energy problem?

Question

The combustion of what volume of ethane (C2H6), measured at 23.0 C and 752 mmHg, would be required to heat 855 g of water from 25.0 C to 98.0 C?

Answer 1

98.0C - 25.0C = 73degC difference 23.0C=296K

855gH2O x 73degC x 1cal/g-degC x 1molC2H6/?cal x 22.4LC2H6/1molC2H6 x 296K/273 x 760mmHg/752mmHg = The Answer

Now all you have to do is to provide the ?cal/mol heat of combustion, plug it in, and you're home free!