The equilibrium constant KP for the reaction is 1.05 at 250°C. The reaction starts with a mixture of PCl5, PCl3, and Cl2 at pressures 0.177 atm, 0.223 atm, and 0.111 atm, respectively, at...
Ammonium carbamate, NH4CO2NH2, decomposes as follows: Starting with only the solid, it is found that at 40°C the total gas pressure (NH3 and CO2) is 0.363 atm. Calculate the equilibrium constant...
A 2.50-mole quantity of NOCl was initially in a 1.50-L reaction chamber at 400°C. After equilibrium was established, it was found that 28.0 percent of the NOCl had dissociated: Calculate the...
For the synthesis of ammonia the equilibrium constant Kc at 375°C is 1.2. Starting with [H2]0 = 0.76 M, [N2]0 = 0.60 M, and [NH3]0 = 0.48 M, which gases will have increased in concentration and...
For the reaction at 700°C, Kc = 0.534. Calculate the number of moles of H2 that are present at equilibrium if a mixture of 0.300 mole of CO and 0.300 mole of H2O is heated to 700°C in a...
At 1000 K, a sample of pure NO2 gas decomposes: The equilibrium constant KP is 158. Analysis shows that the partial pressure of O2 is 0.25 atm at equilibrium. Calculate the pressure of NO and NO2 in...
The equilibrium constant Kc for the reaction is 2.18 Ã 106 at 730°C. Starting with 3.20 moles of HBr in a 12.0-L reaction vessel, calculate the concentrations of H2, Br2, and HBr at...
Consider the equilibrium What would be the effect on the position of equilibrium of (a) Increasing the total pressure on the system by decreasing its volume; (b) Adding gaseous I2 to the reaction...
A mixture of 0.47 mole of H2 and 3.59 moles of HCl is heated to 2800°C. Calculate the equilibrium partial pressures of H2, Cl2, and HCl if the total pressure is 2.00 atm. For the reaction KP is...
A solution contains a weak monoprotic acid HA and its sodium salt NaA both at 0.1 M concentration. Show that [OH2] = Kw/Ka.
Use the data in Table 15.3 to calculate the equilibrium constant for the following reaction: HCOOH(aq) + OH-(aq) HCOO-(aq) + H2O(l)
(a) Use VSEPR to predict the geometry of the hydronium ion, H3O1. (b) The O atom in H2O has two lone pairs and in principle can accept two H1 ions. Explain why the species H4O2+ does not exist. What...
A solution of formic acid (HCOOH) has a pH of 2.53. How many grams of formic acid are there in 100.0 mL of the solution?
A solution of methylamine (CH3NH2) has a pH of 10.64. How many grams of methylamine are there in 100.0 mL of the solution?
About half of the hydrochloric acid produced annually in the United States (3.0 billion pounds) is used in metal pickling. This process involves the removal of metal oxide layers from metal surfaces...
A 1.294-g sample of a metal carbonate (MCO3) is reacted with 500 mL of a 0.100 M HCl solution. The excess HCl acid is then neutralized by 32.80 mL of 0.588 M NaOH. Identify M.
A solution is made by dissolving 18.4 g of HCl in 662 mL of water. Calculate the pH of the solution. (Assume that the volume remains constant.)
(1) Which of the following diagrams represents a solution of a weak diprotic acid? (2) Which diagrams represent chemically implausible situations?
(a) Calculate the percent ionization of a 0.20 M solution of the monoprotic acetylsalicylic acid (aspirin) for which Ka 5 3.0 3 10-4. (b) The pH of gastric juice in the stomach of a certain...
The pH of a 0.30 M solution of a weak base is 10.66. What is the Kb of the base?
Predict whether the following solutions are acidic, basic, or nearly neutral: (a) NaBr, (b) K2SO3, (c) NH4NO2, (d) Cr(NO3)3.
Arrange the oxides in each of the following groups in order of increasing basicity: (a) K2O, Al2O3, BaO, (b) CrO3, CrO, Cr2O3.
Al(OH)3 is an insoluble compound. It dissolves in excess NaOH in solution. Write a balanced ionic equation for this reaction. What type of reaction is this?
All Brnsted acids are Lewis acids, but the reverse is not true. Give two examples of Lewis acids that are not Brnsted acids.
A typical reaction between an antacid and the hydrochloric acid in gastric juice is NaHCO3(s) + HCl(aq) NaCl(aq) + H2O(l) + CO2(g) Calculate the volume (in L) of CO2 generated from 0.350 g of NaHCO3...
