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- (a) Combustion analysis of 150.0 mg of 1,2,3,benzenetriol, a compound composed of carbon, hydrogen, and oxy-gen, gives 64.3 mg of H2O and 314.2 mg of CO2. What is the empirical formula of 1,2,3,benzenetriol?
Problem 107
- Assume that gasoline has the formula C8H18 and has a density of 0.703 g/mL. How many pounds of CO2 are produced from the complete combustion of 1.00 gal of gasoline?
Problem 110
- Compound X contains only carbon, hydrogen, nitrogen, and chlorine. When 1.00 g of X is dissolved in water and allowed to react with excess silver nitrate, AgNO3, all the chlorine in X reacts and 1.95 g of solid AgCl is formed. When 1.00 g of X undergoes complete combustion, 0.900 g of CO2 and 0.735 g of H2O are formed. What is the empirical formula of X?
Problem 111
- A pulverized rock sample believed to be pure calcium carbonate, CaCO3, is subjected to chemical analysis and found to contain 51.3% Ca, 7.7% C, and 41.0% O by mass. Why can't this rock sample be pure CaCO3?
Problem 112
- A certain alcoholic beverage contains only ethanol (C2H6O) and water. When a sample of this beverage undergoes com-bustion, the ethanol burns but the water simply evaporates and is collected along with the water produced by combus-tion. The combustion reaction is When a 10.00 g sample of this beverage is burned, 11.27 g of water is collected. What is the mass in grams of ethanol, and what is the mass of water in the original sample?
Problem 113
Problem 114
A mixture of FeO and Fe2O3 with a mass of 10.0 g is con-verted to 7.43 g of pure Fe metal. What are the amounts in grams of FeO and Fe2O3 in the original sample?
Problem 115
A compound of formula XCl3 reacts with aqueous AgNO3 to yield solid AgCl according to the following equation: When a solution containing 0.634 g of XCl3 was allowed to react with an excess of aqueous AgNO3, 1.68 g of solid AgCl was formed. What is the identity of the atom X?
Problem 117a
A copper wire having a mass of 2.196 g was allowed to react with an excess of sulfur. The excess sulfur was then burned, yielding SO2 gas. The mass of the copper sulfide produced was 2.748 g. (a) What is the percent composition of copper sulfide?
Problem 117b
A copper wire having a mass of 2.196 g was allowed to react with an excess of sulfur. The excess sulfur was then burned, yielding SO2 gas. The mass of the copper sulfide produced was 2.748 g. (b) What is its empirical formula?
- A mixture of XCl3 and XCl5 weighing 10.00 g contains 81.04% Cl by mass. How many grams of XCl3 and how many grams of XCl5 are present in the mixture?
Problem 119
Problem 120
Ammonium nitrate, a potential ingredient of terrorist bombs, can be made nonexplosive by addition of diammo-nium hydrogen phosphate, (NH4)2HPO4. Analysis of such a NH4NO3 - (NH4)2HPO4 mixture showed the mass percent of nitrogen to be 30.43%. What is the mass ratio of the two components in the mixture?
- Window glass is typically made by mixing soda ash (Na2CO3), limestone (CaCO3), and silica sand (SiO2) and then heating to 1500 °C to drive off CO2 from the (Na2CO3) and CaCO3. The resultant glass consists of about 12% Na2O by mass, 13% CaO by mass, and 75% SiO2 by mass. How much of each reactant would you start with to prepare 0.35 kg of glass?
Problem 121
- An unidentified metal M reacts with an unidentified halogen X to form a compound MX2. When heated, the compound decomposes by the reaction: When 1.12 g of MX2 is heated, 0.720 g of MX is obtained, along with 56.0 mL of X2 gas. Under the conditions used, 1.00 mol of the gas has a volume of 22.41 L. (a) What is the atomic weight and identity of the halogen X?
Problem 122
- Ethylene glycol, commonly used as automobile antifreeze, contains only carbon, hydrogen, and oxygen. Combustion analysis of a 23.46 mg sample yields 20.42 mg of H2O and 33.27 mg of CO2. What is the empirical formula of ethylene glycol? What is its molecular formula if it has a molecular weight of 62.0?
Problem 123
Problem 124b
(b) If the molecular weight is 326.26, what is the molecular formula?
Problem 124c
(c) Can combustion analysis be used to determine the empirical formula of a compound containing carbon, hydrogen, oxygen, and chlorine?
- Correct the error in each of the following statements: (a) The formula of ammonia is NH3 (b) Molecules of potassium chloride have the formula KCl. (c) Cl-is a cation. (d) CH4 is a polyatomic ion
Problem 137
- When solid mercury(I) carbonate, Hg2CO3, is added to nitric acid, HNO3, a reaction occurs to give mercury(II) nitrate, Hg1NO322, water, and two gases A and B: Hg2CO31s2 + HNO31aq2¡ Hg1NO3221aq2 + H2O1l 2 + A1g2 + B1g2 (e) Write a balanced equation for the reaction of mercury(I) carbonate with nitric acid.
Problem 138
- A mixture of CuO and Cu2O with a mass of 10.50 g is reduced to give 8.66 g of pure Cu metal. What are the amounts in grams of CuO and Cu2O in the original mixture?
Problem 142
- Write formulas for the following binary compounds: (a) Potassium chloride (b) Tin(II) bromide (c) Calcium oxide (d) Barium chloride (e) Aluminum hydride
Problem 148
- Write formulas for compounds of calcium with each of the following: a) Chlorine b) Oxygen c) Sulfur
Problem 156
- Write formulas for compounds of rubidium with each of the following: (a) Bromine (b) Nitrogen (c) Selenium
Problem 157
- Give the formulas and charges of the following ions: (a) Sulfite ion (b) Phosphate ion (c) Zirconium(IV) ion (d) Chromate ion (e) Acetate ion (f) Thiosulfate ion
Problem 158
- Name the following binary molecular compounds: (a) CCl4 (b) ClO2 (c) N2O (d) N2O3
Problem 160
- Give systematic names for the following compounds: (a) NCl3 (b) P4O6 (c) S2F2
Problem 161
- Name the following binary compounds of nitrogen and oxygen: (a) NO (b) N2O (c) NO2 (d) N2O4 (e) N2O5
Problem 162
- Fill in the missing information to give formulas for the fol-lowing compounds: (a) Na?SO4 (b) Ba?(PO4)? (c) Ga?(SO4)?
Problem 164
- Write formulas for each of the following compounds: (a) Sodium peroxide (b) Aluminum bromide (c) Chromium(III) sulfate
Problem 165
- The mass percent of an element in a compound is the mass of the element (total mass of the element's atoms in the com-pound) divided by the mass of the compound (total mass of all atoms in the compound) times 100%. What is the mass per-cent of each element in acetaminophen? (See Problem 2.170.)
Problem 171