Problem 59c
Calculate the formula mass for each compound. a. NO2 c. C6H12O6 b. C4H10 d. Cr(NO3)3
Problem 60a
Calculate the formula mass for each compound. a. MgBr2 b. HNO2 c. CBr4 d. Ca(NO3)2
Problem 64a
Determine the number of moles (of molecules or formula units) in each sample. a. 55.98 g CF2Cl2
Problem 64b
Determine the number of moles (of molecules or formula units) in each sample. b. 23.6 kg Fe(NO3)2
Problem 64c
Determine the number of moles (of molecules or formula units) in each sample. c. 0.1187 g C8H18
Problem 64d
Determine the number of moles (of molecules or formula units) in each sample. d. 195 kg CaO
Problem 65a
How many molecules are in each sample? a. 6.5 g H2O c. 22.1 g O2 d. 19.3 g C8H10
Problem 66
How many molecules (or formula units) are in each sample? a. 85.26 g CCl4 b. 55.93 kg NaHCO3 c. 119.78 g C4H10 d. 4.59×105 g Na3PO4
Problem 67a
Calculate the mass (in g) of each sample. a. 5.94×1020 SO3 molecules b. 2.8×1022 H2O molecules c. 1 glucose molecule (C6H12O6)
Problem 68a
Calculate the mass (in g) of each sample. a. 4.5×1025 O3 molecules
Problem 68b
Calculate the mass (in g) of each sample. b. 9.85×1019 CCl2F2 molecules c. 1 water molecule
Problem 69
A sugar crystal contains approximately 1.8×1017 sucrose (C12H22O11) molecules. What is its mass in mg?
Problem 70
A salt crystal has a mass of 0.12 mg. How many NaCl formula units does it contain?
Problem 71a
Calculate the mass percent composition of carbon in each carbon-containing compound. a. CH4 b. C2H6
Problem 71c
Calculate the mass percent composition of carbon in each carbon-containing compound. c. C2H2
Problem 71d
Calculate the mass percent composition of carbon in each carbon-containing compound. d. C2H5Cl
Problem 72a
Calculate the mass percent composition of nitrogen in each nitrogen-containing compound. a. N2O b. NO
Problem 72c
Calculate the mass percent composition of nitrogen in each nitrogen-containing compound. c. NO2
Problem 73
Most fertilizers consist of nitrogen-containing compounds such as NH3, CO(NH2)2, NH4NO3, and (NH4)2SO4. Plants use the nitrogen content in these compounds for protein synthesis. Calculate the mass percent composition of nitrogen in CO(NH2)2.
Problem 74
Iron in the earth is in the form of iron ore. Common ores include Fe2O3 (hematite), Fe3O4 (magnetite), and FeCO3 (siderite). Calculate the mass percent composition of iron for each of these iron ores. Which ore has the highest iron content?
Problem 75
Copper(II) fluoride contains 37.42% F by mass. Calculate the mass of fluorine (in g) in 55.5 g of copper(II) fluoride.
Problem 76
Silver chloride, often used in silver plating, contains 75.27% Ag by mass. Calculate the mass of silver chloride required to plate 155 mg of pure silver.
Problem 77
The iodide ion is a dietary mineral essential to good nutrition. In countries where potassium iodide is added to salt, iodine deficiency (or goiter) has been almost completely eliminated. The recommended daily allowance (RDA) for iodine is 150 mg/day. How much potassium iodide (76.45% I) should you consume if you want to meet the RDA?
Problem 81a
Determine the number of moles of hydrogen atoms in each sample. a. 0.0885 mol C4H10 b. 1.3 mol CH4
Problem 81c
Determine the number of moles of hydrogen atoms in each sample. c. 2.4 mol C6H12
Problem 82
Determine the number of moles of oxygen atoms in each sample. a. 4.88 mol H2O2 b. 2.15 mol N2O c. 0.0237 mol H2CO3 d. 24.1 mol CO2
Problem 83a
Calculate mass (in grams) of sodium in 8.5 g of each sodium containing food additive. a. NaCl (table salt) b. Na3PO4 (sodium phosphate) c. NaC7H5O2 (sodium benzoate) d. Na2C6H6O7 (sodium hydrogen citrate)
Problem 84b
Calculate the mass (in kilograms) of chlorine in 25 kg of each chlorofluorocarbon (CFC). b. CFCl3
Problem 85
How many fluorine atoms are present in 5.85 g of C2F4?
Problem 86
How many bromine atoms are present in 35.2 g of CH2Br2?
Ch.3 - Molecules and Compounds