A student is asked to prepare a buffer solution at pH = 8.60, using one of the following weak acids: HA (Ka = 2.7 10-3), HB (Ka = 4.4 10-6), HC (Ka = 2.6 10-9). Which acid should she choose? Why?
A5.00-g quantity of a diprotic acid was dissolved in water and made up to exactly 250 mL. Calculate the molar mass of the acid if 25.0 mL of this solution required 11.1 mL of 1.00 M KOH for...
A solution is made by mixing 5.00 102 mL of 0.167 M NaOH with 5.00 102 mL of 0.100 M CH3COOH. Calculate the equilibrium concentrations of H1, CH3COOH, CH3COO-, OH2, and Na+.
A 10.0-mL solution of 0.300 M NH3 is titrated with a 0.100 M HCl solution. Calculate the pH after the following additions of the HCl solution: (a) 0.0 mL, (b) 10.0 mL, (c) 20.0 mL, (d) 30.0 mL, (e)...
An electric power station annually burns 3.1 107 kg of coal containing 2.4 percent sulfur by mass. Calculate the volume of SO2 emitted at STP.
Assume that the formation of nitrogen dioxide: 2NO(g) + O2(g) 2NO2(g) is an elementary reaction. (a) Write the rate law for this reaction. (b) A sample of air at a certain temperature is...
A volume of 5.0 L of polluted air at 18.0C and 747 mmHg is passed through lime water [an aqueous suspension of Ca(OH)2], so that all the carbon dioxide present is precipitated as CaCO3. If the mass...
As stated in the chapter, carbon monoxide has a much higher affinity for hemoglobin than oxygen does. (a) Write the equilibrium constant expression (Kc) for the following process: where HbO2 and HbCO...
Although the hydroxyl radical (OH) is present only in a trace amount in the troposphere, it plays a central role in its chemistry because it is a strong oxidizing agent and can react with many...
A person was found dead of carbon monoxide poisoning in a well-insulated cabin. Investigation showed that he had used a blackened bucket to heat water on a butane burner. The burner was found to...
As stated in the chapter, about 50 million tons of sulfur dioxide are released into the atmosphere every year. (a) If 20 percent of the SO2 is eventually converted to H2SO4, calculate the number of...
A student placed 1 g of each of three compounds A, B, and C in a container and found that after 1 week no change had occurred. Offer some possible explanations for the fact that no reactions took...
Ammonium nitrate (NH4NO3) dissolves spontaneously and endothermically in water. What can you deduce about the sign of S for the solution process?
(a) Trouton's rule states that the ratio of the molar heat of vaporization of a liquid (Hvap) to its boiling point in kelvins is approximately 90 J/K ? mol. Use the following data to show that this...
(a) Over the years there have been numerous claims about "perpetual motion machines," machines that will produce useful work with no input of energy. Explain why the first law of thermodynamics...
Active transport is the process in which a substance is transferred from a region of lower concentration to one of higher concentration. This is a non spontaneous process and must be coupled to a...
A rubber band is stretched vertically by attaching a weight to one end and holding the other end by hand. On heating the rubber band with a hot-air blower, it is observed to shrink slightly in...
A student looked up the Gf, Hf, and S values for CO2 in Appendix 3. Plugging these values into Equation (18.10), he found that Gf ? Hf TS at 298 K. What is wrong with his approach?
At 0 K, the entropy of carbon monoxide crystal is not zero but has a value of 4.2 J/K ? mol, called the residual entropy. According to the third law of thermodynamics, this means that the crystal...
An acidified solution was electrolyzed using copper electrodes. A constant current of 1.18 A caused the anode to lose 0.584 g after 1.52 3 103 s. (a) What is the gas produced at the cathode and what...
An aqueous solution of a platinum salt is electrolyzed at a current of 2.50 A for 2.00 h. As a result, 9.09 g of metallic Pt are formed at the cathode. Calculate the charge on the Pt ions in this...
A silver rod and a SHE are dipped into a saturated aqueous solution of silver oxalate, Ag2C2O4, at 25C. The measured potential difference between the rod and the SHE is 0.589 V, the rod being...
A certain mine produces 2.0 108 kg of copper from chalcopyrite (CuFeS2) each year. The ore contains only 0.80 percent Cu by mass. (a) If the density of the ore is 2.8 g/cm3, calculate the volume (in...
Aluminum forms the complex ions AlCl4- and AlF63-. Describe the shapes of these ions. AlCl63- does not form. Why?
