Question: Calculate the new molarity if each of

> Distinguish between the roles of an internal and an external auditor. Cite at least two examples of auditing procedures that might reasonably be expected of an internal auditor but not an external auditor. Which type of auditor would you rather be? Why?

> What do we mean when we say that “like dissolves like”? Do two molecules have to be identical to be able to form a solution in one another?

> Calculate the pH corresponding to each of the hydroxide ion concentrations given below, and indicate whether each solution is acidic, basic, or neutral. a. [OH] = 1.4 * 10-6 M b. [OH] = 9.35 * 10-9 M c. [OH] = 2.21 * 10-1 M d. [OH] = 7.98 * 10-12

> Calculate the pH of each of the solutions indicated below. Tell whether the solution is acidic, basic, or neutral. a. [H+] = 1.49 * 10-3 M b. [OH-] = 6.54 * 10-4 M c. [H+] = 9.81 * 10-9 M d. [OH-] = 7.45 * 10-10 M

> Which of the following bases have relatively strong conjugate acids? a. F- b. Cl- c. HSO4- d. NO3-

> Many metal ions form insoluble sulfide compounds when a solution of the metal ion is treated with hydrogen sulfide gas. For example, nickel(II) precipitates nearly quantitatively as NiS when H2S gas is bubbled through a nickel ion solution. How many mill

> Calculate [H+] in each of the following solutions, and indicate whether the solution is acidic, basic, or neutral. a. [OH-] = 4.22 * 10-3 M b. [OH-] = 1.01 * 10-13 M c. [OH-] = 3.05 * 10-7 M d. [OH-] = 6.02 * 10-6 M

> Calculate the mass of AgCl formed, and the concentration of silver ion remaining in solution, when 10.0 g of solid AgNO3 is added to 50. mL of 1.0 * 10-2 M NaCl solution. Assume there is no volume change upon addition of the solid.

> Under what circumstances can we compare the solubilities of two salts by directly comparing the values of their solubility products?

> Suppose 50.0 mL of 0.250 M CoCl2 solution is added to 25.0 mL of 0.350 M NiCl2 solution. Calculate the concentration, in moles per liter, of each of the ions present after mixing. Assume that the volumes are additive.

> Explain the difference in meaning between the following two solutions: “50. g of NaCl dissolved in 1.0 L of water” and “50. g of NaCl dissolved in enough water to make 1.0 L of solution.” For which solution can the molarity be calculated directly (using

> How does equilibrium represent the balancing of opposing processes? Give an example of an “equilibrium” encountered in everyday life, showing how the processes involved oppose each other.

> A mixture is prepared by mixing 50.0 g of ethanol, 50.0 g of water, and 5.0 g of sugar. What is the mass percent of each component in the mixture? How many grams of the mixture should one take in order to have 1.5 g of sugar? How many grams of the mixtur

> The following are representations of acid–base reactions: a. Label each of the species in both equations as an acid or base, and explain. b. For those species that are acids, which labels apply: Arrhenius acid, Brønsted-

> What volume of 0.151 N NaOH is required to neutralize 24.2 mL of 0.125 N H2SO4? What volume of 0.151 N NaOH is required to neutralize 24.2 mL of 0.125 M H2SO4?

> What volume of 0.104 N H2SO4 is required to neutralize 15.2 mL of 0.152 N NaOH? What volume of 0.104 M H2SO4 is required to neutralize 15.2 mL of 0.152 M NaOH? H2SO4(aq) + 2NaOH(aq) / Na2SO4(aq) + 2H2O(l)

> Calcium sulfate, CaSO4, is only soluble in water to the extent of approximately 2.05 g/L at 25 °C. Calculate Ksp for calcium sulfate at 25°C.

> A solution of the sparingly soluble base Ca(OH)2 is prepared in a volumetric flask by dissolving 5.21 mg of Ca(OH)2 to a total volume of 1000. mL. Calculate the molarity and normality of the solution.

> The solubility product constant, Ksp, for calcium carbonate at room temperature is approximately 3.0 * 10-9. Calculate the solubility of CaCO3 in grams per liter under these conditions.

