Using the reaction, calculate the moles of hydrogen gas produced from the reaction of 4.5 moles of zinc: Zn+2HCl -> ZnCl2+H2

A. 1.0 mols H2
B. 2.0 mols H2
C. 4.0 mols H2
D. 4.5 mols H2

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

Is 9 correct? and can someone me with 10? it’s due tomorrow, you

Who discovered a pattern to the elements in 1869?