Problem 88a
A chemist decomposes samples of several compounds; the masses of their constituent elements are listed. Calculate the empirical formula for each compound. a. 1.245 g Ni, 5.381 g I
Problem 88b
Write a ratio showing the relationship between the molar amounts of each element for each compound. (See Appendix IIA for color codes.) (b)

Problem 88bb
A chemist decomposes samples of several compounds; the masses of their constituent elements are listed. Calculate the empirical formula for each compound. b. 2.677 g Ba, 3.115 g Br
Problem 88c
A chemist decomposes samples of several compounds; the masses of their constituent elements are listed. Calculate the empirical formula for each compound. c. 2.128 g Be, 7.557 g S, 15.107 g O
Problem 89a
Calculate the empirical formula for each stimulant based on its elemental mass percent composition.
a. nicotine (found in tobacco leaves): C 74.03%, H 8.70%, N 17.27%
b. caffeine (found in coffee beans): C 49.48%, H 5.19%, N 28.85%, O 16.48%
Problem 90a
Calculate the empirical formula for each natural flavor based on its elemental mass percent composition. a. methyl butyrate (component of apple taste and smell): C 58.80%, H 9.87%, O 31.33%
Problem 90b
Calculate the empirical formula for each natural flavor based on its elemental mass percent composition. b. vanillin (responsible for the taste and smell of vanilla): C 63.15%, H 5.30%, O 31.55%
Problem 91
The elemental mass percent composition of ibuprofen (a nonsteroidal anti-inflammatory drug [NSAID]) is 75.69% C, 8.80% H, and 15.51% O. Determine the empirical formula of ibuprofen.
Problem 92
The elemental mass percent composition of ascorbic acid (vitamin C) is 40.92% C, 4.58% H, and 54.50% O. Determine the empirical formula of ascorbic acid.
- What is the empirical formula of nitrogen chloride given that a 0.77 mg sample of nitrogen reacts with chlorine to form 6.61 mg of the chloride?
Problem 93
Problem 94
A 45.2-mg sample of phosphorus reacts with selenium to form 131.6 mg of the selenide. Determine the empirical formula of phosphorus selenide.
Problem 96a
From the given molar mass and empirical formula of several compounds, find the molecular formula of each compound. a. C4H9, 114.22 g/mol
Problem 96b
From the given molar mass and empirical formula of several compounds, find the molecular formula of each compound. b. CCl, 284.77 g/mol
Problem 97
Combustion analysis of a hydrocarbon produces 33.01 g CO2 and 13.51 g H2O. Calculate the empirical formula of the hydrocarbon.
Problem 98
Combustion analysis of naphthalene, a hydrocarbon used in mothballs, produces 8.80 g CO2 and 1.44 g H2O. Calculate the empirical formula of naphthalene.
Problem 99
The foul odor of rancid butter is due largely to butyric acid, a compound containing carbon, hydrogen, and oxygen. Combustion analysis of a 4.30-g sample of butyric acid produces 8.59 g CO2 and 3.52 g H2O. Determine the empirical formula of butyric acid.
Problem 100
Tartaric acid is the white, powdery substance that coats tart candies such as Sour Patch Kids. Combustion analysis of a 12.01-g sample of tartaric acid—which contains only carbon, hydrogen, and oxygen—produces 14.08 g CO2 and 4.32 g H2O. Determine the empirical formula of tartaric acid.
- Classify each compound as organic or inorganic: a. CaCO3 b. C4H8 c. C4H6O6 d. LiF
Problem 101
- Classify each compound as organic or inorganic: a. C8H18 b. CH3NH2 c. CaO d. FeCO3
Problem 102
Problem 104
Classify each hydrocarbon as an alkane, alkene, or alkyne. a. HC≡CH
- Write the formula based on the name, or the name based on the formula, for each hydrocarbon. a. propane b. CH3CH2CH3 c. CH3CH2CH2CH2CH3 d. octane
Problem 105
- Write the formula based on the name, or the name based on the formula, for each hydrocarbon: a. CH3CH3 b. pentane c. CH3CH2CH2CH2CH2CH3 d. heptane.
Problem 106
- Classify each organic compound as a hydrocarbon or a functionalized hydrocarbon. For functionalized hydrocarbons, identify the compound’s family. a. H3C-CH2OH
Problem 107
Problem 110
A drop of water has a volume of approximately 0.05 mL. How many water molecules does it contain? The density of water is 1.0 g/cm3.
Problem 111b
Determine the chemical formula of each compound and then use it to calculate the mass percent composition of each constituent element. a. potassium chromate b. lead(II) phosphate
Problem 111c
Determine the chemical formula of each compound and then use it to calculate the mass percent composition of each constituent element. c. sulfurous acid
Problem 111d
Determine the chemical formula of each compound and then use it to calculate the mass percent composition of each constituent element. d. cobalt(II) bromide
Problem 112
Determine the chemical formula of each compound and then use it to calculate the mass percent composition of each constituent element. c. nitrogen triiodide
Problem 113
A Freon leak in the air-conditioning system of an old car releases 25 g of CF2Cl2 per month. What mass of chlorine does this car emit into the atmosphere each year?
Problem 115
A metal (M) forms a compound with the formula MCl3. If the compound contains 65.57% Cl by mass, what is the identity of the metal?
Ch.3 - Molecules and Compounds
