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Problem 102
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 103
From the given empirical formula and molar mass, find the molecular formula of each compound. a. C6H7N, 186.24 g/mol
Problem 104a
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 104b
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 104c
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 105
Combustion analysis of a hydrocarbon produces 33.01 g CO2 and 13.51 g H2O. Calculate the empirical formula of the hydrocarbon.
Problem 106
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 107
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 108
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 109
Problem 111
Classify each hydrocarbon as an alkane, alkene, or alkyne. a. H2C=CH−CH3 b. H3C−CH2−CH3 c. HC≡C−CH3 d. H3C−CH2−CH2−CH3
Problem 112
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 113
- 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 114
- Classify each organic compound as a hydrocarbon or a functionalized hydrocarbon. For functionalized hydrocarbons, identify the compound’s family. a. H3C-CH2OH
Problem 115
Problem 117
How many molecules of ethanol (C2H5OH) (the alcohol in alcoholic beverages) are present in 145 mL of ethanol? The density of ethanol is 0.789 g/cm3.
Problem 118
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 121b
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 121c
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 122
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 123
A Freon leak in the air-conditioning system of an old car releases 38.0 g of CF2Cl2 per month. What mass of chlorine does this car emit into the atmosphere each year?
Problem 123d
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 125
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?
Problem 126
A metal (M) forms an oxide with the formula M2O. If the oxide contains 16.99% O by mass, what is the identity of the metal?
- Estradiol is a female sexual hormone that is responsible for the maturation and maintenance of the female reproductive system. Elemental analysis of estradiol gives the following mass percent composition: C 79.37%, H 8.88%, O 11.75%. The molar mass of estradiol is 272.37 g/mol. Find the molecular formula of estradiol.
Problem 127
Problem 128
Fructose is a common sugar found in fruit. Elemental analysis of fructose gives the following mass percent composition: C 40.00%, H 6.72%, O 53.28%. The molar mass of fructose is 180.16 g/mol. Find the molecular formula of fructose.
Problem 129
Combustion analysis of a 13.42-g sample of equilin (which contains only carbon, hydrogen, and oxygen) produces 39.61 g CO2 and 9.01 g H2O. The molar mass of equilin is 268.34 g/mol. Find its molecular formula.
Problem 130
Estrone, which contains only carbon, hydrogen, and oxygen, is a female sexual hormone in the urine of pregnant women. Combustion analysis of a 1.893-g sample of estrone produces 5.545 g of CO2 and 1.388 g H2O. The molar mass of estrone is 270.36 g/mol. Find its molecular formula.
Problem 131
Epsom salts is a hydrated ionic compound with the following formula: MgSO4 • x H2O. A 4.93-g sample of Epsom salts is heated to drive off the water of hydration. The mass of the sample after complete dehydration is 2.41 g. Find the number of waters of hydration (x) in Epsom salts.
Problem 132
A hydrate of copper(II) chloride has the following formula: CuCl2 • x H2O. The water in a 3.41-g sample of the hydrate is driven off by heating. The remaining sample has a mass of 2.69 g. Find the number of waters of hydration (x) in the hydrate.