Heat of combustion question, plz help! D: (1 Viewer)

[Jiggly_Puff]

'The molar heat of combustion of ethanol is 1,367 kj mol

Assuming 100% effeciency, approximately how much ethanol must be combusted to increase the temperature of 3 kg of water from 20 degrees celcius to boiling point?'

Thanks in advance

 

[ohexploitable]

 

[kr73114]

deltaH= mC deltaT= 3000*4.18*80=1003200J=1003.2kJ
but the given value is 1367kJ/mol
therefore: 1003.2/mol=1367.....by rearranging
no. of moles of ethanol=0.733869787
mass of ethanol= .734 * 46.068=33.8g

 

[Jiggly_Puff]

Thanks guys! :d

 

[ohexploitable]