> Most hydroxides are not very soluble in water. For example, Ksp for nickel(II) hydroxide, Ni(OH)2, is 2.0 * 10-15 at 25 °C. How many grams of nickel(II) hydroxide dissolve per liter at 25 °C?

> Ksp for copper(II) hydroxide, Cu(OH)2, has a value 2.2 * 10-20 at 25 °C. Calculate the solubility of copper(II) hydroxide in mol/L and g/L at 25 °C.

> For each of the following solutions, the mass of solute taken is indicated, along with the total volume of solution prepared. Calculate the normality of each solution. a. 0.113 g NaOH; 10.2 mL b. 12.5 mg Ca(OH)2; 100. mL c. 12.4 g H2SO4; 155 mL

> The “Chemistry in Focus” segment Green Chemistry discusses the use of gaseous carbon dioxide in place of CFCs and of liquid carbon dioxide in place of the dry-cleaning chemical PERC. Would you expect carbon dioxide to be very soluble in water? Explain yo

> Why does the amount of excess solid solute present in a solution not affect the amount of solute that ultimately dissolves in a given amount of solvent?

> Explain how the dissolving of an ionic solute in water represents an equilibrium process.

> Explain why the equivalent weight of H2SO4 is half the molar mass of this substance. How many hydrogen ions does each H2SO4 molecule produce when reacting with an excess of OH- ions?

> Suppose a reaction has the equilibrium constant K = 1.3 * 108. What does the magnitude of this constant tell you about the relative concentrations of products and reactants that will be present once equilibrium is reached? Is this reaction likely to be a

> Consider the exothermic reaction CO(g) + 2H2(g) ⇌ CH3OH(l) Predict three changes that could be made to the system that would decrease the yield of product over that produced by a system in which no change was made.

> What volume of 0.101 M HNO3 is required to neutralize each of the following solutions? a. 12.7 mL of 0.501 M NaOH b. 24.9 mL of 0.00491 M Ba(OH)2 c. 49.1 mL of 0.103 M NH3 d. 1.21 L of 0.102 M KOH

> What volume of 1.00 M NaOH is required to neutralize each of the following solutions? a. 25.0 mL of 0.154 M acetic acid, HC2H3O2 b. 35.0 mL of 0.102 M hydrofluoric acid, HF c. 10.0 mL of 0.143 M phosphoric acid, H3PO4 d. 35.0 mL of 0.220 M sulfuric a

> Despite HCl’s being a strong acid, the pH of 1.00 * 10-7 M HCl is not exactly 7.00. Can you suggest a reason why?

> A sample of sodium hydrogen carbonate solid weighing 0.1015 g requires 47.21 mL of a hydrochloric acid solution to react completely. HCl(aq) + NaHCO3(s) / NaCl(aq) + H2O(l) + CO2(g) Calculate the molarity of the hydrochloric acid solution.

> Strong bases are bases that completely ionize in water to produce hydroxide ion, OH-. The strong bases include the hydroxides of the Group 1 elements. For example, if 1.0 mole of NaOH is dissolved per liter, the concentration of OH- ion is 1.0 M. Calcula

> The “Chemistry in Focus” segment Water, Water Everywhere, But . . . discusses the desalinization of ocean water. Explain why many salts are soluble in water. Include molecular-level diagrams in your answer.

> The concepts of acid–base equilibria were developed in this chapter for aqueous solutions (in aqueous solutions, water is the solvent and is intimately involved in the equilibria). However, the Brønsted–Lowry acid–base theory can be extended easily to ot

> Aluminum ion may be precipitated from aqueous solution by addition of hydroxide ion, forming Al(OH)3. A large excess of hydroxide ion must not be added, however, because the precipitate of Al(OH)3 will redissolve as a soluble compound containing aluminum

> When aqueous solutions of lead(II) ion are treated with potassium chromate solution, a bright yellow precipitate of lead(II) chromate, PbCrO4, forms. How many grams of lead chromate form when a 1.00-g sample of Pb(NO3)2 is added to 25.0 mL of 1.00 M K2Cr

> Calcium oxalate, CaC2O4, is very insoluble in water. What mass of sodium oxalate, Na2C2O4, is required to precipitate the calcium ion from 37.5 mL of 0.104 M CaCl2 solution?

