How does blood flow from a person's leg back to the person's heart? A Gravity pushes the blood upward.
B Lungs pull the blood upward.
C Contracting leg muscles push the blood upward.
D Contracting heart muscles pull the blood upward.

Salicylic acid is a very important acid. it is used to synthesize the aspirin by treating with acetic anhydride. a 0.2015-g sample of salicylic acid was dissolved in a 100.00-ml volumetric flask, and the solution was diluted to the mark. a 10-ml aliquot of this solution was titrated with standard naoh (0.01130 + 0.2% n) to a phenolphthalein faint pink color end point at 19.81 ml. (a) (calculate the normality of the salicylic acid solution used in the titration. (b) assuming the salicylic acid is pure, what is the equivalent weight of the salicylic acid? practice problems for the final exam (continued) (c) (calculate the inherent error in the determination of the equivalent weight you calculated in part (b). use the following absolute errors in the equipment /glassware when calculating the inherent error. 5.00-ml pipet: + 0.02 ml 100-ml volumetric flask: + 0.08 ml analytical balance: + 0.2 mg 25-ml buret: + 0.03 ml

An atom of which element reacts with an atom of hydrogen to form a bond with the greatest degree of polarity ?

The diagram shows the relationship between scientific disciplines.the names of some scientific disciplines have been removed from the boxes. which scientific discipline belongs in the blue box? a.physics b.biology c.chemistry d.metallurgy