In basic solution, aluminum metal is a strong reducing agent and is oxidized to AlO2-. Give balanced equations for the reaction of Al in basic solution with the following: (a) NaNO3, to give ammonia;...
After heating, a metal surface (such as that of a cooking pan or skillet) develops a color pattern like an oil slick on water. Explain.
As stated in the chapter, potassium superoxide (KO2) is a useful source of oxygen employed in breathing equipment. Calculate the pressure at which oxygen gas stored at 20C would have the same density...
A sample of 10.00 g of sodium reacts with oxygen to form 13.83 g of sodium oxide (Na2O) and sodium peroxide (Na2O2). Calculate the percent composition of the mixture. Discuss.
As mentioned in Chapter 3, ammonium nitrate is the most important nitrogen-containing fertilizer in the world. Given only air and water as starting materials and any equipment and catalyst at your...
As we saw in Section 20.2, the reduction of iron oxides is accomplished by using carbon monoxide as a reducing agent. Starting with coke in a blast furnace, the following equilibrium plays a key role...
Assuming ideal behavior, calculate the density of gaseous HF at its normal boiling point (19.5C). The experimentally measured density under the same conditions is 3.10 g/L. Account for the...
A piece of red-hot magnesium ribbon will continue to burn in an atmosphere of CO2 even though CO2 does not support combustion. Explain.
Aqueous copper(II) sulfate solution is blue. When aqueous potassium fluoride is added to the CuSO4 solution, a green precipitate is formed. If aqueous potassium chloride is added instead, a...
(a) Which of the following compounds has the greatest ionic character? PCl5, SiCl4, CCl4, BCl3 (b) Which of the following ions has the smallest ionic radius? F-, C4-, N3-, O2- (c) Which of the...
A solution made by dissolving 0.875 g of Co(NH3)4Cl3 in 25.0 g of water freezes at 20.56C. Calculate the number of moles of ions produced when 1 mole of Co(NH3)4Cl3 is dissolved in water and suggest...
A student has prepared a cobalt complex that has one of the following three structures: [Co(NH3)6]Cl3, [Co(NH3)5Cl]Cl2, or [Co(NH3)4Cl2]Cl. Explain how the student would distinguish between these...
A student in 1895 prepared three coordination compounds containing chromium, with the following properties: CI Ions in Solution per Formula Unit Formula Color (a) CrCl 6H2 Violet (b) CrCl, 6H0 Light...
Aqueous solutions of CoCl2 are generally either light pink or blue. Low concentrations and low temperatures favor the pink form while high concentrations and high temperatures favor the blue form....
(a) The free Cu(I) ion is unstable in solution and has a tendency to disproportionate: Use the information in Table 19.1 to calculate the equilibrium constant for the reaction. (b) Based on your...
The radius of a uranium-235 nucleus is about 7.0 10-3 pm. Calculate the density of the nucleus in g/cm3. (Assume the atomic mass is 235 amu.)
Calculate the nuclear binding energy (in J) and the binding energy per nucleon of the following isotopes: (a) 73Li (7.01600 amu) and (b) 3517Cl(34.95952 amu).
(a) What is the activity, in millicuries, of a 0.500-g sample of 23793Np? (This isotope decays by -particle emission and has a half-life of 2.20 106 yr.) (b) Write a balanced nuclear equation for...
After the Chernobyl accident, people living close to the nuclear reactor site were urged to take large amounts of potassium iodide as a safety precaution. What is the chemical basis for this action?
Astatine, the last member of Group 7A, can be prepared by bombarding bismuth-209 with particles. (a) Write an equation for the reaction. (b) Represent the equation in the abbreviated form, as...
Both barium (Ba) and radium (Ra) are members of Group 2A and are expected to exhibit similar chemical properties. However, Ra is not found in barium ores. Instead, it is found in uranium ores....
Nuclear waste disposal is one of the major concerns of the nuclear industry. In choosing a safe and stable environment to store nuclear wastes, consideration must be given to the heat released during...
As a result of being exposed to the radiation released during the Chernobyl nuclear accident, the dose of iodine-131 in a person's body is 7.4 mCi (1 mCi = 1 10-3 Ci). Use the relationship rate = N...
Americium-241 is used in smoke detectors because it has a long half-life (458 yr) and its emitted α particles are energetic enough to ionize air molecules. Given the schematic diagram...
