Part A Determine the empirical and molecular formulas of each of the following substances. Caffeine, a stimulant found in coffee, contains 49.5% C, 5.15% H, 28.9% N, and 16.5 % O by mass and has a molar mass of 195 g/mol. Express your answers as chemical formulas separated by a comma.

Part A Determine the empirical and molecular formulas of each of the following substances. Caffeine, a stimulant found in coffee, contains 49.5% C, 5.15% H, 28.9% N, and 16.5 % O by mass and has a molar mass of 195 g/mol. Express your answers as chemical formulas separated by a comma.

Introductory Chemistry: A Foundation

9th Edition

ISBN:9781337399425

Author:Steven S. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Donald J. DeCoste

Chapter9: Chemical Quantities

Section: Chapter Questions

Problem 6CR

See similar textbooks

Similar questions

hat is the difference between the empirical and molecular for mulas of a compound? Can they ever be the same? Explain.
The active ingredient in Pepto-BismoÂ® (an over- the-counter remedy for an upset stomach) is bismuth sub-salicylate, C7H5BiO4. Analysis of a 1.7500-g sample of Pepto-Bismol yields 346 mg of bismuth. What percent by mass is bismuth subsalicylate in the sample? (Assume that there are no other bismuth-containing compounds in Pepto-Bismol.)
When analyzed, an unknown compound gave these experimental results: C, 54.0%; h, 6.00%; and O, 40.0%. Four different students used these values to calculate the empirical formulas shown here. Which answer is correct? Why did some students not get the correct answer? (a) C4H5O2 (b) C5H7O3 (c) C7H10O4 (d) C9H12O5
Cacodyl, a compound containing arsenic, was reported in 1842 by the German chemist Robert Wilhelm Bunsen. It has an almost intolerable garlic-like odor. Its molar mass is 210 g/mol, and it is 22.88% C, 5.76% H, and 71.36% As. Determine its empirical and molecular formulas.
Calculate, to two decimal places, the formula mass of each of the following substances. Obtain the needed atomic masses from the inside front cover of the text. a. C20H30O (vitamin A) b. C14H9Cl5 (DDT, formerly used as an insecticide) c. C8H10N4O2 (caffeine, a central nervous system stimulant) d. Ca(NO3)2 (calcium nitrate, gives fireworks their red color)
Tetrodotoxin is a toxic chemical found in fugu pufferfish, a popular but rare delicacy in Japan. This compound has an LD50 (the amount of substance that is lethal to 50.% of a population sample) of 10.g per kg of body mass. Tetrodotoxin is 41.38% carbon by mass, 13.16% nitrogen by mass, and 5.37% hydrogen by mass, with the remaining amount consisting of oxygen. What is the empirical formula of tetrodotoxin? If three molecules of tetrodotoxin have a mass of 1.59 1021 g, what is the molecular formula of tetrodotoxin? What number of molecules of tetrodotoxin would be the LD50 dosage for a person weighing 165 lb?
Calculate, to two decimal places, the formula mass of each of the following substances. Obtain the needed atomic masses from the inside front cover of the text. a. C12H22O11 (sucrose, table sugar) b. C7H16 (heptane, a component of gasoline) c. C7H5NO3S (saccharin, an artificial sweetener) d. (NH4)2SO4 (ammonium sulfate, a lawn fertilizer)
3.105 Nitric acid is often sold and transported as a concentrated 16 M aqueous solution. How many gallons of such a solution would be needed to contain the roughly 2.1109 pounds of HNO3 produced annually in the United States?
itamin B12 , cyancobalamin, is essential for human nutrition. Its molecular formula is C63H88CoN14O14P . A lack of this vita min in the diet can lead to anemia. Cyanocohalamin is the form of the vitamin found in vitamin supplements. l type='a'> What is the molar mass of cyanocobalamin to two decimal places? How many moles of cyanocohalamin molecules are present in 250 mg of cyanocobalamin? What is the mass of 0.60 mole of cyanocobalamin? How many atoms of hydrogen are in 1 .0 mole of cyanocobalamin? What is the mass of 1.0107 molecules of cyanocobalamin? What is the mass (in grams) of one molecule of cyanocobalamin?
3.98 The characteristic odor of decaying flesh is due to the presence of various nitrogen-containing compounds. One such compound, called putrescine, was analyzed and found to contain 54.49% carbon, 13.72% hydrogen, and 31.78% nitrogen by mass. If the molar mass of putrescine is known to be between 85 and 105, what is its molecular formula?
What is the molarity of each ion present in aqueous solutions of the following compounds prepared by dissolving 28.0 g of each compound in water to make 785 mL of solution? (a) potassium oxide (b) sodium hydrogen carbonate (c) scandium(III) iodite (d) magnesium phosphate
The active ingredient in some antiperspirants is aluminum chlorohydrate, Al2(OH)5Cl. Analysis of a 2.000-g sample of antiperspirant yields 0.334 g of aluminum. What percent (by mass) of aluminum chlorohydrate is present in the antiperspirant? (Assume that there are no other compounds containing aluminum in the antiperspirant.)