> Many metal ions are precipitated from solution by the sulfide ion. As an example, consider treating a solution of copper(II) sulfate with sodium sulfide solution: CuSO4(aq) + Na2S(aq) CuS(s) + Na2SO4(aq) What volume of 0.105 M Na2S s

> Which of the following combinations would act as buffered solutions? a. HCl and NaCl b. CH3COOH and KCH3COO c. H2S and NaHS d. H2S and Na2S

> The amount of nickel(II) present in an aqueous solution can be determined by precipitating the nickel with the organic chemical reagent dimethylglyoxime [CH3C(NOH)C(NOH)CH3, commonly abbreviated as “DMG”]. Ni2+(aq) + 2DMG(aq) Ni(DMG)2(

> Which component of a buffered solution consumes added strong base? Using your example from Exercise 60, show how this component would react with added NaOH.

> What is the effect on the equilibrium position if an exothermic reaction is carried out at a higher temperature? Does the net amount of product increase or decrease? Does the value of the equilibrium constant change if the temperature is increased? If so

> Ksp for magnesium carbonate, MgCO3, has a value 3.5 * 10-8 at 25 °C. Calculate the solubility of magnesium carbonate in mol/L and g/L at 25 °C.

> An oil spill spreads out on the surface of water, rather than dissolving in the water. Explain why.

> Calculate the hydrogen ion concentration, in moles per liter, for solutions with each of the following pH values. a. pH = 9.01 b. pH = 6.89 c. pH = 1.02 d. pH = 7.00

> Calculate the pH of each of the following solutions of strong acids. a. 1.21 * 10-3 M HNO3 b. 0.000199 M HClO4 c. 5.01 * 10-5 M HCl d. 0.00104 M HBr

> Calculate the hydrogen ion concentration and the pH of each of the following solutions of strong acids. a. 1.04 * 10-4 M HCl b. 0.00301 M HNO3 c. 5.41 * 10-4 M HClO4 d. 6.42 * 10-2 M HNO3

> Calculate the new molarity that results when 250. mL of water is added to each of the following solutions. a. 125 mL of 0.251 M HCl b. 445 mL of 0.499 M H2SO4 c. 5.25 L of 0.101 M HNO3 d. 11.2 mL of 14.5 M HC2H3O2

> Calculate the pH corresponding to each of the following hydroxide ion concentrations, and indicate whether each solution is acidic or basic. a. [OH-] = 4.85 * 10-5 M b. [OH-] = 3.96 * 10-7 M c. [OH-] = 1.22 * 10-10 M d. [OH-] = 5.33 * 10-12 M

> Calculate the pH corresponding to each of the hydroxide ion concentrations given below, and indicate whether each solution is acidic or basic. a. [OH-] = 4.73 * 10-4 M b. [OH-] = 5.99 * 10-1 M c. [OH-] = 2.87 * 10-8 M d. [OH-] = 6.39 * 10-3 M

> Calculate the hydrogen ion concentration, in moles per liter, for solutions with each of the following pH or pOH values. a. pOH = 4.99 b. pH = 7.74 c. pOH = 10.74 d. pH = 2.25

> Calculate the hydrogen ion concentration, in moles per liter, for solutions with each of the following pOH values. a. pOH = 4.95 b. pOH = 7.00 c. pOH = 12.94 d. pOH = 1.02

> Calculate the number of moles of each ion present in each of the following solutions. a. 10.2 mL of 0.451 M AlCl3 solution b. 5.51 L of 0.103 M Na3PO4 solution c. 1.75 mL of 1.25 M CuCl2 solution d. 25.2 mL of 0.00157 M Ca(OH)2 solution

> Given the general equation illustrating the reaction of the acid HA in water, HA(aq) + H2O(l) H3O+(aq) + A-(aq) explain why water is considered a base in the Brønsted-Lowry model.