A radioactive isotope of copper decays as follows: Starting with 84.0 g of 64Cu, calculate the quantity of 64Zn produced after 18.4 h. 6Cu 64, 64Zn + -iB = 12.8 h
The quantity of a radioactive material is often measured by its activity (measured in curies or millicuries) rather than by its mass. In a brain scan procedure, a 70-kg patient is injected with 20.0...
Alpha particles produced from radioactive decays eventually pick up electrons from the surroundings to form helium atoms. Calculate the volume (mL) of He collected at STP when 1.00 g of pure 226Ra is...
An electron and a positron are accelerated to nearly the speed of light before colliding in a particle accelerator. The ensuing collision produces an exotic particle having a mass many times that of...
Acetylene is an unstable compound. It has a tendency to form benzene as follows: 3C2H2(g) C6H6(l) Calculate the standard enthalpy change in kilojoules per mole for this reaction at 25C.
Draw structures for molecules with the following formulas: (a) CH4O. (b) C2H6O. (c) C3H6-2. (d) C3H8O.
A compound has the empirical formula C5H12O. Upon controlled oxidation, it is converted into a compound of empirical formula C5H10O, which behaves as a ketone. Draw possible structures for the...
Predict the product or products of each of the following reactions: (a) CH3CH2OH + HCOOH (b) HOC¡C-CH3 + H2 (c) C2H5
An organic compound is found to contain 37.5 percent carbon, 3.2 percent hydrogen, and 59.3 percent fluorine by mass. The following pressure and volume data were obtained for 1.00 g of this substance...
Name the classes to which the following compounds belong: (a) C4H9OH (b) CH3OC2H5 (c) C2H5CHO (d) C6H5COOH (e) CH3NH2
Ethanol, C2H5OH, and dimethyl ether, CH3OCH3, are structural isomers. Compare their melting points, boiling points, and solubilities in water.
Amines are Brnsted bases. The unpleasant smell of fish is due to the presence of certain amines. Explain why cooks often add lemon juice to suppress the odor of fish (in addition to enhancing the...
"Dark meat" and "white meat" are one's choices when eating a turkey. Explain what causes the meat to assume different colors. (The more active muscles in a turkey have a higher rate of metabolism and...
Give the hybridization of the central atom of each of the following species, and tell whether the bond arrangement around it is linear, trigonal planar, or tetrahedral: a. NH3 b. BH3 c. -CH3 d. CH3...
Draw the condensed structure of a compound that contains only carbon and hydrogen atoms and that has a. Three sp3 hybridized carbons. b. One sp3 hybridized carbon and two sp2 hybridized carbons. c....
The following compound has two isomers: ClCH==CHCl One isomer has a dipole moment of 0 D, and the other has a dipole moment of 2.95 D. Propose structures for the two isomers that are consistent with...
Which of the following can be used to verify that carbon is tetrahedral? a. Methyl bromide does not have constitutional isomers. b. Tetrachloromethane does not have a dipole moment. c. Dibromomethane...
a. Using the bond dissociation energies in Table 3.1, calculate the H for the addition of HCl to ethene. b. Calculate the H for the addition of H2 to ethene. c. Are the reactions exothermic or...
Identify the electrophile and the nucleophile in each of the following reaction steps. Then draw curved arrows to illustrate the bond-making and bond-breaking processes. a. b. c. CH3CHCH, - +...
a. What product is obtained from the reaction of HCl with 1-butene? With 2-butene? b. Which of the two reactions has the greater free energy of activation? c. Which of the two alkenes reacts more...
a. What products would be obtained from the addition of Br2 to cyclohexene if the solvent were instead of b. Propose a mechanism for the reaction.
Explain how R and S are related to and (+) (-).
Give the products of the following reactions. If the products can exist as stereoisomers, show which stereoisomers are obtained. a. Cis-2-pentene + Br2JCH2CI2 b. Trans.2-pcn(cnc + Br2CH2C1 c....
a. Draw all possible stereoisomers for the following compound b. Which isomers are optically inactive (will not rotate plane-polarized light)? HOCH,CH-CH CHCH OH OH OH OH
A student wanted to know whether the greater proximity of the nucleophile to the C-2 carbon in the transition state was what caused the 1,2-addition product to be formed faster when 1,3-butadiene...
Give the product of the reaction of methyl bromide with each of the following nucleophiles: a. HO- b. -NH2 c. H2S d. HS- e. CH3O- f. CH3NH2
Propose a mechanism for each of the following reactions: a. b. CH3 CH-Br CH H20 CH H20 CH3 H3C CHCH CH3 CH3