Chapter 4

Write the molecular, ionic, and net ionic equations for the reaction between \(\mathrm{NaCl}\) and \(\mathrm{AgNO}_{3}\) solutions that forms solid \(\mathrm{AgCl}\) leaving \(\mathrm{NaNO}_{3}\) in water.

Aqueous solutions of sodium sulfide and copper(II) nitrate are mixed. A precipitate of copper(II) sulfide forms at once. The solution that remains contains sodium nitrate. Write the molecular, ionic, and net ionic equations for this reaction.

If an aqueous solution of iron(III) sulfate (a compound used in dyeing textiles and also for etching aluminum) is mixed with a solution of barium chloride, a precipitate of barium sulfate forms and the solution that remains contains iron(III) chloride. Write the molecular, ionic, and net ionic equations for this reaction.

Complete and balance the following equations. For each, write the molecular, ionic, and net ionic equations. (All of the products are soluble in water.) (a) \(\mathrm{Ca}(\mathrm{OH})_{2}(a q)+\mathrm{HNO}_{3}(a q) \longrightarrow\) (b) \(\mathrm{Al}_{2} \mathrm{O}_{3}(s)+\mathrm{HCl}(a q) \longrightarrow\) (c) \(\mathrm{Zn}(\mathrm{OH})_{2}(s)+\mathrm{H}_{2} \mathrm{SO}_{4}(a q) \longrightarrow\)

Complete and balance the following equations. For each, write the molecular, ionic, and net ionic equations. (All of the products are soluble in water.) (a) \(\mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}(a q)+\mathrm{Mg}(\mathrm{OH})_{2}(s) \longrightarrow\) (b) \(\mathrm{HClO}_{4}(a q)+\mathrm{NH}_{3}(a q) \longrightarrow\) (c) \(\mathrm{H}_{2} \mathrm{CO}_{3}(a q)+\mathrm{NH}_{3}(a q) \longrightarrow\)

Write balanced net ionic equations for the reaction between: (a) \(\mathrm{H}_{2} \mathrm{SO}_{4}(a q)+\mathrm{NaHSO}_{3}(a q)\) (b) \(\mathrm{HNO}_{3}(a q)+\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3}(a q)\)

Sodium sulfide and hydrochloric acid react to form a gas. Write the balanced molecular and net ionic equation for the reaction.

Write the balanced molecular and net ionic equation for the reaction between sulfuric acid and potassium cyanide.

Explain why the following reactions take place. (a) \(\mathrm{CrCl}_{3}+3 \mathrm{NaOH} \longrightarrow \mathrm{Cr}(\mathrm{OH})_{3}+3 \mathrm{NaCl}\) (b) \(\mathrm{ZnO}+2 \mathrm{HBr} \longrightarrow \mathrm{ZnBr}_{2}+\mathrm{H}_{2} \mathrm{O}\)

Complete and balance the molecular, ionic, and net ionic equations for the following reactions. (a) \(\mathrm{HNO}_{3}+\mathrm{Cr}(\mathrm{OH})_{3} \longrightarrow\) (b) \(\mathrm{HClO}_{4}+\mathrm{NaOH} \longrightarrow\) (c) \(\mathrm{Cu}(\mathrm{OH})_{2}+\mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2} \longrightarrow\) (d) \(\mathrm{ZnO}+\mathrm{H}_{2} \mathrm{SO}_{4} \longrightarrow\)

Write balanced molecular, ionic, and net ionic equations for the following pairs of reactants. If all ions cancel, indicate that no reaction (N.R.) takes place. (a) sodium sulfite and barium nitrate (b) formic acid \(\left(\mathrm{HCHO}_{2}\right)\) and potassium carbonate (c) ammonium bromide and lead(II) acetate (d) ammonium perchlorate and copper(II) nitrate

Write balanced molecular, ionic, and net ionic equations for the following pairs of reactants. If all ions cancel, indicate that no reaction (N.R.) takes place. (a) ammonium sulfide and sodium hydroxide (b) chromium(III) sulfate and potassium carbonate (c) silver nitrate and chromium(III) acetate (d) strontium hydroxide and magnesium chloride

Calculate the molarity of a solution prepared by dissolving (a) \(0.17 \mathrm{~mol}\) sulfuric acid in \(85 \mathrm{~mL}\) of solution. (b) \(7.5 \times 10^{-3} \mathrm{~mol}\) of sodium nitrate in a total volume of \(13.5 \mathrm{~mL}\) of solution.

Calculate the molarity of a solution that contains (a) \(2.00 \times 10^{-3}\) mol cobalt(II) sulfate in \(35.0 \mathrm{~mL}\) of solution. (b) 2.75 mole potassium hydroxide in a total volume of \(135 \mathrm{~mL}\) of solution.

