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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
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,b
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 95
From the given empirical formula and molar mass, find the molecular formula of each compound. a. C6H7N, 186.24 g/mol
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 96c
From the given molar mass and empirical formula of several compounds, find the molecular formula of each compound. c. C3H2N, 312.29 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.
Problem 101
Sulfuric acid is a component of acid rain formed when gaseous sulfur dioxide pollutant reacts with gaseous oxygen and liquid water to form aqueous sulfuric acid. Write the balanced chemical equation this reaction. (Note: this is a simplified representation of this reaction.)
Problem 102
Nitric acid is a component of acid rain that forms when gaseous nitrogen dioxide pollutant reacts with gaseous oxygen and liquid water to form aqueous nitric acid. Write the balanced chemical equation for this reaction. (Note: this is a simplified representation of this reaction.)
- In a popular classroom demonstration, solid sodium is added to liquid water and reacts to produce hydrogen gas and aqueous sodium hydroxide. What is the balanced chemical equation for this reaction?
Problem 103
Problem 104
When iron rusts, solid iron reacts with gaseous oxygen to form solid iron(III) oxide. Write the balanced chemical equation for this reaction.
Problem 105
Write the balanced chemical equation for the fermentation of sucrose (C12H22O11) by yeasts in which the aqueous sugar reacts with water to form aqueous ethanol (C2H5OH) and carbon dioxide gas.
- Write the balanced equation for the photosynthesis reaction in which gaseous carbon dioxide and liquid water react in the presence of chlorophyll to produce aqueous glucose (C6H12O6) and oxygen gas.
Problem 106
Problem 107a
Write the balanced chemical equation for each reaction. a. Solid lead(II) sulfide reacts with aqueous hydrobromic acid to form solid lead(II) bromide and dihydrogen monosulfide gas.
Problem 107b
Write the balanced chemical equation for each reaction. b. Gaseous carbon monoxide reacts with hydrogen gas to form gaseous methane (CH4) and liquid water.
Problem 107c
Write the balanced chemical equation for each reaction. c. Aqueous hydrochloric acid reacts with solid manganese(IV) oxide to form aqueous manganese(II) chloride, liquid water, and chlorine gas.
Problem 107d
Write the balanced chemical equation for each reaction. d. Liquid pentane (C5H12) reacts with gaseous oxygen to form carbon dioxide and liquid water.
Problem 108a
Write the balanced chemical equation for each reaction. a. Solid copper reacts with solid sulfur to form solid copper(I) sulfide.
Problem 108b
Write the balanced chemical equation for each reaction. b. Solid iron(III) oxide reacts with hydrogen gas to form solid iron and liquid water.