The following questions in complete sentences. - COMPARE: What are the differences between physical change and chemical change?
- DESCRIBE: What happens to the particles of a substance as it changes from a solid to a liquid to a gas?
INFER: Why does evaporation require that heat energy be added to a substance?
RELATE: What is the relationship between the mass and the volume of an object?
ANALYZE: Is tearing paper a physical change or a chemical change?

Write two balanced equations 1. dissolving of solid sodium hydroxide in water 2. the reaction of sodium hydroxide solution with hydrochloric acid

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

Which fact represents evidence for the big bang theory?