for the liquid and 65.7 for the vapor

asked by Deborah on June 11, 2010
2. ### Chemistry

For ethanol, C2H5OH, which is mixed with gasoline to make the fuel gasohol, H°f = -277.63 kJ/mol. Based upon data in Table 6.2, and that the density of ethanol is 0.787 g•cm-3, the number of kilojoules released by burning

asked by A on October 16, 2011
3. ### chemistry

How much energy (in kilojoules) is released when 21.0 of ethanol vapor at 94.5 is cooled to -19.0?

asked by chem on September 12, 2011
4. ### Chemistry

How much energy (in kilojoules) is released when 29.0 g of ethanol vapor at 88.0 ∘C is cooled to -10.0 ∘C? Ethanol has mp = -114.5 ∘C, bp = 78.4 ∘C, ΔHvap = 38.56 kJ/mol and ΔHfusion = 4.60 kJ/mol. The molar heat

asked by Sci Guy on January 20, 2017
5. ### Chemistry

How much energy (in kilojoules) is released when 29.0 g of ethanol vapor at 88.0 ∘C is cooled to -10.0 ∘C? Express your answer to two significant figures. q = ______________ kJ Ethanol has mp = -114.5 ∘C, bp = 78.4 ∘C,

asked by Brandon on January 26, 2017
6. ### Chemistry

How much energy (in kilojoules) is released when 26.5g of ethanol vapor at 86.0C is cooled to -12.0C? Ethanol has mp = -114.5C , bp = 78.4C, delta H vap = 38.56 (KJ/mol) and delta H fus = 4.60 (KJ/mol) . The molar heat capacity is

asked by Deborah on June 12, 2010
7. ### Chemistry

Ethanol is a fuel that can be made from corn. How many kJ of heat energy are released when 3.00 kg of ethanol are burned? C2H5OH(l) + 3O2(g) ¨ 2CO2(g) + 3H2O(g) H = -1406.8 kJ/mol

asked by Marcus on April 17, 2010
8. ### chemistry

How do you calculate the energy released when 1 mole of ethanol, C2H5OH, is burned?

asked by william on November 7, 2010
9. ### Chemistry

Ethanol (C2H5OH) melts at -114 oC and boils at 78 oC. The enthalpy of fusion of ethanol is 5.02 kJ/mol, and its enthalpy of vaporization is 38.56 kJ/mol. The specific heat capacity of solid and liquid ethanol are 0.97 and 2.3

asked by RPatel on January 14, 2019
10. ### Chemistry

A 15.0g sample of liquid ethanol, C2H5OH, absorbs 5.13x10^3 J of heat at its normal boiling point, 78.0C. The molar enthalpy of vaporization of ethanol is 39.3kJ/mol. (a) What volume of ethanol vapor is produced? The voume is

asked by David on January 27, 2008

More Similar Questions