The study of plants, plant life cycles, photosynthesis, plant parts, etc. is under botany (study of plants).
Density is Mass per Volume
so
0,8765 g/ml = Mass of Benzene / 250 ml
Mass of Benzene = 219,125 gram
so 250 ml of benzene is equal to 219,125 gram
Percent yield of the equation at above condidtions will be 42.4%
if the scientist finds anything that does not match, they have to carry out further tests
it can guide the consumer's judgement purchase decision on too gently on what the believe the product may contain.