During the combustion of 5.00 g of octane, C8H18, 239.5 kcal (1002 kJ) is released. How many kilocalories are released by the combustion of 19.7 g of C8H18 ?
1 answer
See your other two problems. Don't get confused because you're talking about kJ and kcal. Rethink the problem as "you burn 5.00 pennies and get 239.5 dollars for doing that work. How many dollars can you get by burning 19.7 pennies?