Calculate the molarity of a solution prepared by dissolving (a) \(4.00 \mathrm{~g}\) of sodium hydroxide in a total volume of \(100.0 \mathrm{~mL}\) of solution. (b) \(16.0 \mathrm{~g}\) of calcium chloride in a total volume of \(250.0 \mathrm{~mL}\) of solution.

Calculate the molarity of a solution that contains (a) \(3.60 \mathrm{~g}\) of sulfuric acid in \(450.0 \mathrm{~mL}\) of solution. (b) \(0.001 \mathrm{~g}\) of iron(II) nitrate in \(12.0 \mathrm{~mL}\) of solution.

How many milliliters of \(0.265 \mathrm{M} \mathrm{NaC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\) are needed to supply \(14.3 \mathrm{~g} \mathrm{NaC}_{2} \mathrm{H}_{3} \mathrm{O}_{2} ?\)

How many milliliters of \(0.615 \mathrm{M} \mathrm{HNO}_{3}\) contain \(1.67 \mathrm{~g}\) \(\mathrm{HNO}_{3}^{?}\)

Calculate the number of grams of each solute that has to be taken to make each of the following solutions. (a) \(125 \mathrm{~mL}\) of \(0.200 \mathrm{M} \mathrm{NaCl}\) (b) \(250.0 \mathrm{~mL}\) of \(0.360 \mathrm{M} \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}\) (c) \(250.0 \mathrm{~mL}\) of \(0.250 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}\)

If \(25.0 \mathrm{~mL}\) of \(0.56 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}\) is diluted to a volume of \(125 \mathrm{~mL}\), what is the molarity of the resulting solution?

A \(150 \mathrm{~mL}\) sample of \(0.450 \mathrm{M} \mathrm{HNO}_{3}\) is diluted to \(450 \mathrm{~mL}\). What is the molarity of the resulting solution?

To what volume must \(25.0 \mathrm{~mL}\) of \(18.0 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}\) be diluted to produce \(1.50 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4} ?\)

To what volume must \(50.0 \mathrm{~mL}\) of \(1.50 \mathrm{M} \mathrm{HCl}\) be diluted to produce \(0.200 \mathrm{M}\mathrm{HCl}\) ?

How many milliliters of water must be added to \(150.0 \mathrm{~mL}\) of \(2.50 \mathrm{M} \mathrm{KOH}\) to give a \(1.00 \mathrm{M}\) solution? (Assume the volumes are additive.)

How many milliliters of water must be added to 120.0 \(\mathrm{mL}\) of \(1.50 \mathrm{M} \mathrm{HCl}\) to give \(1.00 \mathrm{M} \mathrm{HCl}\) ? (Assume the volumes are additive.)

Calculate the number of moles of each of the ions in the following solutions. (a) \(32.3 \mathrm{~mL}\) of \(0.455 \mathrm{M} \mathrm{CaCl}_{2}\) (b) \(50.0 \mathrm{~mL}\) of \(0.408 \mathrm{MAlCl}_{3}\)

Calculate the number of moles of each of the ions in the following solutions. (a) \(18.5 \mathrm{~mL}\) of \(0.402 \mathrm{M}\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3}\) (b) \(30.0 \mathrm{~mL}\) of \(0.359 \mathrm{MAl}_{2}\left(\mathrm{SO}_{4}\right)_{3}\)

Calculate the concentrations of each of the ions in (a) \(0.25 M \mathrm{Cr}\left(\mathrm{NO}_{3}\right)_{2}\), (b) \(0.10 \mathrm{M} \mathrm{CuSO}_{4}\), (c) \(0.16 \mathrm{M}\) \(\mathrm{Na}_{3} \mathrm{PO}_{4},\) (d) \(0.075 \mathrm{M} \mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3}\)

Calculate the concentrations of each of the ions in (a) \(0.060 \mathrm{M} \mathrm{Ca}(\mathrm{OH})_{2},\) (b) \(0.15 \mathrm{M} \mathrm{FeCl}_{3}\), (c) \(0.22 M\) \(\mathrm{Cr}_{2}\left(\mathrm{SO}_{4}\right)_{3}\) (d) \(0.60 \mathrm{M}\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4}\)

How many milliliters of \(0.258 \mathrm{M} \mathrm{NiCl}_{2}\) solution are needed to react completely with \(20.0 \mathrm{~mL}\) of \(0.153 \mathrm{M}\) \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) solution? How many grams of \(\mathrm{NiCO}_{3}\) will be formed? The reaction is \(\mathrm{Na}_{2} \mathrm{CO}_{3}(a q)+\mathrm{NiCl}_{2}(a q) \longrightarrow \mathrm{NiCO}_{3}(s)+2 \mathrm{NaCl}(a q)\)