> Calculate the number of moles of the indicated ion present in each of the following solutions. a. Na+ ion in 1.00 L of 0.251 M Na2SO4 solution b. Cl- ion in 5.50 L of 0.10 M FeCl3 solution c. NO3- ion in 100. mL of 0.55 M Ba(NO3)2 solution d. NH4+ io

> For each hydrogen ion concentration listed, calculate the pH of the solution as well as the concentration of hydroxide ion in the solution. Indicate whether each solution is acidic or basic. a. [H+] = 1.91 * 10-2 M b. [H+] = 4.83 * 10-7 M c. [H+] = 8.9

> For each hydrogen ion concentration listed, calculate the pH of the solution as well as the concentration of hydroxide ion in the solution. Indicate whether each solution is acidic or basic. a. [H+] = 4.76 * 10-8 M b. [H+] = 8.92 * 10-3 M c. [H+] = 7.0

> What mass of the indicated solute does each of the following solutions contain? a. 17.8 mL of 0.119 M CaCl2 b. 27.6 mL of 0.288 M KCl c. 35.4 mL of 0.399 M FeCl3 d. 46.1 mL of 0.559 M KNO3

> What mass of the indicated solute does each of the following solutions contain? a. 2.50 L of 13.1 M HCl solution b. 15.6 mL of 0.155 M NaOH solution c. 135 mL of 2.01 M HNO3 solution d. 4.21 L of 0.515 M CaCl2 solution

> How many moles of the indicated solute does each of the following solutions contain? a. 12.5 mL of 0.104 M HCl b. 27.3 mL of 0.223 M NaOH c. 36.8 mL of 0.501 M HNO3 d. 47.5 mL of 0.749 M KOH

> How many moles of the indicated solute does each of the following solutions contain? a. 4.25 mL of 0.105 M CaCl2 solution b. 11.3 mL of 0.405 M NaOH solution c. 1.25 L of 12.1 M HCl solution d. 27.5 mL of 1.98 M NaCl solution

> Calculate the pH corresponding to each of the following hydrogen ion concentrations, and indicate whether each solution is acidic, basic, or neutral. a. [H+] = 0.00512 M b. [H+] = 3.76 * 10-5 M c. [H+] = 5.61 * 10-10 M d. [H+] = 8.44 * 10-6 M

> Calculate the pH corresponding to each of the hydrogen ion concentrations given below, and indicate whether each solution is acidic or basic. a. [H+] = 4.02 * 10-3 M b. [H+] = 8.99 * 10-7 M c. [H+] = 2.39 * 10-6 M d. [H+] = 1.89 * 10-10 M

> Consider the reaction 2CO(g) + O2(g) ⇌ 2CO2(g) Suppose the system is already at equilibrium, and then an additional mole of CO2(g) is injected into the system at constant temperature. Does the amount of O2(g) in the system increase or decrease? Does th

> How do chemists envision reactions taking place in terms of the collision model for reactions? Give an example of a simple reaction and how you might envision the reaction’s taking place by means of a collision between the molecules.

> For a hydrogen ion concentration of 2.33 * 10-6 M, how many decimal places should we give when expressing the pH of the solution?

> Calculate the [H+] in each of the following solutions, and indicate whether the solution is acidic or basic. a. [OH-] = 2.32 * 10-4 M b. [OH-] = 8.99 * 10-10 M c. [OH-] = 4.34 * 10-6 M d. [OH-] = 6.22 * 10-12 M

> A conjugate acid–base pair consists of two substances related by the donating and accepting of a(n) .

> Of the following acids, which have relatively strong conjugate bases? a. HNO2 b. HCOOH c. HClO4 d. HNO3

> Calculate the concentration of all ions present when 0.160 g of MgCl2 is dissolved in enough water to make 100.0 mL of solution.

> Buffered solutions are mixtures of a weak acid and its conjugate base. Explain why a mixture of a strong acid and its conjugate base (such as HCl and Cl-) is not buffered.

> Why do scientists tend to express the acidity of a solution in terms of its pH, rather than in terms of the molarity of hydrogen ion present? How is pH defined mathematically?

> A buffered solution is prepared containing acetic acid, HC2H3O2, and sodium acetate, NaC2H3O2, both at 0.5 M. Write a chemical equation showing how this buffered solution would resist a decrease in its pH if a few drops of aqueous strong acid HCl solutio

> If 27.5 mL of 3.5 * 10-2 N Ca(OH)2 solution is needed to neutralize 10.0 mL of nitric acid solution of unknown concentration, what is the normality of the nitric acid?

> Which component of a buffered solution is capable of combining with an added strong acid? Using your example from Exercise 60, show how this component would react with added HCl.

