.90 dL is 90 mL because 1 dL is 100 mL
Density is found by dividing mass over volume:
d=M/V. In this problem, we know the density, and the mass. Solve the general equation for volume, then enter the values from the problem and evaluate:
d=m/v [multiply v to both sides, then divide d from both sides]
v=m/d
v=83.8g/(2.33g/cm³)
v=35.965 cm³
v=36.0 cm³ to three significant figures (since your given information only has 3 sig figs)
Answer:
The energy of the reactants.
