Answer: option J: 128 joules
Step-by-step explanation:
1) From the table you try to find which relation best fits the data.
2) Your best first assumption is that the data may fit a proportional relation.
3) To prove that you find the ratio of Energy ouput to Amount of chemicals.
Doing that you find:
20 32 48 60
----- = ------- = ------ = ------ = 4
5 8 12 15
4) Then you have found a direct relation whose ratio is 4 joules / mol. So, you can apply that constant to the number of moles given:
Energy = 4 joules / mol × 32 mol = 128 joules