> A sodium dihydrogen phosphate solution was prepared by dissolving 5.0 g of NaH2PO4 in enough water to make 500. mL of solution. What are the molarity and normality of the resulting solution?

> Calculate the normality of each of the following solutions. a. 0.50 M acetic acid, HC2H3O2 b. 0.00250 M sulfuric acid, H2SO4 c. 0.10 M potassium hydroxide, KOH

> What two components make up a buffered solution? Give an example of a combination that would serve as a buffered solution.

> According to Arrhenius, produce hydrogen ions in aqueous solution, whereas produce hydroxide ions.

> What minimum volume of 16 M sulfuric acid must be used to prepare 750 mL of a 0.10 M H2SO4 solution?

> How many grams of Ba(NO3)2 are required to precipitate all the sulfate ion present in 15.3 mL of 0.139 M H2SO4 solution? Ba(NO3)2(aq) + H2SO4(aq) BaSO4(s) + 2HNO3(aq)

> What characteristic properties do buffered solutions possess?

> For each of the following solutions, the mass of solute is given, followed by the total volume of the solution prepared. Calculate the molarity of each solution. a. 5.59 g CaCl2; 125 mL b. 2.34 g CaCl2; 125 mL c. 8.73 g CaCl2; 125 mL d. 11.5 g CaCl2;

> When 10. L of water is added to 3.0 L of 6.0 M H2SO4, what is the molarity of the resulting solution? Assume the volumes are additive.

> Calculate the pH of each of the following solutions from the information given. a. [H+] = 3.42 * 10-10 M b. pOH = 5.92 c. [OH-] = 2.86 * 10-7 M d. [H+] = 9.11 * 10-2 M

> How many milliliters of 18.0 M H2SO4 are required to prepare 35.0 mL of 0.250 M solution?

> Calculate the pH of each of the following solutions from the information given. a. [H+] = 4.78 * 10-2 M b. pOH = 4.56 c. [OH-] = 9.74 * 10-3 M d. [H+] = 1.24 * 10-8 M

> Calcium carbonate, CaCO3, can be obtained in a very pure state. Standard solutions of calcium ion are usually prepared by dissolving calcium carbonate in acid. What mass of CaCO3 should be taken to prepare 500. mL of 0.0200 M calcium ion solution?

> The “Chemistry in Focus” segment Garden-Variety Acid– Base Indicators discusses acid–base indicators found in nature. What colors are exhibited by red cabbage juice under acid conditions? Under basic conditions?

> If 10. g of AgNO3 is available, what volume of 0.25 M AgNO3 solution can be prepared?

> How do the components of a conjugate acid–base pair differ from one another? Give an example of a conjugate acid–base pair to illustrate your answer.

> How many moles of the indicated solute does each of the following solutions contain? a. 1.5 L of 3.0 M H2SO4 solution b. 35 mL of 5.4 M NaCl solution c. 5.2 L of 18 M H2SO4 solution d. 0.050 L of 1.1 * 10-3 M NaF solution

> Water is the most common amphoteric substance, which means that, depending on the circumstances, water can behave either as an acid or as a base. Using HF as an example of an acid and NH3 as an example of a base, write equations for these substances reac

> For each of the following solutions, the mass of solute is given, followed by the total volume of the solution prepared. Calculate the molarity of each solution. a. 3.51 g NaCl; 25 mL b. 3.51 g NaCl; 50. mL c. 3.51 g NaCl; 75 mL d. 3.51 g NaCl; 1.00

> Concentrated hydrochloric acid is made by pumping hydrogen chloride gas into distilled water. If concentrated HCl contains 439 g of HCl per liter, what is the molarity?

> Complete the table for each of the following solutions: [H*] pH pOH [OH=] 0.0070 М HNO, 3.0 М КОН

> Choose pairs in which the species listed first is the conjugate base of the species listed second. a. S2-, HS- b. H+, OH- c. HBr, Br- d. NO2-, HNO2

> You add 40.0 mL of water to 60.0 mL of a 2.00 M calcium chloride solution. How many moles of calcium chloride are in the new solution?

> How many moles of each ion are present in 11.7 mL of 0.102 M Na3PO4 solution?