How many milliliters of \(0.100 \mathrm{M} \mathrm{NaOH}\) are needed to completely neutralize \(25.0 \mathrm{~mL}\) of \(0.250 \mathrm{M} \mathrm{H}_{2} \mathrm{C}_{4} \mathrm{H}_{4} \mathrm{O}_{6} ?\) The reaction is $$ 2 \mathrm{NaOH}(a q)+\mathrm{H}_{2} \mathrm{C}_{4} \mathrm{H}_{4} \mathrm{O}_{6}(a q) \stackrel{\longrightarrow}{\mathrm{Na}_{2} \mathrm{C}_{4} \mathrm{H}_{4} \mathrm{O}_{6}(a q)+2 \mathrm{H}_{2} \mathrm{O}} $$

What is the molarity of an aqueous solution of potassium hydroxide if \(21.34 \mathrm{~mL}\) is exactly neutralized by \(20.78 \mathrm{~mL}\) of \(0.116 M \mathrm{HCl}\) ? Write and balance the molecular equation for the reaction.

How many grams of baking soda, \(\mathrm{NaHCO}_{3}\), are needed to react with \(162 \mathrm{~mL}\) of stomach acid having an \(\mathrm{HCl}\) concentration of \(0.052 \mathrm{M}\) ?

How many grams of cobalt(II) chloride are needed to react completely with \(60.0 \mathrm{~mL}\) of \(0.200 \mathrm{M} \mathrm{KOH}\) solution? The net ionic equation for the reaction is $$ \mathrm{Co}^{2+}(a q)+2 \mathrm{OH}^{-}(a q) \longrightarrow \mathrm{Co}(\mathrm{OH})_{2}(s) $$

Suppose \(3.50 \mathrm{~g}\) of solid \(\mathrm{Mg}(\mathrm{OH})_{2}\) is added to \(30.0 \mathrm{~mL}\) of \(0.500 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}\) solution. What will the concentration of \(\mathrm{Mg}^{2+}\) be when all of the acid has been neutralized? How many grams of \(\mathrm{Mg}(\mathrm{OH})_{2}\) will not have dissolved?

In a titration, \(23.25 \mathrm{~mL}\) of \(0.105 \mathrm{M} \mathrm{NaOH}\) was needed to react with \(21.45 \mathrm{~mL}\) of \(\mathrm{HCl}\) solution. What is the molarity of the acid?

A 12.5 mL sample of vinegar, containing acetic acid, was titrated using \(0.504 \mathrm{M} \mathrm{NaOH}\) solution. The titration required \(20.65 \mathrm{~mL}\) of the base. What was the molar concentration of acetic acid in the vinegar?

Lactic acid, \(\mathrm{HC}_{3} \mathrm{H}_{5} \mathrm{O}_{3},\) is a monoprotic acid that forms when milk sours. An \(18.5 \mathrm{~mL}\) sample of a solution of lactic acid required \(17.25 \mathrm{~mL}\) of \(0.155 \mathrm{M} \mathrm{NaOH}\) to reach an end point in a titration. (a) How many moles of lactic acid were in the sample? (b) How many grams of lactic acid were in the sample?

Oxalic acid, a diprotic acid having the formula \(\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4}\), is used to clean the rust out of radiators in cars. A sample of an oxalic acid mixture was analyzed by titrating a 0.1000 g sample dissolved in water with \(0.0200 M\) \(\mathrm{NaOH}\). A volume of \(15.20 \mathrm{~mL}\) of the base was required to completely neutralize the oxalic acid. What was the percentage by mass of oxalic acid in the sample?

A certain lead ore contains the compound \(\mathrm{PbCO}_{3} .\) A sample of the ore weighing \(1.526 \mathrm{~g}\) was treated with nitric acid, which dissolved the \(\mathrm{PbCO}_{3}\). The resulting solution was filtered from undissolved rock and required \(29.22 \mathrm{~mL}\) of \(0.122 \mathrm{M} \mathrm{Na}_{2} \mathrm{SO}_{4}\) to completely precipitate all of the lead as \(\mathrm{PbSO}_{4}\). (a) How many moles of lead were in the ore sample? (b) How many grams of lead were in the ore sample? (c) What is the percentage by mass of lead in the ore? (d) Would you expect the same results if the solid \(\mathrm{PbSO}_{4}\) was collected, washed, dried, and weighed and the final mass was used to answer this question?

