The human body obtains 955 kj of energy from a candy bar.? if this energy were used to vaporize water at 100.0 ∘c, how much water (in liters) could be vaporized? (assume the density of water is 1.00 g/ml.)

The energy to vaporize the water at its normal boilng point (100°C) is the vaporization latent heat.

The vaporization latent heat of water is 2257 J/ g (you can find it in a textbook, tables or internet).

So, with 955 kJ you can vaporize this amount of water:

[995 kJ * 1000J/kJ ] / 2557 J /g = 389.13 g

Use the density to convert to volume: D = M / V => V = M / D

V = 389.13 g / 1.00 g / ml = 389.13 ml, which rounded to 3 significant figures is 389 ml

389 ml

Most likely a is the answer - because  you generate   38 atp's but also consume an atp.   each atp gives approx. less than 4 kcal so probably a is the closest answer.