Ethanol Questions NEED HELP ANSWERING! (1 Viewer)

[nsbrando]

Q1. Beer contains 5% v/v ethanol vapour. How much ethanol will be present in one dozen 500ml cans of beer?

Q2 a. A sample of ethanol vapour in air has a concentration of 20% v/v. Will such mixture combust in the presence of an ignition source at room temperature? Explain.

b. Write balance equation for the complete combustion of ethanol in air.

c. The molar enthalpy of combustion is -1364 kJ mol^-1. Calculate the heat energy released on the combustion of 100L of pure ethanol.

 

[Amundies]

Q2 b. C2H5OH(l) + 3O2 (g) ---> 2CO2(g) + 3H2O (l)

The states could be wrong, I'm not brilliant with those, but it should be balanced right.

c. moles = volume/molar volume. Therefore, moles = 100/24.79 = 4.033884631 (only round off at RIGHT at the end) moles. Since it releases 1364 kJ of energy per mole (the minus sign only indicates that the reaction is exothermic), for 4.033884631 moles, 4.033884631x1364kJ of energy is released. That is, 5502.22 kJ of energy is released. I think this is right... Didn't actually learn it, but it's sort of common sense.

 

[steero1]

a) 300mL
Q2a)yes as their will be excess air since combustion only requires 1:3 moles of ethanolxygen