An ore of barium contains \(\mathrm{BaCO}_{3}\). A 1.542 g sample of the ore was treated with \(\mathrm{HCl}\) to dissolve the \(\mathrm{BaCO}_{3}\). The resulting solution was filtered to remove insoluble material and then treated with \(\mathrm{H}_{2} \mathrm{SO}_{4}\) to precipitate \(\mathrm{BaSO}_{4}\). The precipi- (a) How tate was filtered, dried, and found to weigh \(1.159 \mathrm{~g}\). many moles of barium were in the ore sample? (b) How many grams of barium were in the ore sample? (c) What is the percentage by mass of barium in the ore? (d) If the molarity and volume of the sulfuric acid needed for the precipitation was noted, could you get the same answers?

If a solution of sodium phosphate (also known as trisodium phosphate, or \(\mathrm{TSP}\) ), \(\mathrm{Na}_{3} \mathrm{PO}_{4}\), is poured into seawater, precipitates of calcium phosphate and magnesium phosphate are formed. (Magnesium and calcium ions are among the principal ions found in seawater.) Write net ionic equations for these reactions.

With which of the following will the weak acid \(\mathrm{HCHO}_{2}\) react? For those with which there is a reaction, write the formulas of the products. (a) \(\mathrm{KOH},\) (b) \(\mathrm{MgO},\) (c) \(\mathrm{NH}_{3}\)

Suppose that \(25.0 \mathrm{~mL}\) of \(0.440 \mathrm{M} \mathrm{NaCl}\) is added to \(25.0 \mathrm{~mL}\) of \(0.320 \mathrm{MAgNO}_{3}\) (a) How many moles of \(\mathrm{AgCl}\) would precipitate? (b) What would be the concentrations of each of the ions in the reaction mixture after the reaction?

Classify each of the following as a strong electrolyte, weak electrolyte, or nonelectrolyte. (a) \(\mathrm{LiBr}\) (b) glucose (a sugar) (c) \(\mathrm{Ca}(\mathrm{OH})_{2}\) (d) \(\mathrm{NH}_{3}\)

Aspirin is a monoprotic acid called acetylsalicylic acid Its formula is \(\mathrm{HC}_{9} \mathrm{H}_{7} \mathrm{O}_{4}\). A certain pain reliever was analyzed for aspirin by dissolving \(0.118 \mathrm{~g}\) of it in water and titrating it with \(0.0300 \mathrm{M} \mathrm{KOH}\) solution. The titration required \(14.76 \mathrm{~mL}\) of base. What is the percentage by weight of aspirin in the drug?

How many milliliters of \(0.10 \mathrm{M} \mathrm{HCl}\) must be added to \(50.0 \mathrm{~mL}\) of \(0.40 \mathrm{M} \mathrm{HCl}\) to give a final solution that has a molarity of \(0.25 M ?\)

Qualitative analysis of an unknown acid found only carbon, hydrogen, and oxygen. In a quantitative analysis, a \(10.46 \mathrm{mg}\) sample was burned in oxygen and gave 22.17 \(\mathrm{mg} \mathrm{CO}_{2}\) and \(3.40 \mathrm{mg} \mathrm{H}_{2} \mathrm{O}\). The molecular mass was de- termined to be \(166 \mathrm{~g} \mathrm{~mol}^{-1}\). When a \(0.1680 \mathrm{~g}\) sample of the acid was titrated with \(0.1250 \mathrm{M} \mathrm{NaOH},\) the end point was reached after \(16.18 \mathrm{~mL}\) of the base had been added. (a) What is the molecular formula for the acid? (b) Is the acid mono-, \(\mathrm{di}\) -, or triprotic?

A mixture was known to contain both \(\mathrm{KNO}_{3}\) and \(\mathrm{K}_{2} \mathrm{SO}_{3}\). To \(0.486 \mathrm{~g}\) of the mixture, dissolved in enough water to give \(50.00 \mathrm{~mL}\) of solution, was added \(50.00 \mathrm{~mL}\) of \(0.150 \mathrm{M} \mathrm{HCl}\) (an excess of \(\mathrm{HCl}\) ). The reaction mixture was heated to drive off all of the \(\mathrm{SO}_{2}\), and then \(25.00 \mathrm{~mL}\) of the reaction mixture was titrated with \(0.100 \mathrm{MKOH}\) The titration required \(13.11 \mathrm{~mL}\) of the \(\mathrm{KOH}\) solution to reach an end point. What was the percentage by mass of \(\mathrm{K}_{2} \mathrm{SO}_{3}\) in the original mixture of \(\mathrm{KNO}_{3}\) and \(\mathrm{K}_{2} \mathrm{SO}_{3}\) ?

Carbon dioxide is one obvious contributor to excessive global warming. What is your plan for controlling \(\mathrm{CO}_{2}\) emissions? What are the advantages and disadvantages of your plan?